Polyamide Thin Films Grown on PD/SWCNT-Interlayered-PTFE Microfiltration Membranes for High-Permeance Organic Solvent Nanofiltration
Yang Lü, Zhenyi Wang, Wangxi Fang, Yu Zhu, Yatao Zhang, Jian Jin
Abstract
Porous polymeric support membranes with outstanding organic solvent resistance are highly required for fabricating thin-film composite (TFC) organic solvent nanofiltration (OSN) membranes. In this work, we report the fabrication of a high-permeance TFC-OSN membrane by the use of a polytetrafluoroethylene (PTFE) microfiltration membrane loaded with single-walled carbon nanotubes coated by a polydopamine (PD/SWCNT) network film (named the PD/SWCNT/PTFE composite membrane) as the support. Through interfacial polymerization between m-phenylenediamine and trimesoyl chloride, a polyamide (PA) thin film has successfully grown on the surface of the PD/SWCNT/PTFE composite membrane. The resulting PA TFC-OSN membrane exhibits a high methanol permeance up to 13.2 L m–2 h–1 bar–1 with a rejection rate of 89.6% to 6-hydroxy-2-naphthalenesulfonic acid sodium salt (HNSA, Mw = 246.21). Moreover, the rejection rates of the PA TFC-OSN membrane to various dyes remain unchanged before and after DMF activation, indicating that it possesses an excellent resistance to organic solvents.