Abstract: Fluid diffusion layers with favorable mechanical, physical and structural properties are prepared for fuel cell electrodes by: impregnating a porous carbonaceous web with a matrix comprising a polymer having pyrrolidone functionality and a high carbon char yield resin, such as activated aramid fiber pulp, lignins, phenolics, benzoxazines and phthalonitriles; and carbonizing the matrix. The polymer is optionally oxidized before carbonizing. The matrix may also include conductive fillers and/or pore formers. The fluid diffusion layers are particularly suitable for use in continuous roll-to-roll MEA processing of GDLs for use in solid polymer electrolyte fuel cells operating at high current densities and/or in highly humidified conditions.

Abstract: Carbon-composite materials can be useful for a wide range of applications such as in friction applications as found in automotive continuous slip service in torque converter clutches. Carbon-composites may also be used as fluid diffusion layers in electrochemical fuel cells. Continuous processing of such carbon composites, though long found to be difficult due to unacceptably long dwell times can be done with the use of propane as the hydrocarbon gas, particularly when done at temperatures between 1200 and 2000° C. and 0.1 and 1 mm Hg. In particular, such methods lead to carbon composites with suitable frictional properties.

Abstract: An improved clutch or brake device in which at least two members are mounted for relative rotation and engagement, the members having friction material rotatable therewith, and the friction material of the members having surfaces confronting each other, characterized in that the friction material has a solid density of greater than 30% and includes an open lattice of carbon ligaments forming a network of three dimensionally interconnected cells; and a pyrolytic carbon coating on the open lattice of carbon ligaments.