Whatman Puradisc Syringe Filters – PTFE. membrane materials: regenerated cellulose (RC), cellulose nitrate, nylon, polytetrafluoroethylene (PTFE), polyethersulfone (PES), polypropylene, polyvinylidene difluoride (PVDF), and cellulose acetate. Cytiva Whatman Puradisc line is a comprehensive syringe filter portfolio used in a variety.