The Materials Science Graduate Student Days 2016 · 2016-02-18 · 11.20 - 11.40 High pressure jet...

The

Materials Science

Graduate Student

Days 2016

Booklet

February 23-24, 2016

Lecture hall Kollektorn, Physics

Chalmers University of Technology

Campus Johanneberg, Gothenburg

The Materials Science Graduate Student Days 2016

1

Table of contents

Program 2016 2

Posters 4

List of participants 5

Questions for group discussions 7

Abstracts - Oral presentations: 8

Maxime Van den Bossche O1

Saba Atefyekta O2

Johanna Ekberg O3

Johan Nilsson O4

Manfred Kerner O5

Johnas Eklöf O6

Maheswaran Vattur Sundaram O7

Carin Österberg O8

Philipp Hoier O9

Caroline Janson O10

Masoud Rashidi O11

Abstracts - Poster presentations: 19

Ali Alenezi P1

Martin Bergman P2

Lukas Boge P3

Andrea Boschin P4

Joakim Brorsson P5

Johanna Carlsson P6

Niklas Ehrlin P7

Cecilia Fager P8

Linda Härdelin P9

Simon Isaksson P10

Casey Jessop P11

Kristina Karlsson P12

Anand Rajasekharan P13

Simon Lindberg P14

Kristina Lindgren P15

Kajsa Markstedt P16

Dimitrios Nikas P17

Ferry A. A. Nugroho P18

Maria Pihl P19

Waqas Muhammad Qazi P20

Sakari Tolvanen P21

Peter Velin P22

Saad Sheikh P23

Xueting Wang P24

Milene Zezzi do Valle Gomes P25


2

Program 2016

Tuesday, February 23

08.30 - 09.00 Registration and mounting of posters

Chair: Lena Falk, Physics

09.00 - 09.15 Welcome

09.15 - 09.45 Invited: Shaping the future with plastics?

Christer Svanberg, Borealis

09.45 - 10.30 COFFEE and Poster session

10.30 - 11.00 Invited: Kompetensutveckling under doktorandtiden; en reflektion efter tjugo år

Maria Knutson Wedel, Vice President, Chalmers

Chair: Casey Jessop, Materials and Manufacturing Technology

11.05 - 11.25 How to find crystal and surface structures by mimicking biological evolution

Maxime Van den Bossche, Physics

11.30 - 11.50 Antimicrobial peptide functionalization of surfaces for biomedical applications

Saba Atefyekta, Chemistry and Chemical Engineering

11.55 - 12.05 Chalmers Materials Analysis Laboratory, the infrastructure unit at Applied Physics

Katarina Logg, Chalmers Materials Analysis Laboratory

12.05 - 13.00 LUNCH in the Canyon

Chair: Hanna Härelind, Chemistry and Chemical Engineering

13.00 - 13.10 The Nanofabrication Laboratory, the cleanroom facility at MC2

Ulf Södervall, Nanofabrication Laboratory, MC2

13.10 - 15.10 Lab tours: Materials Analysis Laboratory, Nanofabrication Laboratory


15.40 - 16.10 Invited: From orbitales to tidal flows

Heije Westberg, Minesto

16.15 - 16.35 Porosity measurements in Thermal Barrier Coatings obtained by Suspension

Plasma Spray process

Johanna Ekberg, Materials and Manufacturing Technology

16.35 - 16.45 LEG STRETCHER

Chair: Saba Atefyekta, Chemistry and Chemical Engineering

16.45 - 17.05 Catalytic combustion of methane studied by in-situ X-ray absorption spectroscopy

Johan Nilsson, Chemistry and Chemical Engineering

17.10 - 17.30 Ionic liquid based electrolytes for high-temperature lithium-ion batteries

Manfred Kerner, Physics

17.30 - 18.00 Poster session

18.00 DINNER at Hyllan


3

Wednesday, February 24

Chair: Mikael Rigdahl, Materials and Manufacturing Technology

09.00 - 09.30 Invited: PhD in an entrepreneurial company - challenges and opportunities

Helena Wassenius, BIM Kemi

09.35 - 09.55 Self-assembly of nanoparticles

Johnas Eklöf, Chemistry and Chemical Engineering


10.30 - 10.50 High-density PM steels by master alloy containing boron

Maheswaran Vattur Sundaram, Materials and Manufacturing Technology

10.55 - 11.15 Potential hydrogen storage materials KSiH3 investigated with neutron scattering

Carin Österberg, Physics

Chair: Kristina Lindgren, Physics

11.20 - 11.40 High pressure jet assisted machining of Ni-based superalloys - tool wear

characterization

Philipp Hoier, Materials and Manufacturing Technology

11.45 - 12.00 The Area of Advance Materials Science

Aleksandar Matic, Area of Advance Director

12.00 - 13.00 LUNCH in the Canyon

13.00 - 13.30 Invited: A research career off the beaten tenure track – some opportunities and advice

Johan Felix, Chalmers Industriteknik

13.35 - 13.55 Synthesis of transition metal ion-chelating ordered mesoporous carbons for

noble metal-free fuel cell catalysis

Caroline Janson, Chemistry and Chemical Engineering

Chair: Lena Falk, Physics

14.00 - 14.20 Development of a new generation of 12 % chromium steels: Z-phase

strengthened steels

Masoud Rashidi, Physics

14.25 - 14.40 Invited: How do you plan a career with a PhD?

Julie Gold, Physics

14.40 - 16.00 COFFEE and Group discussions

16.00 - 16.30 Summary of Group discussions

Julie Gold, Physics

16.30 - 16.45 Concluding remarks


4

Posters

P1 A Alenezi Controlled drug release using thin polymer coatings

P2 M Bergman Solid polymer electrolytes based on PEC and a binary LiTFSI:LiBOB salt

mix

P3 L Boge Lipid-based liquid crystals as carriers for antimicrobial peptides: phase

behavior and antimicrobial effect

P4 A Boschin Characterization of Sodium Based Ternary Polymer Electrolytes

P5 J Brorsson Development of nanostructured thermoelectric materials

P6 J Carlsson Studies of Automotive Catalyst Deactivation

P7 N Ehrlin Cathodic Hydrogen Charging of IN718 – Evaluation and Simulation

P8 C Fager Determination of 3D microstructure of different types of coatings for

controlled drug release

P9 L Härdelin Extraction and Characterisation of Arabinoxylan from Barley Husk

P10 S Isaksson Energy efficient water treatment using the blueprint of nature: Utilizing

aquaporins, lipids and mesoporous silica to purify water

P11 C Jessop 3D characterization of rolling contact fatigue crack networks

P12 K Karlsson Foaming of hydroxypropyl methyl cellulose: Microstructure and mechanical

properties

P13 A Rajasekharan Bone Inspired Materials

P14 S Lindberg Novel materials for hybrid super capacitors

P15 K Lindgren Ageing of RPV steel – an atom probe tomography study

P16 K Markstedt Modification of galactoglucomannans for development of interpenetrating

networks

P17 D Nikas Characterization of microstructural changes in railway wheel steels using

orientation imaging microscopy

P18 F Nugroho Plasmonic Nanospectroscopy Sheds Lights on the Properties of Materials for

Energy Applications

P19 M Pihl Bacterial biofilm elimination using localised surface plasmon resonance

generated heat

P20 W Qazi A swallowing model for efficient food product development

P21 S Tolvanen Defect formation during laser welding and their effect on mechanical

properties of Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo

P22 P Velin Understanding the Inhibiting Effect of Water on Methane Oxidation Catalysts

P23 S Sheikh High-Entropy Alloys (HEAs)--Alloyed pleasures or Multimetallic cocktails

P24 X Wang Direct Conversion of Methane to Methanol (DCMM) over Cu-Exchanged

Zeolites

P25 M Gomes Enzyme Immobilization in Modified Mesoporous Silica for CO2 Reduction


5

List of participants

Abhijit Venkatesh PhD student MoT

Ali Alenezi PhD student Faculty of Odontology, Malmö University

Amine Yousfi PhD student F

Anand Kumar PhD student K

Andrea Boschin PhD student K

Anna-Karin Hellström PhD student K

Antonio Mulone PhD student MoT

Carin Österberg PhD student F

Carl-Robert Florén PhD student K

Caroline Janson PhD student K

Casey Jessop PhD student MoT

Cecilia Fager PhD student F

Christer Svanberg Invited speaker Borealis

David Kiefer PhD student K

Dimitrios Nikas PhD student MoT

Ferry Nugroho PhD student F

Gunnar Símonarson PhD student K

Hanna Härelind Director of studies K

Heije Westberg Invited speaker Minesto

Helena Wassenius Invited speaker BIM Kemi

Joakim Brorsson PhD student K

Johan Felix Invited speaker Chalmers Industriteknik

Johan Nilsson PhD student K

Johanna Carlsson PhD student K

Johanna Ekberg PhD student MoT

Johnas Eklöf PhD student K

Joraine Rössler Industry PhD student MoT, Swerea IVF

Julie Gold Invited speaker F

Kajsa Markstedt PhD student K

Kristina Karlsson PhD student MoT

Kristina Lindgren PhD student F

Lena Falk Director of studies F


6

Leo Svenningsson PhD student K

Linda Härdelin PhD student K

Liyang Yu PhD student K

Lukas Boge Industry PhD student K, SP Technical Research Institute

Maheswaran Vattur Sundaram PhD student MoT

Manfred Kerner PhD student F

Maria Knutson Wedel Invited speaker Chalmers

Maria Pihl Post doc K

Martin Bergman PhD student F

Masoud Rashidi PhD student F

Mats Hulander PhD student K

Maxime Van den Bossche PhD student F

Mikael Rigdahl Director of studies MoT

Milene Zezzi do Valle Gomes PhD student K

Negin Yaghini PhD student K

Niklas Ehrlin PhD student MoT, Malmö University

Peter Velin PhD student K

Philipp Hoier PhD student MoT

Saad Sheikh PhD student MoT

Saba Atefyekta PhD student K

Sakari Tolvanen PhD student MoT

Silvia Tuzi PhD student F

Simon Isakson PhD student MoT

Simon Isaksson PhD student K

Simon Lindberg PhD student F

Waqas Muhammad Industry PhD student MoT, SP Food and Bioscience

Xueting Wang PhD student K

F = Physics

K = Chemistry and Chemical Engineering

MoT = Materials and Manufacturing Technology


7

Questions for Group Discussion

Some questions and issues of relevance for planning a career with a PhD…

Expectations:

1. What is expected of employees with PhD’s? For example, are they expected to be leaders

of research groups? Be decision makers? Have good problem solving abilities? Perform

research tasks independently? Expected to design, carry out and report results of research

and/or product development projects? Expected to know project economy/budgeting?

Project management? Project leadership? Patent issues? Regulatory issues? Are they

expected to have good written and oral communication skills? Good command of English

language? Good computer skills?

During PhD:

2. During my doctoral education, how can I best prepare for a career in industry, alternative

academia?

3. What do I need to do to optimize my chances of getting employed with a PhD?

Thesis:

4. Will future employees read our thesis, either during the application process or after a

position is secured?

5. How much does the subject of our PhD thesis influence our future? What is more

important – the subject/topic or the quality of the thesis work when looking for a job?

Planning for career:

6. Which type of working environment(s) are there for PhD’s? Industry, Academia, Funding

agencies or governmental agencies dealing with research issues, Patent bureaus,

consulting company, other?

7. What are the possible career paths for PhD’s in specific industry or academic

organizations (e.g. research vs. management)

8. What are the relative weights of our PhD degree vs. BSc/Civ.eng/MSc degrees when

looking for a job? How are our undergraduate degrees viewed when looking for a job with

a PhD? How important is it to do a post doc after the PhD degree?


8

Abstracts - Oral Presentations

O1 How to find crystal and surface structures by mimicking biological evolution

Maxime Van den Bossche*, Henrik Grönbeck*, Björk Hammer**

* Dept. of Applied Physics and Competence Centre for Catalysis, Chalmers, Göteborg, Sweden

** Dept. of Physics and Astronomy, Aarhus Universitet, Aarhus, Denmark

Resolving the arrangement of atoms in crystals and at surfaces is mandatory for fundamental

understanding of material properties. One example is heterogeneous catalysis, where knowledge

on the bulk and surface structure is required before attempts to model the surface reactions can be

made.

There are many experimental methods available that offer structural information, based on e.g. X-

ray, electron, and neutron diffraction. However, experiment alone is not always successful in

solving the structure. Therefore, it is advantageous to complement experimental efforts with

theoretical methods for structure determination. Importantly, theoretical search tools are not limited

to already existing materials, but can be used for development of yet unsynthesized materials with

desired properties.

Genetic algorithms (‘GA’) form one type of

search strategies that have proven to be relatively

successful. The GA is inspired by biological

evolution, in the sense that it iteratively improves

a population through natural selection and that

genetic operators create new members from

existing ones (see Figure 1).

In this project, we have been able to improve the

efficiency of the ‘ASE’ GA code [1] for finding

surface structures, by refining the, so-called cut-

and-splice operator and by exploiting the natural

tendency towards symmetrical structures.

Furthermore, the code has been extended by

implementation of standard operators for

determining bulk crystal structures [2]. The main

showcases are ultrathin surface oxides on Pd and

bulk rutile TiO2.

Figure 1: Illustration of how genetic operators create new candidate structures. (a) The ‘cut-and-splice’

operator combines random fractions of each parent structure into a new one. (b) The ‘strain’ mutation

generates a new structure by applying a random strain to the original one.

References

1. Vilhelmsen L.B., Hammer B., J. Chem. Phys. 144, 044711 (2014).

2. Lyakhov A.O. et al., Comp. Phys. Comm. 184, 1172-1182 (2013).


9

O2

Antimicrobial peptide functionalization of surfaces for biomedical

applications

Saba Atefyekta*, Maria Pihl* and Martin Andersson*

*Dept. Chemistry and Chemical engineering, Chalmers University of Technology, Swedem

The development of antibacterial surfaces using antimicrobial peptides (AMP) seems to be a very

attractive approach for biomaterials applications. Compared to conventional antibiotics these

peptides are shown to have broader spectrum of activity and rarely promote bacterial resistance.

Moreover most of antimicrobial peptides have very wide spectrum of antimicrobial activity with

low toxicity to mammalian cells.1 Covalently bonded to a biomaterial surface, such peptides can

retain their bactericidal activities and act at very low concentrations.

In this work an antimicrobial peptide (RRPRPRPRPWWWW-NH2) was covalently bonded to

substrates coated with recombinant elastin like protein and the bacteria (S.epidermidis) response to

these surfaces were studied by microscopy methods. Recombinant elastin proteins (ELP) are

widely used components in the field of biomaterials.2 ELP containing RGD sequences and specific

photo reactive sites in their structures was used to coat substrates for subsequent attachment of

antimicrobial peptides. Such coatings can provide favorable cell-adhesive and antibacterial

surfaces for future in vivo interactions.

Uniform photo reactive ELP thin film were formed by spin coating, followed by crosslinking with

UV radiation and imaged by scanning electron microscopy. NHS/EDC coupling method was used

to covalently bond AMP to ELP surfaces. The surfaces were used to grow S.epidermdis and the

results showed a significant bactericidal effect when the films were functionalized by antimicrobial

peptides.

Figure 1. Fluorescent microscopy images of live(green) and dead(red) stained S.Epidermidis. a)glass

substrates(control) b)ELP coated surfaces c)EDC/NHS activated ELP surfaces and d) AMP functionalized ELP

surfaces.

The ease and scalability of producing ELP coatings and Antimicrobial peptides functionalization

process, makes these surface modification an ideal candidate for the development of novel

antimicrobial surfaces for biomedical applications.

References

1. Humblot, V. et al. The antibacterial activity of Magainin I immobilized onto mixed thiols Self-

Assembled Monolayers. Biomaterials 30, 3503–12 (2009).

2. Raphel, J et al. Photoreactive elastin like proteins for use as versatile bioactive materials and surface

coatings. J Mater Chem 18, 1199–1216 (2013).


10

O3

Porosity measurements in Thermal Barrier Coatings obtained by

Suspension Plasma Spray Process

Johanna Ekberg, Uta Klement

Materials and Manufacturing Technology, Chalmers University of Technology, 412 96 Gothenburg, Sweden

Thermal barrier coatings (TBCs) are used in the hot section of gas turbines to protect the underlying

components from high temperature loads. They extend the lifetime of the turbine but also allow for

a higher combustion temperature which enhances the engine efficiency and results in lower

emissions. Axial suspension plasma spraying (ASPS) is a relatively new, innovative plasma spray

technique using a feedstock consisting of fine powder particles suspended in a liquid. With ASPS,

thermal barrier coatings (TBCs) with columnar microstructures built up by fine powder particles

have been produced. The microstructure consist of both nm-sized, µm-sized and macro-pores. The

wide pore size range including nano-porosity makes it a challenge to find a technique to measure

porosity and pore size distribution in these TBCs. However, it is important to investigate the

porosity as it affects the thermal conductivity. Hence, the aim with this presentation is to introduce

two new characterization technique for determining porosity TBCs produced by ASPS. The study

is supported by microstructural characterization using scanning electron microscopy (SEM).


11

O4

Catalytic Combustion of Methane Studied by In Situ X-ray

Absorption Spectroscopy

Johan Nilsson, Per-Anders Carlsson, Natalia M. Martin, Emma C. Adams, Henrik Grönbeck*,

and Magnus Skoghlundh

Department of Chemistry and Chemical Engineering, Chalmers University of Technology

*Department of Applied Physics, Chalmers University of Technology

The catalytic combustion of methane is an important process in both energy conversion and exhaust

aftertreatment. Methane is the most difficult hydrocarbon to oxidise catalytically since the methane

molecule is symmetric and it is difficult to polarise the strong carbon hydrogen bonds. In this work

a palladium catalyst supported on alumina was studied during rich/lean cycling with an oxygen

concentration of 0.15 and 1.5%, respectively, and a constant methane concentration of 0.1%. In-

situ X-ray absorption (XAS) spectra were measured using the energy dispersive XAS technique at

beamline ID24 at ESRF, Grenoble, France.

Panel (a) shows the XAS spectra recorded at 360°C during the rich periods without oxygen and

lean periods with oxygen, the largest change in the spectra can be seen in the so called whiteline

area at about 24.37 eV. Panel (b) and (c) shows the mass spectrometry outlet concentrations

together with the XAS whiteline intensity as a function of time with 0.15 and 1.5% oxygen,

respectively. With 0.15% oxygen the highest methane conversion is found just following the

switches between the rich and lean periods, while for 1.5% oxygen the highest conversion is found

at the end of the lean period. The whiteline intensity increases as palladium in the catalyst becomes

more oxidised and using a higher oxygen concentration results in a stronger oxidation of palladium.

The oxidation state of palladium is of high importance in the catalytic reaction. During the lean

period the methane conversion is quite low when pulsing 0.15% oxygen, here the palladium surface

is likely covered with adsorbed oxygen or a surface oxide. When pulsing 1.5 % oxygen palladium

is bulk oxidised and over this surface a higher methane conversion is observed.


12

O5

Ionic Liquid Based Electrolytes for

High-Temperature Lithium-Ion Batteries

Manfred Kerner*, Nareerat Plylahan, Johan Scheers and Patrik Johansson

Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg, Sweden

E-mail: [email protected]

Today, lithium-ion batteries (LIBs) are ubiquitous in mobile phones, laptops, and other portable

devices. The research community strives to further improve the LIB to increase electric driving

distance and efficiency of both hybrid electric vehicles (HEVs) and fully electric vehicles (EVs).

Conventional LIBs need to be strictly temperature controlled, most often cooled, to ca. 30°C, to

ensure an acceptable and predictable lifetime. Increasing the thermal stability and hence making

possible operating temperatures of up to ca. 100°C would enable a merging of the cooling systems

of the LIB and the power electronics – resulting in an overall reduced system complexity, saved

mass, and a higher energy efficiency.

All components of the LIB must be thermally stable to deliver the targeted performance and

lifetime. The electrolytes of conventional LIBs all contain organic solvents and lithium salts, the

former flammable with high vapour pressures and the latter meta-stable at room temperature and

unstable at temperatures above 60°C. Thus more stable solvents and salts are needed to improve

the inherent safety of the electrolyte – especially if aiming at elevated operating temperatures.

There has been a lot of research focused on ionic liquids (ILs) incorporating the xFSI anions;

bis(trifluoromethanesulfonyl)imide (TFSI) or bis(fluorosulfonyl)imide (FSI), due to their high

thermal stabilities and conductivities [1-2], the FSI anion additionally being suggested to prevent

the Al current collector corrosion plaguing electrolytes based on TFSI.

Here, we have investigated the ILs 1-ethyl-3-methylimidazolium TFSI (EMITFSI) and EMIFSI in

combination with the Li-salts LiTFSI and LiFSI – giving four sets of electrolytes, with up to

20 mol% Li-salt. All investigated ILs and electrolytes were characterized about their thermal and

electrochemical stabilities, ionic conductivities, liquid ranges and lithium solvation numbers (SN).

These initial fundamental property studies have identified a few specific electrolytes now being

tested vs. novel electrodes developed – in order to create a working HT-LIB cell [3].

References

1. J. Pitawala et al. J. Phys. Chem. B, 2009, 113, 10607–10610.

2. J. Huang et al. J. Phys. Chem. C, 2010, 114, 21840–21847.

3. “From road-to-load“– a Swedish Foundation for Strategic Research (SSF) project.


13

O6

Self-Assembly of Nanoparticles

J. Eklöf, K. Moth-Poulsen, S. Lara-Avila

Department of Chemistry and Chemical Engineering, Department of Microtechnology and Nanoscience-MC2

Chalmers University of Technology, Polymer Technology, SE-412 96.

[email protected]

The assembly of nanoparticles are used in a vast variety of scientific areas. For instance Au assisted III-V

nanowire growth, where nanoparticles acts as catalyst in the MOVPE process1. The characteristic plasmonic

properties makes arrays of assembled nanoparticles attractive to use in sensing devices2. They could also be

used in biochemistry and improve the adhesion between electrodes and organic tissue3. Nanoparticles are

also interesting for the next generation of nanometer sized electronic devices4. It is therefore important to

investigate how the interactions between nanoparticles and substrate affects the deposition and see if it is

possible to control the deposition by varying the parameters of the deposition. We have in this work focused

on the deposition of citrate coated nanoparticles suspended in aqueous solution on Si (100).

Previous authors have shown that the conditions of the solutions are of vital for the depositions of

nanoparticles, parameters such as PH, ion concentration, temperature, particle concentration and more will

affect the density of particles found on the surface5. In this work we investigate how the doping of the Si,

O2 plasma treatment and activation using APETS or polylysine will affect the deposition.

The result images taken by SEM were analyzed by SPATSTAT, a software package for the statistical image

processing program R and Ripley’s k-function where used to see if the position of the particles on the Si

followed any specific pattern after deposition6. The density of particles where calculated using MATLAB.

Results shows that no particles will stick on untreated Si, no matter doping or plasma treatment.

Subsequently it is possible to see that the particles deposit according to a close range order where there are

a nearest neighbor distance between the particles. Results in Figure 1 also shows that O2-plasma treated Si

activated with APTES (B, Figure 1) has the shortest nearest neighbor distance and that this distance

increases if the plasma step is skipped (A, Figure 1). Polylysine affects the position of the particles

differently, where the n doped Si without any plasma treatment (C, Figure 1) step has the shortest nearest

neighbor distance between the particles. This could be because of the difference in interaction between

APTES and polylysine on Si, where APTES forms covalent bounds. It is however clear that it is possible to

control the deposition of nanoparticles by changing the surface activation method.

Figure 1: SEM images with n-doped Si(100) deposition time 1hr, treated with APTES (a), treated with O 2-

plasma followed by APTES (b), treated with polylysine (c), treated with O 2-plasma followed by polylysine.

References

1. K. A., Dick Prog. Cryst. Growth Charact. Mater., 2008, 54, 138-173.

2. T. A. Gschneidtner, Y. A. Diaz-Fernandez, S. Syrenova, F. Westerlund, C. Langhammer, K. Moth-Poulsen.

Langmuir, 2014, 30, 3041-3050

3. P. Farrahi, G. Yang, G. Kim, M. R. Abidian, Adv. Mater., 2014, 26, 1846-1885. 4. L. Sun, Y. A. Diaz-Fernandez, T. A. Gschneidtner, F. Westerlund, S. Lara-Avila, K. Moth-Poulsen, Chem. Soc.

Rev., 2014, 43, 7378-7411.

5. K. Greben, P. Li, D. Mayer, A. Offenhäusser, R. Wördenweber, J. Phys. Chem. B., 2015, 119, 5988-5994.

6. P. Diggle, Statistical Analysis of Spatial and Spatio-Temporal Point Patterns, CRC Press, London, 2013, third

edition


14

O7

High-density PM Steels by Master Alloy Containing Boron

Maheswaran Vattur Sundaram , Kumar Babu Surreddi, Eduard Hryha, Lars Nyborg

Department of Materials and Manufacturing Technology, Chalmers University of Technology, Gothenburg

High-performance PM steels for demanding applications are of significant interest for PM industry.

Flexibility in alloy design and low cost are prerequisites for successful PM implementation of such

materials. Reaching near full density through conventional press and sintering is not viable and

limits the usage of PM steel components for high performance and demanding applications.

Utilizing LPS (liquid phase sintering) through master alloy additions is one approach for achieving

high density. This study addresses the LPS behaviour of a mix of Ni-Mn-B master alloy with pure

iron and Mo-alloyed steel powders. The liquid phase generation was assessed by means of DSC

and related to the microstructure and mechanical properties of compacts from interrupted sintering

trials. The effect of initial density of the compacts on the densification behaviour was also

investigated. The results obtained clearly indicate that the master alloy addition effectively

enhances the densification behaviour and the resultant mechanical properties.


15

O8

Potential hydrogen storage materials KSiH3 investigated with

neutron scattering

Carin Österberg1, Ulrich Häussermann2, Henrik Fahlquist2, Craig M. Brown3, Terrence J.

Udovic3 and Maths Karlsson1

1Department of Applied Physics, Chalmers University of Technology, Sweden, 2Department of Materials and Environmental Chemistry, Stockholm University, Sweden,

3NIST Center for Neutron Research, National Institute of Standards and Technology, United States

Currently, there is a large effort devoted to the development of technologies that use hydrogen as an energy

source. Recently it has been shown that the alkali silanides ASiH3 (A = K and Rb) are promising materials,

which are able to store up to 4.3% of hydrogen reversibly within a p-T window that fits perfectly for several

technological applications [1]. At temperatures below 200 K ASiH3 (A = K and Rb) are characterized by an

ordered phase (β), whereas at higher temperatures they are characterized by a disordered phase (α) [2].

Structure analysis of the α-phase has established a structure, with the hydrogen atoms represented by a

quasi-spherical environment with 24 H positions surrounding one Si atom [1,3], see Fig. 1 (a). However,

the reported structural investigations also report a large spread of the Si-H bond length, from 1.47 to 1.52

Å. Here, the upper value, 1.52 Å corresponds more closely to the bond length for SiH-3 anions in solution

([2] and references therein), which may indicate that the SiH-3 anions show a quite more free rotational

behavior, as in solution or even as in a gaseous phase [2]; hence this would suggest that the phase transition

is dynamic rather than static in nature.

Fig. 1: (a) The structure of α-ASiH3 with 24 H positions (white) surrounding the Si atom (black). (b) EISF of KSiH3

at 310 K and fitted with a model of 24 H sites situated around the Si atom with 10% of the hydrogen immobile

(blue).

In order to clarify this issue, we have investigated here the rotational motions of the pyramidal SiH-3 ions in

the alkali silanides ASiH3 (A = K and Rb) by means of quasielastic neutron scattering. A key result is that

we found a strong quasielastic phase transition when going from 200 K and up in temperature, which would

then verify that the α-phase is indeed dynamic in nature. A comparison between the experimental and

calculated elastic incoherent structure factor (EISF) [Fig. 1 (b)] for the α-phase, suggests that the SiH-3

anions undergo a rotational motion, resulting in 24 H sites positioned around the Si atom with approximately

10% of the H atoms immobile. This result is in agreement with the structure depicted in Fig. 1(a).

References

1. Chotard, J. -N. et al. Chem. Eur. J. 2011, 17, 12302-12309.

2. Kranak, V. F. et al. Inorg. Chem. 2015, 54, 2300-2309 3. Tang, W. S. et al. J. Phys. Chem. C 2014, 118, 3409-3419.


16

O9

High Pressure Jet Assisted Machining of Ni-based superalloys – Tool

wear characterization

Philipp Hoier, Uta Klement

Materials and Manufacturing Technology, Chalmers University of Technology, 412 96 Gothenburg, Sweden

Ni-based superalloys are a unique class of materials with both excellent strength and corrosion

resistance at high temperatures. Therefore they find extensive application in the hot sections of

aircraft engines, where they account for up to 50 % of the total weight. Its excellent high

temperature properties however make the fabrication of components by means of conventional

metal cutting very challenging. This is mainly attributed to the generation of high temperatures and

stresses in the cutting zone which in turn lead to rapid degradation of the cutting tools.

Conventionally, coolant is supplied by means of uncontrolled flooding of the cutting zone. In this

way, zones of highest temperature are not penetrated and therefore no effective temperature

reduction is achieved.

High Pressure Jet Assisted Machining (HPJAM) is a high performance cooling strategy which

involves directing high pressure coolant jets precisely into the cutting zone. Numerous publications

are reporting reduced cutting temperatures along with longer tool life which is the basis for

application of higher cutting parameters. Hence higher metal removal rates can be achieved which

is highly beneficial in terms of overall productivity.

Despite the presence of studies regarding the positive influence of the high pressure coolant jet on

the wear rate, there is a lack of understanding the basic mechanisms behind the tool wear

mechanisms being involved. This work aims at closing this knowledge gap by characterizing flank

wear of uncoated cemented carbide tools which were used in HPJAM tests.


17

O10

Synthesis of Transition Metal Ion-chelating Ordered Mesoporous

Carbons for Noble Metal-free Fuel Cell Catalysts

Caroline Janson, Anders Palmqvist

Dept. Chemical and Biological Engineering, Chalmers University of Technology

Fuel cells are of great interest as energy conversion devices with high potential to efficiently

convert chemical energy to electricity. Nevertheless, the main reason to the fuel cells’ slow

commercial development and limited market introduction over the last decades is mainly due to

the current use of expensive noble metal-based catalysts. In order to make fuel cells economically

competitive to other energy conversion devices the cost of the catalyst has to be reduced. Therefore,

it is of interest to develop new noble metal-free catalysts with similar properties in terms of catalyst

conversion efficiency and operation stability as platinum. Another important requirement in

developing such catalysts is to achieve a low degree of complexity of the catalyst preparation in

order to further reduce cost. This project aims to design and synthesize materials with the purpose

to find a simple, inexpensive way to prepare efficient noble metal-free catalysts.


18

O11

Development of a new generation of 12% chromium steels:

Z-phase strengthened steels

M Rashidi, F Liu, H-O Andrén

Department of Applied Physics, Chalmers University of Technology, SE-412 96, Göteborg, Sweden

Fossil-fuel fired steam power plants provide more than 60% of the electricity generated worldwide,

and account for about one third of the global CO2 emissions. The thermal efficiency of the steam

power plants is limited by the maximum allowed steam temperature and pressure, which in turn

are determined by the long-term corrosion and creep resistance of economically viable materials.

Today’s best martensitic steels contain 9% Cr and can be used at ~ 600°C/300 bar. All attempts so

far to reach 650°C with 11-12% Cr steels have failed, and the reason is the formation of a complex

nitride, Z-phase, after a few years of service.

In my work, it is shown that Z-phase can be used as strengthening rather than weakening phase to

develop a new generation of martensitic steels. These steels contain 12% Cr for better corrosion

resistance and densely distributed fine Z-phase precipitates for creep resistance. A high Cr content

together with Ta and N additions were used to stimulate the formation of a fine distribution of Z-

phase in two trial steels. Atom probe tomography, transmission electron microscopy, and scanning

electron microscopy were employed for a detailed characterization of the microstructure.

In the first trial steel, 12Cr7CoTa-uLC, the C content was limited to 0.005 wt%, which resulted in

a fast transformation from TaN to CrTaN Z-phase, and subsequently a fine distribution of Z-phase

was achieved. In the second trial steel, 12Cr3CoTa-HC, a higher C content of 0.06 wt% was used,

which resulted in a slower phase transformation from Ta(C,N) to CrTaN Z-phase.

In the 12Cr7CoTa-uLC trial steel Laves phase formed continuously at the prior austenite grain

boundaries, which gave poor impact toughness. In the second trial steel, the addition of Cu and a

higher C content improved the distribution of Laves phase, and equiaxed Laves phase particles of

a few hundred nanometer in size formed resulting in improved toughness.


19

Abstracts - Poster Presentations

P1

Controlled drug release using thin polymer coatings

Ali Alenezi*, Mats Hulander**, Martin Andersson**

*Faculty of Odontology, Malmo University, **Applied surface chemistry, Chalmers University of technology

Poly (N-isopropylacrylamide) (PNIPAm) polymer has been widely examined as a smart drug

delivery material. One of its unique features is the rapid phase transition observed upon external

temperature changes close to physiologic body temperature. PNIPAm has a lower critical

solution temperature (LCST) around 34 °C. Above (LCST), the PNIPAm will collapses and

expels the solution from within and generally becomes stiff and opaque. This property can be

utilized as an effective transport means for drug delivery. We studied drug release profile from

thin polymer coatings layers. Differential scanning caliometery (DSC) was used to determine the

phase transition temperature for PNIPAm homopolymer and PNIPAm co-polymerized with 5%

and 10% of acrylamide. The polymer was later on formed as thin layer by spin coating then

immersed in (phenol) solution as it was selected as model drug. High magnification using SEM

showed 300 nm layers with uniformed thickness. Drug release and uptake were evaluated by UV-

vis spectroscopy after immersion the layers in water path. The thin polymer layer was subjected

to several cycles of Heat (on and off) from room temperature up to 60 °C. The phenol was

successfully released open heat and was uptake by layer every time the heat source was removed

(Figure 1). Additionally, release profile showed maximum phenol release in the first 15 minutes

of layers heating. Differential scanning caliomertry analysis revealed phase transition temperature

at 34.5 °C for PNIPAm homopolymer while PNIPAm Co-polymerized with 5% and 10% of

acrylamide showed phase transition at higher temperature, (41.9 and 46 °C, respectively). The

thin PNIPAAm coatings have potential applications in controlled release of therapeutic agents at

physiologic body temperature.

Figure 1: Monitoring phenol release from thin PNIPAAm coatings using UV-vis spectroscopy, (n=7)

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20

P2

Solid polymer electrolytes based on PEC and a binary

LiTFSI:LiBOB salt mix

Martin Bergman*, Daniel Brandell**, Patrik Johansson*

*Department of Applied Physics, Chalmers University of Technology, SE-41296, Gothenburg, Sweden

**Department of Chemistry - Ångström Laboratory, Uppsala University, Box 538, SE75121, Uppsala

For high temperature battery application (ca. 80-120 °C) the solid polymer electrolyte (SPE)

concept is promising, c.f. the Autolib’ battery [1], but both the mechanical stability and the ionic

conductivity must be further targeted. Polycarbonates have previously been pushed aside due to

their high glass transition temperature and subsequent low room temperature conductivity, but at

high temperatures this high Tg could instead be advantageous and provide a higher mechanical

stability.

Here a series of SPE's comprised of poly(ethylene carbonate) and a binary salt mix of the flexible

LiTFSI and the more rigid LiBOB were investigated (Figure 1). The effect of binary salt has not

been extensively studied and the different properties of the anions could lead to improved Li+

transport. The molar ratio of monomer to salt was 9, 16, and 20, and the LiTFSI:LiBOB ratio was

100:0, 75:25, 50:50, 25:75, and 0:100.

Figure 1: The PEC, LiTFSI, and LiBOB polymer structures.

The SPE's were characterized for phase transitions and thermal stability (DSC, TGA), conductivity

(dielectric spectroscopy), and for the molecular level interactions e.g. charge carriers (Raman

spectroscopy).

Acknowledgements: This work has been funded by the Swedish Foundation for Strategic Research

(“SSF”) project “From Road-to-Load.”

References

1. M. Broussely. Battery Requirements for HEVs, PHEVs, and EVs: An Overview. Electric and Hybrid

Vehicles. 2010


21

P3

Lipid-based liquid crystals as carriers for antimicrobial peptides:

phase behavior and antimicrobial effect

Lukas Boge1, Helena Bysell1, Lovisa Ringstad1, David Wennman2, Anita Umerska3, Viviane

Cassisa4, Marie-Laure Joly-Guillou4, Jonny Eriksson5, Katarina Edwards5, Martin Andersson6

1 SP Technical Research Institute of Sweden, Sweden, 2 SP Process Development, Sweden. 3 University of Angers,

France, 4 Centre Hospitalier Universitaire Angers, France, 5 Uppsala University, Sweden, 6 Chalmers University of

Technology, Sweden

Introduction

The number of antibiotic-resistant bacteria is increasing worldwide and the demand for novel

antimicrobials is constantly growing. Antimicrobial peptides (AMPs) could be an important part

of future treatment strategies of various bacterial infection diseases. However, AMPs have

relatively low stability due to proteolytic and chemical degradation. As a consequence, carrier

systems protecting the AMPs are highly needed for achieving efficient treatments. In this work,

liquid crystalline (LC) structures were examined as carriers for three AMPs: AP114, DPK-060 and

LL-37. Both bulk LC gels and liquid crystalline nanoparticles (LCNPs), i.e. cubosomes and

hexosomes, were investigated.

Methods

Characterization of the LC structures was performed using small-angle x-ray scattering, dynamic

light scattering, ζ-potential, cryogenic transmission electron microscopy and peptide loading

efficacy by ultra-performance liquid chromatography. The antimicrobial effect of the LCNPs was

investigated in-vitro using minimum inhibitory concentration and time-kill kinetics tests on several

bacterial strains.

Results

The most hydrophobic peptide (AP114) was shown to induce an increase in negative curvature of

the cubic LC system. The most polar peptide (DPK-060) induced a decrease in negative curvature

while LL-37 did not change the LC phase. The hexagonal LC phase was not affected by any of the

AMPs. The cubic LCNPs showed lower peptide loading efficacies (41-86 %), compared to the

hexagonal particles (>94 %). Moreover, peptides AP114 and DPK-060 loaded cubosomes showed

preserved antimicrobial activity, whereas LL-37 loaded particles displayed a loss in its bactericidal

properties. AMP loaded hexosomes showed a reduction in antimicrobial activity.

Discussion and conclusion

The AMPs strongly influenced the LC structure of the cubic GMO/water system. Peptide net

charge and hydrophobicity was important factors affecting the curvature changes. Results indicate

that a quick release of AMPs was taking place from the cubosome carriers, giving rise to

antibacterial effect comparable to pure peptide. The reduction in antibacterial activity for the

hexosome carriers is probably due to slow release of peptide.


22

P4

Characterization of Sodium Based Ternary Polymer Electrolytes

Andrea Boschin and Patrik Johansson

Applied Physics, Chalmers University of Technology, SE- 412 96 Göteborg Sweden,

At present sodium ion batteries (SIBs) represent a possibly cheaper and more sustainable

alternative to lithium ion batteries [1]. Indeed, while sodium shows similar chemical and

electrochemical properties to lithium, paving the way for fast development, the resources of sodium

are in principle unlimited. The SIB electrolyte research is diverse; organic solvents, polymers, and

ionic liquids are all being used as matrices [1-3]. Ion conducting solid polymer electrolytes (SPEs)

avoid the usage of organic solvents and can thereby enable fabrication of flexible, safe and compact

solid-state structures. The ionic conductivities of sodium and lithium SPEs, based on poly (ethylene

oxide) (PEO) are comparable [4-6], however, both having rather low conductivity values: (10-7-10-

5) Scm-1 at room temperature.

The main part of the research performed so far on Na+ conducting SPEs was carried out during the

1990’s [5-6]. Recently [7], we have characterized the binary SPE systems NaTFSI-PEO and

NaFSI-PEO, where basically the TFSI anion acts inhibiting on crystallization, as previously shown

for the corresponding Li-based SPEs [8], while the FSI anion, despite being chemically very

similar, seems to favor it – in these often semi-crystalline systems. The highest ionic conductivity

at 20°C was obtained for NaTFSI(PEO)9.

In order to further improve the ionic conductivity without compromising safety [9], different

amounts of N-propyl-N-methyl-pyrrolidinium (PYR13) based ionic liquids (ILs) with the very same

anions (FSI, TFSI) have here been added; creating ternary polymer electrolytes NaX-PEO-

PYR13X. The resulting ternary systems are compared with the analogous binary systems in terms

of basic physico-chemical properties obtained by dielectric spectroscopy, differential scanning

calorimetry, and Raman spectroscopy. Overall, the addition of ILs to the binary systems increases

their conductivity and the PEO chain mobility. These effects are most likely due to the presence of

the PYR13 cation, which does not interact strongly with the PEO chains, and the contribution of the

different ions is crucial in view of application of ternary systems in SIBs.

References 1. A. Ponrouch et al., Journal of Material Chemistry A 3 (2015) 22 2. V. Palomares et al., Energy & Environmental Science 5 (2012) 5884 3. M. H. Slater et al., Advanced Functional Materials 23 (2013) 947 4. J. W. Fergus, Solid State Ionics 227 (2012) 102 5. A. Ferry et al., Electrochimica Acta 43 (1998) 1387 6. M. Perrier et al., Electrochimica Acta 40 (1995) 2123 7. A. Boschin and P. Johansson, Electrochimica Acta 175 (2015) 124 8. L. Edman et al., Journal of Materials Research 15 (2000) 1950 9. J. H. Shin et al., Electrochemistry Communications 5 (2003) 1016


23

P5

Development of nanostructured thermoelectric materials

Joakim Brorsson*, Richard Heijl**, Anders Palmqvist*

*Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Göteborg,

Sweden; **GKN Aerospace Sweden AB, SE-46181 Trollhättan, Sweden.

ABSTRACT: A thermoelectric generator is composed of two types of legs, made up of n- and p-

doped thermoelectric materials that are connected to a hot zone and a heat sink. Under such

conditions the temperature difference will give rise to an electric potential drop over the two legs,

which, in turn, generates an electric current when the circuit is closed. The maximum efficiency of

such a device, η, is determined by the hot and cold temperatures as well as the so called

thermoelectric figure-of-merit, ZT = σS2T/κ, where σ and κ are the electrical and thermal

conductivities, T is the absolute temperature and S is the Seebeck coefficient. The strong

interdependence between these parameters is the main principle obstacle that must be overcome in

order to develop materials with high values of ZT, which is needed for large scale adaptation of

thermoelectric applications. [1][2]

During the last two decades, several different approaches for lowering 𝜅 and, thus, reaching 𝑍𝑇 >1 have been developed. This includes both nanostructuring as well as focusing on materials that

falls under the “Phonon Glass and Electron Crystal” concept, proposed by Slack. One group of

compounds that satisfy these criteria are the inorganic clathrates, which, characteristically, have

remarkably low thermal conductivities. [3][4]

The overall goal of this proeject is to combine the benefits of nanostructuring with the inherently

good thermoelectric properties of inorganic clathrates. Presently, the main aim has been to produce

compounds made up of a combination of Ba8Ga16Ge30 and Ba8Al16Ge30, with the aim of forming

nanostructured endotaxial precipitates of one phase in the other. Specifically, studies have been

carried out using spark-plasma sintering of powder mixtures as well as by implementing the

Czochralski method for single crystal pulling from a melt. The structural and thermoelectric

properties of the samples thus obtained have been characterised using a range of different

techniques, such as X-ray diffraction, followed by Rietveld refinement, as well as methods for

physical property measurements of 𝜎, 𝜅 and 𝑆.

References

1. Godart C, Gon ̧calves AP, Lopes EB, Villeroy B. Role of Structures on Thermal Conductivity in

Thermoelectric Materials. In: Zlatíc V, Hewson AC, editors. Properties and Applications of

Thermoelectric Materials. NATO Science for Peace and Security Series B: Physics and Biophysics.

Dordrecht, The Netherlands: Springer Science + Business Media B.V.; 2009. p. 19–49

2. Snyder GJ, Toberer ES. Complex thermoelectric materials. Nat Mater. 2008 Feb;7(2):105–114.

Available from: http://dx.doi.org/10.1038/nmat2090

3. Sootsman J, Chung D, Kanatzidis M. New and Old Concepts in Thermoelectric Materials.

Angewandte Chemie International Edition. 2009;48(46):8616–8639. Available from:

http://dx.doi.org/10.1002/anie.200900598

4. Christensen M, Johnsen S, Iversen BB. Thermoelectric clathrates of type I. Dalton Trans.

2010;39(4):978–992. Available from: http://dx.doi.org/10.1039/B916400F

http://dx.doi.org/10.1038/nmat2090

http://dx.doi.org/10.1002/anie.200900598

http://dx.doi.org/10.1039/B916400F


24

P6

Studies of Automotive Catalyst Deactivation

Johanna Carlsson, Per-Anders Carlsson, Magnus Skoglundh

Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96 Göteborg, Sweden

Understanding and preventing catalyst deactivation is crucial for real catalytic processes as to comply

with environmental standards and become economically feasible. This project focuses on deactivation of after treatment catalysts in biogas vehicles.

Representative catalysts will be exposed to relevant hydrothermal and chemical deactivation

conditions and catalytic activity/selectivity of the exposed catalysts will be evaluated alongside

rigorous catalyst characterization. This will be an iterative process to build knowledge about operating deactivation mechanisms.

Deactivation of automotive catalysts progress over prolonged exposure to severe, although not

completely known, reaction conditions. Research and development of more robust catalytic

technologies, however, need methods for precise and accelerated deactivation to advance progress in

reasonable time. Here we construct a reactor in which a series of catalysts is subjected to the same,

well controlled, concentrations of catalyst poisons and relevant temperatures.


25

P7

Cathodic Hydrogen Charging of IN718 – Evaluation and Simulation

Niklas Ehrlin, Christina Bjerkén, Martin Fisk

Materials Science and Applied Mathematics, Faculty of Technology and

Society, Malmö University, SE-205 06 Malmö

In order to study the bulk effect of hydrogen on the tensile properties of a metal, samples have to

be uniformly pre-charged with hydrogen. With the motivation of being less volatile and potentially

result in a higher hydrogen concentration than with autoclave and gas pressure methods, cathodic

charging is a commonly used method [1]. Issues have been raised concerning the potential surface

degradation of the metal because of the cathodic charging, why it is desirable to keep the charging

time as short as possible. Despite this, the literature lacks any extended description of the diffusion

mechanism during the cathodic charging, were diffusion is driven not only by the concentration

gradient of hydrogen, but also by the applied electrical field. If this extra driving force for diffusion

is not considered, the charging time needed is grossly overestimated. In this work, a cathodic

charging procedure [2] of IN718 was performed, evaluated and simulated. The diffusion coefficient

was extended based on electromigration parameters, and used in finite volume simulations to

compute the resulting hydrogen concentration gradient (fig. 1). For reference, computations were

also made for a charging based only on a concentration driven diffusion coefficient. Charged

samples were carefully lathed down to different radius before hydrogen measurement, in order to

evaluate any radial concentration gradient (fig. 2). After compensating for the depth gradient, the

measured results show a homogeneous radial distribution of hydrogen, which confirms that the

extended diffusion coefficient has to be used in any theoretical evaluation of the cathodic charging.

Figure 1: Computed concentration profile Figure 2: Hydrogen concentration measured

for a normal and extended diffusion coefficient. at various radius of the sample.

References:

1. Au, M. (2007). High temperature electrochemical charging of hydrogen and its application in hydrogen

embrittlement research. Materials Science and Engineering: A, 454–455(0), 564-569.

2. Liu, L., Zhai, C., Lu, C., Ding, W., Hirose, A., & Kobayashi, K. F. (2005). Study of the effect of δ

phase on hydrogen embrittlement of inconel 718 by notch tensile tests. Corrosion Science, 47(2), 355-367.


26

P8

Determination of 3D microstructure of different types of coatings for

controlled drug release

C.Fager1*, A.Olsson2, N. Lorén1,3, A.Särkkä4, E.Olsson1

1. Department of Applied Physics, Chalmers University of Technology, SE-41296 Gothenburg Sweden

2.

AstraZeneca R&D Mölndal, SE-43183 Mölndal, Sweden

3. Structure and Material Design, SP Food and Bioscience, Frans Perssons väg 6, SE-40229 Gothenburg, Sweden

4. Department of Mathematical Sciences, Chalmers University of Technology, SE-41296 Gothenburg, Sweden

In controlled drug release is the phase-separated polymer film that covers the drug often made of

two immiscible polymers. A common choice is Ethyl Cellulose (EC), water insoluble cellulose

derivative, mixed with a water soluble cellulose derivative, in this case Hydroxypropyl Cellulose

(HPC). Previous work in this area has been performed at Chalmers by Anna Olsson and co-workers

on in situ wetting experiments concerning different polymer ratios for studying mass transport

through phase-separated EC/HPC films1. The different polymer ratios that has been used in

previous studies are denoted as percentage of HPC in the polymer blend which are as follow;

HPC18, HPC22, HPC30, HPC50 and HPC100. Previous results from the research performed by

Boissier and co-workers on different polymer ratios indicate on a percolation threshold at HPC222.

Below this threshold the HPC is encapsulated in the EC phase thus results in a low film

permeability and above the threshold, HPC form a continuous phase which results in a porous

structure upon contact with water since HPC then leaks out, thus a porous EC matrix remains.

A next step in this research field is to characterise the three dimensional microstructure of the

phase-separated polymer films to be able to increase the understanding regarding the correlation

between microstructure and mass transport even further. It is known that the pore size and the pore

connectivity affects the release properties and therefore this study address quantification of pore

size and a first study to identify a suitable method for determine the connectivity of pores.

As a first attempt to reconstruct the three dimensional pore connectivity, the sample preparation

technique, scanning electron microscope combined with focused ion beam (FIB-SEM) is

considered. Thin layers will be milled away by the ion beam and micrographs obtained at each

layer to reconstruct the microstructure afterwards using a software. An advantage with this sample

preparation technique is that the area to be studied can be carefully selected and the challenging

part will be to adjust the operating parameters to obtain the quality of the micrographs as are

required.

References

1. Jansson, A., Boissier, C., Marucci, M., Nicholas, M., Gustafsson, S., Hermansson, A.-M., Olsson, E.

2014, Novel Method for Visualizing Water Transport Through Phase-Separated Polymer Films. Microscopy

and Microanalysis 20, 394-406.

2. Boissier, C., Feidt, F., Nordstierna, L. 2012, Study of Pharmaceutical Coatings by Means of NMR

Cryoporometry and SEM Image Analysis. Journal of Pharmaceutical Sciences 101 (7), 2512-2522.


27

P9

Extraction and Characterisation of Arabinoxylan from Barley Husk

Linda Härdelin*, Mikaela Börjesson**, Kristina Karlsson***, Anna Ström*, Anette Larsson*,

and Gunnar Westman**

SmartFoam, Formas Project at Chalmers Unversity of Technolgy, SE-412 96 Göteborg, Sweden

*Pharmaceutical Technology at Applied Chemistry, Department of Chemistry and Chemical Engineering,

Chalmers University of Technology, SE-412 96 Göteborg, Sweden

**Organic Chemistry at Chemistry and Biochemistry, Department of Chemistry and Chemical Engineering,

Chalmers University of Technology, SE-412 96 Göteborg, Sweden

***Polymeric Materials and Composites, Department of Materials and Manufacturing Technology, Chalmers

University of Technology, SE-412 96 Göteborg, Sweden

The SmartFoam project is focused on facilitating replacement of fossil-based raw materials with

modified, renewable hemicelluloses, for large scale production of advanced tailored foam

materials. Hemicelluloses are the second most abundant biopolymer in nature. However, the

commercially available hemicelluloses obtained from wood and cereal are still very expensive and

scarce.

Half kilo scale hemicellulose extraction was performed where arabinoxylan was extracted from

milled Barley Husk (Lyckeby Culinar, Sweden). Pre-treatment to remove extractives was done

with 10 litres of 0.05 M HCl. To separate solid material and liquid centrifugation techniques was

used throughout the procedure. pH was adjusted to an optimized pH at 3.1 and lignin was removed

with NaClO2 (15 wt% relative to the starting material) at 80 °C for 3 hours. A reduction reaction

was carried out with a reducing agent (10 wt% relative to the starting material) and 5 litres of 1 M

NaOH. Concentrated HCl was used to neutralize the material and during the neutralization the

cellulose was precipitated. The remaining hemicellulose was precipitated in ethanol at a 2:1 ratio.

From the extraction process 278 g fully dried cellulose were collected, corresponding to a 55.6 %

cellulose yield. After precipitation in 95 % ethanol 127 g fully dried hemicellulose were collected,

corresponding to a 25.4 % hemicellulose yield. The extracted hemicellulose consisted of arabinose

and xylose, and was characterized with regard to molecular weight, radius of gyration, and

carbohydrate composition.


28

P10

Energy efficient water treatment using the blueprint of nature:

Utilizing aquaporins, lipids and mesoporous silica to purify water

Simon Isaksson, Fredrik Höök*, and Martin Andersson

Division of Applied Surface Chemistry, Chalmers University of Technology, *Division of Biological Physics,


INTRODUCTION: The growing population in areas

where fresh water supplies are scarce is resulting in

difficulties satisfying the demands for drinking water.

Pollution and environmental changes are increasing the

demands further. Improvements in water treatment

processes are therefore needed, an issue we suggest to solve

by developing a device that desalinates water using a

biomimetic approach (figure 1).

METHODS: The idea is to desalinate sea water using a

membrane that resembles the membrane of living cells, by

reconstituting aquaporins in a lipid bilayer. Lipid bilayers

are suitable as separation membranes since transmembrane

transporter proteins, such as aquaporins, can readily be

reconstituted to add selectivity, whereas a general

characteristic of lipid bilayers is that they are inert and

impermeable to most substances.

The lipid bilayer is by itself not rigid enough to withstand

the pressures of reverse osmosis processes, which urges the

use of a support that is able to stabilise the bilayer. We are

using a mesostructured support material.

Some of the analysis methods used in the project are QCM-

D, cryo-TEM, TEM, SEM, DLS and fluorescence

microscopy.

RESULTS: We have shown that it is possible to take advantage of the best from both an aperture

spanning and a solid supported lipid bilayer design [1].

It is of great importance to the application that the lipid bilayer is fluid. Using FRAP, we have

shown that the bilayer is fluid, thereby incorporating lipids that are diffusing within the bilayer [1].

DISCUSSION & CONCLUSIONS: We have proved it possible to deposit a fluid lipid bilayer on

a mesoporous support material, thereby providing transmembrane proteins with an aqueous

environment on both sides of the bilayer as well as the necessary mechanical support for the lipid

bilayer.

REFERENCES:

1. M. Wallin, S Svedhem, M. Andersson et al (2011) Langmuir 27:8974-8982.

ACKNOWLEDGEMENTS: The authors acknowledge The Swedish Research council Formas

for the financial support of the project.

FIGURE 1: SCHEMATIC

ILLUSTRATION DEPICTING THE

WATER TREATMENT DEVICE AND

THE WATER TREATMENT PROCESS.


29

P11

3D characterization of rolling contact fatigue crack networks

Casey Jessop, Johan Ahlström, Lars Hammar

Department of Materials and Manufacturing Technology, Chalmers University of Technology, Gothenburg

Rolling contact fatigue (RCF) damage is becoming more frequent with increased traffic,

accelerations, and loading conditions in the railway industry. Defects which are characterized by a

two-lobe darkened surface and a V-shaped surface-breaking crack are defined as squats. The

origination and propagation of squats in railway rails is the topic of many recent studies; the

associated crack networks develop with complicated geometry near the surface of rails, but can be

difficult to detect and distinguish from normally existing head checks in its early stages, using in-

field non-destructive testing. After cutting out damaged sections of rail, there are a number of

options to characterize the damage.

The aim of this study was to evaluate different methods to geometrically describe squat crack

networks; through radiography, metallography, and topography measurements. The experiments

were performed on squats from rail sections taken from field. First, high-resolution and high-

energy X-ray images exposed through the entire rail head from a range of angles were combined

using geometrical reconstruction, and a 3D representation of the complex crack network was

achieved. This was complemented with repeated metallographic sectioning to determine the

accuracy of prediction of the geometrical reconstruction. Another squat was opened after

radiography which gave full access to the crack faces, and topography measurements were

performed.

The high-energy X-ray, 3D reconstruction method showed accurate main crack geometry in the

medium depths; the crack tips were not visible though, due to limitations in radiography in terms

of detecting tightly closed cracks in very thick components. Metallographic investigation of the

cracks gave good interpretation of crack geometry along the sections examined, and gave the

possibility to study microstructure and plastic deformation adjacent to the crack face. Topography

measurements acquired by stylus profilometry provided an accurate description of the entire main

crack surface texture, including features such as surface ridges and beach marks.


30

P12

Foaming of hydroxypropyl methyl cellulose:

Microstructure and mechanical properties

Kristina Karlsson*, Erich Schuster**, Marco Berta**, Mats Stading*,** and Mikael Rigdahl*

*Department of Materials and Manufacturing Technology, Chalmers University of Technology, SE-41296,

Göteborg, Sweden, ** SP Food and Bioscience, SE-40229, Göteborg, Sweden E-mail for correspondence:

[email protected]

The industrial demand for cheap, lightweight, single-use packaging material has led to an extensive

use of fossil based polymeric foams like expanded polystyrene. There are two major drawbacks of

these foamed materials. The first one is that the raw material is coming from a non-renewable

resource and the second one is that the recycling process of these foams can be problematic.

Cellulose is a promising non-fossil based alternative material for foaming applications, as it is

lightweight, abundant and renewable. Cellulose consists of long polysaccharide chains which

varies in length but can be up to 15000 monomer units long. Through various chemical

modifications, the properties of the cellulose can be tailored to suit the application.

Here, hydroxypropyl methylcellulose (HPMC) was used together with water, acting as the blowing

agent, in order to produce foams with a hot-mold foaming technique. The foaming ability of HPMC

was evaluated using different polymer concentrations and foaming temperatures. The produced

HPMC-foams were characterized with regard to their apparent density and by scanning electron

microscopy (SEM) imaging. Additionally, the mechanical properties of the polymer solution

during the foaming were studied using dynamical mechanical testing (DMA), giving insights that

the achievement of a gel-like structure before evaporation of all water is advantageous when

forming regular, stable foams.

The aim of the project is to provide knowledge about alternative and renewable materials and

understand the mechanism of foam formation of those, which hopefully in the future will be able

to replace or reduce the use of fossil-based products.

Figure 1: From left to right: 20:80 w/w% HPMC:H2O, Franz Haas hot-mold machine, foamed HPMC samples, SEM

image of internal pore structure.


31

P13

Bone Inspired Materials

Anand Rajasekharan, Romain Bordes, Martin Andersson

Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden

Introduction: Biomimetic composites inspired from natural bone might pave way to

osseointegrative and regenerative orthopaedic implants. We have synthesized a highly ordered,

structurally anisotropic and three-dimensional (3-D) polymer-hydroxyapatite (HA) composite

inspired from the nanostructure and composition of cortical bone.

Methods: To mimic HA mineralization within collagen fibrils, we used molecular self-assembly

of amphiphilic triblock copolymers and water to form lyotropic liquid crystals (LLC). LLCs are

highly ordered materials that mimic the ordered assembly of collagen fibrils in bone. The LLCs

were covalently crosslinked to form resilient and flexible polymerized liquid crystals (PLCs). Next,

bone-like HA was formed in-situ from respective ions within the nanoscopic aqueous domains of

the PLCs, yielding a composite material with a well-defined nanostructure inspired from bone (see

figure 1A)1.

Figure 1(A) Formation and nanostructure of bone and our biomimetic composite. (B) SAXS

scattering confirms presence of order and anisotropy in composite. (C) TEM image shows

alignment of HA nanocrystals with the PLC

Results: Small angle X-ray scattering (SAXS) data of the nanocomposite confirmed the presence

of meso-ordered (hexagonal) structure with long-range anisotropy of the nanocomposite similar to

bone (Figure 1B)1. Moreover electron microscopy images of grounded composites show alignment

of the HA nanoparticles due to the orientation from the PLC matrix (Figure 1C)1. Mechanically,

the composite showed compressive strength of 3-4 MPa, which is comparable to cancellous bone,

an important result for further developing the implant. Current work focuses on developing the

composite with a 3-D hierarchical structure and a porous network for functioning as a scaffold.

Discussion: In this work, we have used molecular self-assembly of synthetic polymers to form a

mesoscopically ordered polymer-apatite nanocomposite having similar apatite chemistry and a

highly ordered nanostructure inspired from bone.

References:

1. He, W.; Rajasekharan, A. K.; Bagha, A.; Andersson, M., Adv. Mater. 2015, 27, (13), 2260-2264.


32

P14

Novel materials for hybrid super capacitors

Simon Lindberg, Aleksandar Matic


Abstract

Supercapacitors are energy storage units that store charge as nanometer thin layers of ions with

opposite charge at the electrolyte/electrode interfaces. Batteries store the charge electrochemically

in the electrodes. This way a supercapacitor can charge/discharge much faster than traditional

batteries, which results in higher power density but at the cost of lower energy density.1 The energy

density also depends on the square of the operating voltage, so it can be increased by using

materials that resists higher voltage. Another way to improve the energy density is by adding

surface-active materials that can change oxidation number and in the process contribute with higher

charge density; this class of supercapacitors are called hybrids.2

Hybrid-supercapacitors with different electrochemically active materials

have been thoroughly researched, but mostly with aqueous electrolytes. A

promising candidate to replace the aqueous electrolytes are ionic liquids,

but their performance are still worse than aqueous. My research question

focuses on how to improve the performance of these; which properties are

important? Which additives should be used and how will it affect the

operating voltage and general performance?

MnO2 has been used as the active material in the measurements presented,

aqueous and ionic liquids with added salts as electrolytes. The synthesized

MnO2 material has an energy density of 7 Wh/kg, power density of 300

W/kg and specific capacitance of 45 F/g. The energy density of the full

cell with ionic liquid electrolyte is increased (Figure 2) due to higher

voltage. But the capacitance is reduced from 24 to 17 F/g, which can be

seen in Figure 3 as a lower current.

Figure 2 & 3, Energy density, aqueous and ionic liquid electrolytes compared (left). Cyclic voltammetry plots (right)

References

1. Conway, B. E. Electrochemical Supercapacitors: Scientific Fundamentals and Technological

Applications (Kluwer, 1999)

2. Simon, P. and Y. Gogotsi (2008). "Materials for electrochemical capacitors." Nature Materials 7(11):

845-854.

Figure 2, Ragone plot2,

showing how different battery

types perform. the dashed line

indicates how long a cell with

a specific energy content can

run with the corresponding

power.


33

P15

Ageing of RPV steel – an atom probe tomography study

Kristina Lindgren, Krystyna Stiller, Mattias Thuvander

Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden

Reactor pressure vessel (RPV) steels are a life-limiting component of a nuclear reactor. Neutron

radiation during operation makes the steel embritteled, the higher dose the larger effect. This is

important to consider when looking at prolonging the operational time of a reactor. Since the

microstructural changes during irradiation are on a very small scale (i e nanometre precipitates)

atom probe tomography (APT) is a suitable technique for investigation of the neutron radiation

effect. Using APT it is possible to map the position of atoms in 3D in a small volume.


34

P16

Modification of galactoglucomannans for development of

interpenetrating networks

Kajsa Markstedt*, Chunlin Xu**, Paul Gatenholm*

* Wallenberg Wood Science Center. Biopolymer technology, Department of Chemistry and Chemical Engineering,

Chalmers. ** Laboratory of wood and paper chemistry, Åbo Akademi University

Cellulose and hemicellulose are the most abundant bio-macromolecules found in nature and they

constitute a renewable and biodegradable resource with great potential [Klemm 2011] as building

blocks for future materials. In this work I’ve focused on obtaining gelling properties of

hemicelluloses which is an important property for the development of materials used for cosmetics,

drug delivery, food additives, and as bioinks for 3D bioprinting. In nature, cellulose materials are

assembled into nanofibrils and coated with hemicelluloses into cell wall material followed by

physical and chemical crosslinking of lignin to preserve the structure of wood. Tyramine can be

seen as a model compound of lignin being that they both have phenolic groups. In combination

with hemicellulose it acts as a model for the lignin carbohydrate complex. Enzymatic crosslinking

of xylan functionalized with tyramine has been shown to form hydrogels that can be used for cell

immobilization. In this study o-acetyl galactoglucomannan from spruce, GGM, has been

functionalized by tyramine. Carboxylic groups necessary for the tyramine conjugation to take place

were introduced to GGM by TEMPO mediated oxidation. Having a series of GGM with different

degrees of oxidation resulted in GGM-tyramine conjugates with a variety in degree of substitution.

Gelling of GGM-tyramine after addition of horse

radish peroxidase, HRP, and H2O2.


35

P17

Characterization of microstructural changes in railway wheel steels

using orientation imaging microscopy

D Nikas and J Ahlström

Department of Materials and Manufacturing Technology, Chalmers University of Technology, SE-412 96 Gothenburg,

Sweden

Abstract. The focus of this study is the degradation of a near pearlitic microstructure of a railway

wheel under combined mechanical and thermal loadings leading to changes in mechanical

properties. More specifically, it is examined how the orientation gradients inside the pearlite

colonies, affect the spheroidisation. Samples were extracted from virgin near pearlitic railway

wheels and pre-strained, thereafter heat treated at different temperatures. Microstructural

characterization by scanning electron microscopy (SEM) and Electron Backscatter Diffraction

Analysis (EBSD) was performed and evaluated. Results showed that spheroidised areas appear to

have lost their initial orientation gradients after spheroidisation and obtain a more uniform

orientation. More sub-grain boundaries are present after exposure to higher temperatures.


36

P18

Plasmonic Nanospectroscopy Sheds Lights on the Properties of

Materials for Energy Applications

Ferry A. A. Nugroho*, Camilla Lindqvist**, Amaia Diaz de Zerio Mendaza**, Chao Xu***,

Niklas Hedin***, Christian Müller** Christoph Langhammer*

*Department of Applied Physics and **Department of Chemistry and Chemical Engineering, Chalmers University

of Technology SE-412 96, Göteborg, Sweden.

***Department of Materials and Environmental Chemistry, Berzelii Center EXSELENT on Porous Materials,

Arrhenius Laboratory, Stockholm University, SE-106 91, Stockholm, Sweden.

The optical indirect nanoplasmonic sensing (INPS)1 platform has established itself as a powerful

and versatile experimental tool to study functional materials at the nanoscale. Its merits include

superior sensitivity down to individual nanoparticles,2 possibility for in situ and in operando

experiments under a wide range of conditions, flexibility in terms of the studied sample materials,

and a relatively simple setup. In this work we demonstrate how INPS can be used to characterize

key descriptors of polymer materials for energy applications.

The first study constitutes the determination of the thickness dependent glass transition

temperature, Tg, in a polymer solar cell blend.3 The blend consists of fullerene acceptors, PC61BM

and PC71BM, and a TQ1 donor. Here, for the first time, we reveal that the Tg of the blend lies in

between the Tg of its individual components. Furthermore the result also promises a higher thermal

stability for thin (i.e. < 100 nm) bulk-heterojunction materials.

In the second study we show how INPS can be an attractive alternative to characterize the gas

adsorption process in a microporous polymer. Specifically, we show how the CO2 isosteric heat of

adsorption (Qst) of microporous PIM-1 polymer can be conveniently obtained without any

calibration; as opposed to the conventional methods. This study in general provides a general

blueprint for efficient optical screening of micro- and mesoporous polymeric materials for Carbon

Capture and Storage (CCS) or other CO2/gas separation processes in terms of their adsorption

energetics and kinetics.4

References

1. Langhammer, C.; Larsson, E. M.; Kasemo, B.; Zorić, I. Indirect Nanoplasmonic Sensing: Ultrasensitive

Experimental Platform for Nanomaterials Science and Optical Nanocalorimetry. Nano Lett. 2010, 10, 3529–3538.

2. Syrenova, S.; Wadell, C.; Nugroho, F. A. A.; Gschneidtner, T. A.; Diaz Fernandez, Y. A.; Nalin, G.; Świtlik, D.;

Westerlund, F.; Antosiewicz, T. J.; Zhdanov, V. P.; et al. Hydride Formation Thermodynamics and Hysteresis in

Individual Pd Nanocrystals with Different Size and Shape. Nat. Mater. 2015, doi:10.1038/nmat4409.

3. Nugroho, F. A. A.; Linqvist, C.; Diaz de Zerio Mendaza, A.; Müller, C.; Langhammer, C. Plasmonic

Nanospectroscopy Sheds Light on the Thermal Stability of a Polymer Solar Cell Blend. Submitted. 2015.

4. Nugroho, F. A. A.; Xu, C.; Hedin, N.; Langhammer, C. UV-Vis and Plasmonic Nano-Spectroscopy of the CO2

Adsorption Energetics in Microporous Polymers. Anal. Chem. 2015, doi:10.1021/acs.analchem.5b03108.


37

P19

Bacterial biofilm elimination using localised surface plasmon

resonance generated heat

Maria Pihl, Mats Hulander, Martin Anderson

Applied Surface Chemistry, Chalmers University of Technology, Sweden

In 2009, 566 million dollars were spent in the US health care system to treat 22000 infected hip

and knee implants, and these figures are increasing due to an aging population. Up to 3% of the

affected patients die of their infection, but for older patients the mortality rate is even higher. The

need to find new ways of treating implant related infections is thus urgent.

When illuminating gold nanorods with light of a certain frequency localised surface plasmon

resonance occur and when the plasmon relax, heat is generated. This heat we use to eliminate

bacterial biofilms.

Citrate stabilised gold nanorods (Nanopartz inc, Loveland, USA) were attached to glass surfaces

by silanisation and studied in scanning electron microscopy for surface coverage. Staphylococcus

epidermidis was cultured planktonically to mid logarithmic phase, washed and allowed to form

biofilms on the gold nanorod coated surfaces. Then the surfaces were illuminated by NIR light,

and bacteria were studied in fluorescence microscope using LIVE/DEAD BacLight staining.

The SEM images showed the surfaces to be evenly coated with gold nanorods and the LIVE/DEAD

staining after NIR illumination showed the majority of bacteria to be dead. The results indicate the

possibility of eliminating biofilms using plasmon generated heat and has potential in future

antimicrobial implant applications.

Glass surfaces were coated with gold nanorods and studied in SEM, and then S. epidermidis biofilms were allowed to

form. After IR irradiation, biofilms were stained with LIVE/DEAD Baclight and the majority of bacteria were dead

(red) as compared to the control samples not IR irradiated where most bacteria were alive (green).


38

P20

A swallowing model for efficient food product development

Waqas Muhammad Qazi1,2, Johan Wiklund1, Olle Ekberg3 and Mats Stading1,2

1SP Food and Bioscience, Soft Materials Science, 402 29 Gothenburg, Sweden

2Chalmers University of Technology, Materials and Manufacturing Technology, 412 96 Gothenburg, Sweden

3Diagnostic Centre of Imaging and Functional Medicine, Skåne University Hospital, Lund University, 205 02

Malmö, Sweden

Dysphagia refers to difficulties in swallowing, caused by conditions ranging from trauma to

neurological disorders such as dementia. People suffering from dysphagia cannot adequately

transfer food from the mouth to the stomach especially low viscosity, fluid foods. Texture

modification is imperative to ensure safe passage of food from mouth into the stomach. Food

products with elastic properties, i.e. high extensional viscosity, have been identified as helpful in

promoting safe swallowing. However, this hypothesis is difficult to prove by clinical studies due

to ethical issues and availability of suitable patients. Moreover, the problems of individual patients

vary largely in nature and extent which further complicates the matter as identified in our previous

research (1).

We are currently constructing an in vitro human swallowing apparatus mimicking swallowing

through the pharynx to the esophagus. The apparatus will have the pressure and ultrasound sensors

to monitor real time flow properties of the bolus as it travels along the swallowing tract. This will

enable us to measure relevant parameters during swallowing such as residence times and bolus

velocity along the way. The model can be adjusted to different dysphagic conditions such as

abnormal epiglottis closure.

The goal of the project is to develop food products for safe swallowing and currently we are

determining the rheological properties of commercial dysphagia thickeners, as well as model fluids.

Two companies active in dysphagia foods are contributing (Fresenius Kabi and Findus). The shear

and extensional properties have been shown to vary significantly, which has been correlated with

fluid microstructure.

References

1. Nystrom M. et al. 2015. Waqas Muhammad, Margareta Bulow, Olle Ekberg, Mats Stading

Effects of rheological factors on perceived ease of swallowing. Appl. Rheol. 25:6


39

P21

Defect formation during laser welding and their effect on

mechanical properties of Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo

Sakari Tolvanen

Chalmers University of Technology, Department of Materials and Manufacturing

The main objective of this project is to explain why pores and other defects are formed for certain

weld parameters for different welding processes. Laser welding is the dominating welding process

for fabrication of larger aero engine structures and is therefore the main welding process in focus

for this project. Because not all types of defects affect the mechanical properties, it is also important

to understand how to distinguish between defects that are detrimental to properties and those that

are not. In addition, the effect of weld geometry with regard to mechanical properties will also be

explored. The project will focus on the titanium alloys Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo, the

two most commonly used titanium alloys at GKN Aerospace.


40

P22

Understanding the Inhibiting Effect of Water on Methane Oxidation

Catalysts

Peter Velina, Per-Anders Carlssona, Magnus Skoglundha, Gudmund Smedlerb, Agnes Rajc

aCompetence Centre for Catalysis, Chalmers University of Technology, SE-412 96 Göteborg, Sweden bJohnson Matthey AB, Victor Hasselblads Gata 8, SE-431 21 Västra Frölunda, Sweden

cJohnsson Matthey, Blounts Court Road, Sonning Common, Reading RG4 9NH, UK

To reduce the environmental impact of future transports, a considerable share of the fossil fuels

should be replaced by renewable alternatives. An interesting candidate fuel is biogas, which during

combustion delivers more power per released carbon dioxide as well as low emissions of NOx, SOx

and particulates compared to diesel and petrol [1]. However, methane, the main component of

biogas, has about 80 times higher global warming potential (GWP) than carbon dioxide over a

twenty-year period [2]. Thus careful control of methane emissions to low levels is necessary.

A well known challenge with catalytic methane oxidation is the initial dissociative adsorption step

where the stable tetrahedral methane molecule is transformed into hydrogen and methoxy (CHx)

adsorbates. Previous studies have also stated that the presence of water in the exhaust gas

significantly lowers the catalytic activity for methane oxidation over traditionally used catalysts.

The main objective of this study is to increase the fundamental understanding of alumina supported

palladium catalysts during catalytic oxidation of biogas components, specifically addressing the

detrimental effect of water. A bottom-up research approach, see figure 1 will be developed and

used to study single catalyst components and catalyst models of varying complexity. In-situ

DRIFTS and XAFS analysis with subsequent MS activity measurements will mainly be used. The

outcome will lead to design of new high-performance catalysts for biogas aftertreatment systems

with increased tolerance towards water.

References 1. P. Gelin, M. Primet, Appl. Catal. B 39 (2002) 1.

2. T.F., D. Qin, G.-K. Plattner, M. Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex and P.M. Midgley

(eds.). Anthropogenic and Natural Radiative Forcing Cambridge University, UK and NY, USA.


41

P23

High-Entropy Alloys (HEAs)--Alloyed pleasures or

Multimetallic cocktails

Saad Sheikh ([email protected]), Dr. Sheng Guo ([email protected])


Abstract:

This project is devoted to studying the alloy development and mechanical property of high-entropy

alloys. High-entropy alloy (HEAs), or multi-component alloys with equiatomic or close-to-

equiatomic compositions, emerge as novel metallic materials with great potential to be used as high

temperature materials, or coating materials requiring high hardness and high wear resistance.

Although being highly concentrated multi-component alloy systems, simple solid solutions tend to

form in HEAs, with the absence of intermetallic compounds. This seemingly unexpected

phenomenon is partly due to the significant entropic contribution, which lowers the Gibbs energy

of the solid solution phases at elevated temperatures. Normally, the formed solid solutions in HEAs

are of fcc and/or bcc structures. The mechanical behaviour of HEAs are greatly affected by the

phase constitutions. How to simultaneously achieve both high strength and high tensile ductility is

a great challenge in the field. It mainly involves alloy development and thermomechanical

treatments, to tune the phase constitution and the microstructure, aiming at obtaining novel HEAs

with balanced strength and tensile ductility.


42

P24

Direct Conversion of Methane to Methanol (DCMM) over Cu-

Exchanged Zeolites

Xueting Wang, Magnus Skoglundh, Anders Hellman, Johan Gustafson*, Per-Anders Carlsson

Competence Centre for Catalysis, Chalmers University of Technology, Göteborg, Sweden

*Division of Synchrotron Radiation Research, Lund University, Lund, Sweden

Abstract. Direct conversion of methane to methanol is a potential alternative process for efficient

production of methanol, which has been inspired by the unique functionality of methane

monoxygenase, which is an enzyme that can selectively oxidize methane to methanol under

ambient conditions. Recently, a range of metal-zeolites have been prepared and shown to be active

for DCMM under mild conditions as compared to the industrial syngas process. Amongst these

zeolitic materials, Cu-exchanged zeolites have shown to be surprisingly active for DCMM when

using molecular oxygen as the oxidant. Previous studies have identified the active sites for DCMM

in Cu-ZSM-5 as a bent mono-(μ-oxo)dicupric site, which has been associated to an adsorption band

at 22,700 cm-1 in the ultraviolet-Visible (UV-Vis) spectrum.[1, 2] Comparable activities have also

been observed for Cu-mordenite and Cu-chabazite, suggesting that the bent mono-(μ-oxo)dicupric

site may not be the only type of Cu site that is active for DCMM.[3-5] Furthermore, zeolites

exchanged with other metals (e.g. Fe, Co) have also demonstrated activity for DCMM. Recent

studies have focused on identifying the active site and operation mechanism; however, significant

challenges remain that need to be addressed, such as the regeneration of the active sites at low

temperatures and extraction of the formed product from within the zeolites pores.

In this study, a series of metal-exchanged zeolites were prepared by aqueous ionexchange.[6] The

powder samples were characterized by scanning electron microscopy (SEM), X-ray diffraction

(XRD), UV-Vis spectroscopy and reflectance infrared Fourier transform spectroscopy (DRIFTS).

The catalytic activity of monolith samples was tested using a continuous gas-flow reactor with

outlet gas analysed by mass spectrometer (MS).

Although the activity for DCMM reaction at present is minor, the results are interesting as Cu ions

could be introduced in the pores of the zeolite with preserved zeolite structure. Despite the fact that

a complete catalytic cycle is likely not operating, these results are encouraging for future studies.

References

1. J. S. Woertink, P. J. Smeets, et al., Proceedings of the National Academy of Sciences of the United

States of America, 106 (2009)

2. P. J. Smeets, R. G. Hadt, et al., Jounal of the American Chemical Society, 132 (2010)

3. S. Grundner, M. A. C. Markovits, et al., Nature Communications, 6 (2015)

4. E. M. C. Alayon, M. Nachtegaal, et al., Physcal Chemistry Chemical Physics, 17 (2015)

5. M. J. Wulfers, S. Teketel, et al., Chemical Communications, 51 (2015)

6. N. V. Beznis, B. M. Weckhuysen, et al., Catalysis Letters, 138 (2010)


43

P25

Enzyme Immobilization in Modified Mesoporous Silica for CO2

Reduction

Milene Zezzi do Valle Gomes , Anders Palmqvist


The utilization of atmospheric CO2 to synthesize methanol can represent an efficient way to

recycling the greenhouse gas. However CO2 is a very stable molecule and its conversion to

methanol demands excessive energy and remains a challenge. Thus, biocatalysis appears as a very

interesting and competitive method to reduce CO2 due to the high efficiency and selectivity of

enzymes in mild conditions.

The enzymatic catalysis of CO2 to produce methanol requires the use of 3 enzymes: formate-,

formaldehyde- and alcohol dehydrogenase. The immobilization of enzymes enhances their stability

and reusability. Siliceous mesostructured cellular foams (MCF) is a very attractive material to

support those enzymes, due to its large pore size and surface area. Moreover the surface of MCF

can be easily modified with organic functional groups in order to enhance the interaction with the

enzymes.

In this work MCF with suitable pore size was synthesized and its surface was modified with

aminopropyl, mercaptopropyl, octyl and chloromethyl groups and their interactions with the

enzymes were evaluated in terms of maximum pore loading. For all the enzymes it was observed

a very high pore loading (more than 200mg of enzyme/g of support) in MCF and MCF

functionalized with mercaptopropyl, octyl and chloromethyl groups. Formate- and formaldehyde

dehydrogenase showed higher interaction with the modified MCFs, whereas alcohol

dehydrogenase interacts more strongly with MCF without functional groups in the surface.

Our research has therefore shown that MCFs are very good support for these enzymes and has high

potential to be used in order to improve the use of these biocatalysts.

The Materials Science Graduate Student Days 2016 · 2016-02-18 · 11.20 - 11.40 High pressure jet...

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