Fabrication of PDMS/PVDF nanoporous composite membrane

In this study, a novel nanoporous (mesoporous) membrane with composite structure was fabricated by coatingpoly dimethyl siloxane (PDMS) on the surface of poly vinylidene fluoride (PVDF) microfiltration membrane. The MFPVDF support pore size was about 0.4 micron and after coating with PDMS, the pore size decreased to nanometric scale.The membrane microstructure was characterized using SEM, AFM and gas permeation measurement. The SEM imagedemonstrated that a uniform PDMS thin layer was formed on PVDF support. The AFM image was used to evaluate theprepared membrane surface topology, showing a smooth surface for PDMS coated PVDF membrane. This result wasconfirmed with height line profile obtained from AFM analysis. Also the line profile was used to determine pore size ofmembrane. The gas permeation results showed that the membrane permeation follow Knudsen mechanism, which isexpected mechanism for pores in nanometric scale.

Keywords:

Nanoporous membrane , PVDF support , PDMS layer , Nanometeric pores