GRADIENT CARBON COMPOSITE MATERIALS FOR HYDROAGEN PROCESSING TECHNOLOGIES

Consideration is given to the state of the art in the production of materials of carbon felt-based gas diff usion layers. It is shown that the nature of a hydrophobic polymer (polyvinylidene-fl uoride, PVDF, and polytetrafl uorethylene, PTFE) has no crucial eff ect on the water contact angle (limiting wetting angle), however, it is of fundamental signifi cance in terms of regulation of the macroporous structure and surface electrical resistance of the obtained materials. Thus, polytetrafl uorethylene concentrates predominantly in the near-surface layers while polyvinylidenefl uoride spreads uniformly through the thickness of the carbon support. Furthermore, the concentration of an impregnating solution of PTFE (fl uorine plastic) suspension makes it possible to regulate effi ciently the surface properties of felts, which can be directly used in the development of gas diff usion layers of fuel cells. On the whole, the use of viscose fi ber-based carbon felts allows the production of gas diff usion materials with a level of surface electrical resistance below 1 Ω/m₂ .
Consideration is given to the state of the art in the production of materials of carbon felt-based gas diff usion layers. It is shown that the nature of a hydrophobic polymer (polyvinylidene-fl uoride, PVDF, and polytetrafl uorethylene, PTFE) has no crucial eff ect on the water contact angle (limiting wetting angle), however, it is of fundamental signifi cance in terms of regulation of the macroporous structure and surface electrical resistance of the obtained materials. Thus, polytetrafl uorethylene concentrates predominantly in the near-surface layers while polyvinylidenefl uoride spreads uniformly through the thickness of the carbon support. Furthermore, the concentration of an impregnating solution of PTFE (fl uorine plastic) suspension makes it possible to regulate effi ciently the surface properties of felts, which can be directly used in the development of gas diff usion layers of fuel cells. On the whole, the use of viscose fi ber-based carbon felts allows the production of gas diff usion materials with a level of surface electrical resistance below 1 Ω/m₂ .
Author:  E. A. Danilov, A. B. Shakhnazarova, O. N. Volkova, D. S. Krisova, V. M. Samoilov, A. R. Gareev
Keywords:  gas diff usion layer, carbon felt cloth, hydrophobization, porosity, electrical conductivity, fuel cell
Page:  1526