Recerca en electro-hidrodinamica i nano-fluidica*

Joan Rosell

FeT group; DEQ; ETSEQ

*Please read notes (in English and Catalan) while reviewing this file

100 nm

Capillary tube held at high voltage

Taylor cone

(liquid meniscus)

Micro-jet

Electrospray

close-up of cone-jet tip

0.1mM LiCl in ethylene glycol

( Fdez.de la Mora et al, J. Fluid Mech 260:155-184, 1994 )

>> Electro-hydrodynamic cone-jets

Liquid flow

“…the diameter is less than 3 nm”

G. Benassayag, P. Sudraud, B. Jouffrey, Ultramicroscopy 16: 1-8, 1985

Gomez and Tang, Phys Fluids 6: 404-414, 1994

Steady cone-jet

Volatile spray

Coulomb explosion

Cytochrome C by ESI-MS

J. B. Fenn, M. Mann, C. K. Meng. S. F. Wong, C. M. Whitehouse, "Electrospray Ionization for Mass Spectrometry of Large Biomolecules," Science 246, 64 (1989).

Solution Viscosity,Kg/m·s

Electricconductivity,

ž -1m-1

Time betweenframes,

s

Glycerol 1.49 2.0x10-6 1/30

5%wt PEG–5M inbenzyl alcohol

> glycerol 5.5x10-6 1/30

1.5%wt PEG–.6Min benzyl alcohol

< but similarto glycerol

5.3x10-6 1/10

>> Motion studies of electrified drops - results summary

End plate

Droplet

H.V.power supply

Oscilloscope

Time (1/30 s)

Sealed capillary

Time (1/10 s)

Electrospinning

PVA

HVDC

Syringe Pump

High voltage DC supply

Syringe Needle

Rotating and Translating

--Courtesy of D. Zhan (Gary E. Wnek)--

Kenawy et al., Biomaterials, 24, 907-913 (2003)

0

1

2

3

4

5

6

7

8

0 5 10 15 20 25

Concentration (w/v %)

Ave

rag

e F

iber

Dia

met

er, M

icro

ns

Fibroblast cells interacting with the EVOH mat after 7 days in culture.

EVOH - poly(ethylene-co-vinyl alcohol) --Courtesy of D. Zhan (Gary E. Wnek)--

>> General scope - ICREA proposal

• Development of aerosol techniques for the generation of nano-structured materials, with emphasis on EHD micro-flows.

• Nano-structured fibrous materials by electro-spinning (ESP)

• Colloid thrusters for micro-satellites

• Electro-hydrodynamics, Electro-hydrodynamic instability of liquids, Rayleigh breakup of droplets, Electrospray ion formation

>> Marie Curie Int’l Grant

Nano-electro-hydrodynamic flows generating droplets

– Projecte europeu– En vies de co-finançament– Inicia la recerca a Catalunya en aquest camp– Mètodes:

• experimentals (mesures de ogtes) COMBINATS AMB la computació d’aquests “nano-fluxos” invisibles

Investigadors

Joan Rosell, (PI), investigador ICREAJoan Herrero, professor titularDolors Puigjaner; professora titularFrancesc Giralt, catedràticDolors Salvatierra, investigadora Ramon y CajalSergi Paredes, Becari