Thin-Film Composite (TFC) Polydimethylsiloxane (PDMS) Membrane with High Crosslinking Density Fabricated by Coaxial Electrospray for a High Flux
Haijie Qing, Senqing Fan, Yangchao Liu, Chuang Li, Jiaxin Meng, Mingxia Yang, Zeyi Xiao
Abstract
To obtain thin-film composite (TFC) polydimethylsiloxane (PDMS) membranes for a high flux, the coaxial electrospray strategy was applied and an electrospray apparatus was self-assembled for membrane fabrication. The behavior of micron-sized dispersed droplets forming a contiguous membrane was explored. During the electrospray process, the structure of the PDMS membrane can be regulated and the thickness of the membrane can be precisely controlled. The TFC PDMS membrane without defects can be as thin as 2.3 μm. The crosslinking density of the electrosprayed TFC PDMS membrane was over 2.0 × 10 –3 mol cm –3, which was 34% higher than the conventional casted membrane. During the pervaporation process with the TFC PDMS membrane for ethanol recovery, the membrane achieved a flux of 2522 g m –2 h –1 at 40 °C, which was over two times higher than that of the casted one, without compromising the expected separation factor. Besides, the TFC PDMS membrane performed good stability for a long time.