Polyvinylidene fluoride membranes porous

A modification of SPE was reported, using a porous membrane made of polyvinylidene fluoride polymer deposited with thin porous Au filin. CO2 was reduced to CO with the faradaic efficiency 75% at the partial current density 20 mA cm as estimated from the difference of the two currents measured under argon and CO2 atmospheres separately. 

Polymeric membranes are monolithic, continuously porous materials. Membranes can be produced from numerous organic polymers including polyalkanes (polyethylene and polypropylene) and their fluorinated derivatives [polyvinylidene fluoride and polytetrafluoroethylene (PTFE)]. Once formed, a membrane can be chemically functionalized by a number of methods including direct conversion of functional groups in the bulk polymer, coating of the surface with a preformed polymer, or graft copolymerization of reactive monomers onto the membrane surface. 

D. Grandine, II (Millipore) Processes of making a porous membrane material from polyvinylidene fluoride, and products. US Patent 4203848, May 1980. 

The membranes used for MD processes are hydrophobic, porous barriers made from PTFE polypropylene (PP) or polyvinylidene fluoride (PVDF). All modifications lead to an increase in the membrane hydrophobicity in order to avoid membrane wettability, thereby making the membrane useful for longtime operation. 

Flat porous poly(vinylidene fluoride) hydrophobic membranes were used for the removal and the recovery of CO2 from the emission sources (Lin et al. 2009b). Methane plasma treatment enhanced the hydrophobicity of this polymer—the elemental F/C ratio at the surface increased and was almost twice as big as the starting value. The water contact angle increased from 132° for virgin polyvinylidene fluoride (PVDF) to 155° after plasma treatment. Some effects of etching were observed, especially for longer plasma treatment time. 

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