Plasma polymerization of octafluorocyclobutane and hydrophobic microporous composite membranes for membrane distillation

Abstract

SYNOPSISIn this paper, hydrophilic microporous cellulose nitrate membranes have been surfacemodified by plasma polymerization of octafluorocyclobutane (OFCB) . The microporous composite membranes with a hydrophilic layer sandwiched between two hydrophobic layers have been obtained. The obtained composite membranes have been used in a membrane distillation ( MD) process and have exhibited good performance. The effects of polymerization conditions, such as glow-discharge power and deposition time, on the structures and MD performances of the obtained composite membranes have been investigated by SEM, X-ray microscopical analysis, and XPS. The polymerization conditions should be as mild as possible in order to prepare the hydrophobic composite membrane with good MD performance. The typical MD behaviors of the obtained hydrophobic composite membranes are in agreement with that of hydrophobic membranes directly prepared from hydrophobic polymeric materials, like PVDF, PTFE, or PP.

Advances in Membrane Distillation for Water Desalination and Purification Applications

“…Membranes made of a single polymer or copolymers have been processed since the early 1990s at laboratory scale [257]. As described in Section 4.1, commercial micro and ultra-filtration membranes made of PVDF, PTFE and PP have been used for decades as MD membranes.…”

“…However early works also considered using hydrophilic membranes, such as cellulose acetate. These membranes were used either as supports for the deposition of more hydrophobic materials [259] or surface modified to render them hydrophobic [257]. …”

Membrane Distillation: Principle, Advances, Limitations and Future Prospects in Food Industry

“…However selection of a thicker membrane decreases both the flux and permeability. One promising approach may be selection of a membrane with higher porosity since thermal conductivity of polymer membrane is significantly higher than thermal conductivity of water vapour in the membrane pores (Brodard et al, 2003;Bryjak et al, 2000;Chanachai et al, 2010;Huo et al, 2010;Kong et al, 1992;Krajewski et al, 2006;Lai et al, 2011;Li & Sirkar, 2004;VargasGarcia et al, 2011;Wu et al, 1992;Yang et al, 2011b) have been attempted until now. However, there is very limited number of studies on the design of MD membranes (Khayet, 2011;Khayet et al, 2010;Phattaranawik et al, 2009;Wang et al, 2009;Yang et al, 2011a).…”

Preparation of hollow fibre membranes from PVDF/PVP blends and their application in VMD

“…In fact, the hydrophilic part provides mechanical support with low resistance to transport, leading to high fluxes, while the modified surface ensures the required hydrophobicity [22][23][24][25][26][27][28][29][30][31][32][33][34].…”