How does Polytetrafluoroethylene (Teflon) differ from Polyvinylidene fluoride (PVDF) as a protein binding membrane material? PTFE and PVDF (durapore) are both used in protein binding filter membranes (Millipore specifically). Chemically speaking the two polymers differ quite significantly due to the additional fluorides and molecular weight. Their protein-binding properties also differ. I'm curious about how the chemical differences affect their properties as a membrane material.
From what I understand, the durability between the two is quite different. The PTFE membranes are used for the filtration of organic solvents where as the PVDF membranes are generally for low protein binding. Furthermore the PTFE membranes typically require a polyethylene support.
I don't believe that the degree of polymerization or the architecture; if we were dealing with a copolymer I expect differently. Based on my molecular intuition, I would imagine that this is completely based on the chemistry of repeat unit.
My question concerns a few things. What makes the PTFE a better solvent resistant polymer? The other is how does the reduced number of fluroides result in reduced protein binding?

Teflon/PTFE

PVDF
Essentially you are asking why about the different surface properties of PTFE vs. PVDF.  Generally PTFE is more 'non stick' than PVDF, which is more non-stick than polyethene (PE).  PTFE is much more chemically resistant to corrosion than PVDF or PE.  You are correct to look at the chemical structure.  The more Fluorine atoms on the backbone, the more proteins will not be able to chemically latch onto the surface.  Measuring things like contact angle will confirm this.  I don't know how much the pore structure of the membranes affect things, but from a chemical standpoint, there are clear differences.