Preparation of superhydrophobic composite nano-fiber membranes by electrospinning polyacrylonitrile/polydimethylsiloxane

Superhydrophobicity property of the membrane surface diminishes interaction between the contaminations and membrane surface. This causes a reduction in the fouling tendency and self-cleaning characteristic. There are two basic strategies to increase the contact angle and formation of more hydrophobic surface. One is to increase the surface roughness, which is known as the geometrical micro/nanostructure method. There are many methods to produce superhydrophobic properties on the membrane surface such as radiation-induced copolymerization, self-assembly of stearic acid monolayer on the membrane surface, deposition of a porous crystalline poly propylene coating, grafting fluoroalkylsilane (FAS) on the membrane surface and electrospinning [1,2].In this study, for the first time, Based on the ‘‘lotus effect’’ principle, a novel superhydrophobic porous poly acrylonitrile (PAN)/poly dimethylsiloxane (PDMS) nanofibrous membranes were fabricated by using an electrospinning process. Subsequently, the membranes were grafted with using a low surface energy material (〖CH〗_3 )_2 〖SiCl〗_2/〖CH〗_3 〖SiCi〗_3to form nano-clusters, which were decorated on the microreliefs of electrospun PAN/ PDMS nanofibrous membranes. Scanning Electronic Microscopy (SEM) and Atomic Force Microscope (AFM) analysis showed the micro- and nano-scale structures, similar to lotus leaf, were successfully fabricated on the electrospun PAN/PDMS nanofibrous membranes surface. The water contact angle and sliding angle on the fabricated lotus-leaf-like electrospun PAN/ PDMS nanofibrous membranes surface were 155 and 4°, respectively. This membranes with water repellency property are of interest for different applications such as the self-cleaning and greater separation efficiency of fibrous filter to separate water droplets from oil, etc.