Functional Coatings on Steel in the Built Environment -Current and Future Technologies
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Transcript of Functional Coatings on Steel in the Built Environment -Current and Future Technologies
Functional Coatings on Steel in the Built Environment-Current and Future Technologies
Dr Sanjay GhoshResearch [email protected] University
Functional coating is all about material that do things
Application of Functional Coating on Steel
Energy efficiency1. Photovoltaic electricity generation2. Solar heating3. Electroluminescent display
Healthcare and safety1. Intumescent coating for fire protection2. Anti-microbial coating for health
Key area :
Intumescent Coating on Exposed Structural Steelwork Festival Place, Basingstoke and City Point, London (Leigh’s Paints)1. Corrosion resistance paint
Weather Protection
Solar Cell Fabrication on Low Cost Rough Steel Surface
0.3mm
400nm200nm
2.5-3mm
400nm500nm
Organic photovoltaic (OPV) Amorphous silicon solar cell (a-Si:H)
Functional coating: SU8 compatible for OPV, Sol-gel, SiOx compatible for a-Si:H & OPV
PCE = 3%
PCE = 6%
Sol. Energy Mater. Sol. Cell 2016, 157, 305 Sol. Energy 2016, 124, 216
Characterisation of Steel + Functional coating (IL) for PV
Leakage current
For solar applications : Ra~0.03μm, Rz~0.3μm
Steel (Roughness high) Steel +IL (Roughness low)
Functional coating
Steel +
IL
Electrical insulation
Diffusion barrier
Mechanical & Thermal stability
Surface leveling
Pencil method
4
Sol-gel (SiOx) Formulation and Development
SiOx mix = Tetraethylorthosilicate (TEOS) + Methyltriethoxysilane (MTES) + Polyethylene Glycole (PEG) + HNO3 + H2O
SiOx coating is compatible with both vacuum and non vacuum deposition method
Spray coat, bar coat, PVD deposition
Temperature of curing = 100 -300 oC for PV application
SU8 (IL) Formulation and Development
Gamma Butyrolactone) 22-60%
Mixed Triarylsulfonium/ Hexafluoroantimonate Salt 1-2%
Propylene Carbonate
Epoxy Resin (Formaldehyde, polymer with 2-(chloromethyl)oxirane and 4,4'-(1-methylethylidene)bis[phenol])
35-75%
Volume
1-5%
Substrate (steel)
cleaning
coat (K-bar)
Soft bake,
125 -150 oC,
10 min
Develop, 15 min
Hard bake,
230-250 oC,
15 min
SU8 Mix
Processing steps
Surface coverage = 70 g/m2, 60 um thickness film, Bar coat
Economic Viability of Low Carbon Steel + IL as substrate for PV
Cost Steel + ILs should be below 0.175 €/Wp for PV
Annu. Rev. Mater. Res. 2011, 41, 297Sol. Energy 2016, 124, 216
Solar Heater
Ren. Sus. Energy Rev. 2016, 58, 574
Evacuated-tube Solar Collector (Riomay)
Evacuated-tube Solar Collector (Espionoza Energy)
Fe2O3/Stainless Steel at Different temperature
High Temperature Solar Absorber on Steel
Author Coat Technique Absorptanceα
Emittance ε
Remarks
Ambriosini et al. 2010
FeCo2O4
NiCo2O4
Spin coat 0.880.82
0.590.46
Thermal stability above 600 oC
Liu et al. 2012
NbTiON/SiON Magnetronsputtering
0.95 0.07 Thermal stability above 500 oC
Valleti et al. 2014
TiAlCrN/TiAlN/AlSiN Cathodic arcPVD
0.91 0.07 Degrade at high temperature
Cespedes et al.2014
Mo-Si3N4 Magnetronsputtering
0.93 0.02 Potential to be used for CSP
Liu et al.2014
Cr-Al-O Cathodic arc ion plating
0.92 0.21 Suitable for collector at higher temperature
Liu et al. 2017
TiC-WCTiC-WC/Al2O3
Magnetronsputtering
0.780.92
0.110.11
Stable up to 500 oC
Wu et al. 2017
Fe2O3 Thermal oxidation
0.91 0.18 Stable up to 900 oC
Future Trend of Functional Coatings
Example: Acronal® Pro 7600 - latest innovation for corrosion protection for industrial metal coatings presented at the European Coatings Show this month.
Conventional to sustainable technology-water based environmental friendly
With VOC regulations at 50 g/L and below,
Self healing, self cleaning properties, sensing abilities, etc.
April 2017, Germany Chem. Mater., 2010, 22 , 4406
Anti-corrosion paint (BASF)