Polyethylene Coated with MnO۲ Nanoparticles as Thin Film Composite Membranes for Organic Solvent Nanofiltration

A thin film composite (TFC) membrane with superior characteristics for organic solvent nanofiltration (OSN) was successfully prepared. Accordingly, a state-of-the-art polyethylene (PE) membrane support was first prepared through etching the polystyrene (PS)/styrene-ethylene-butylene-styrene (SEBS) phase, as the dispersed phase, from the fabricated PE/SEBS/PS composite by using the solvent extraction technique. Due to the high hydrophobicity of the prepared PE membrane support (Etched PE) and lack of polar functional groups on its surface, the impregnation with an m-phenylenediamine (MPD) aqueous solution, and consequently, the formation of the polyamide layer on the PE surface was restricted. Hence, the prepared PE membrane supports were immersed in potassium permangenate (KMnO۴) solutions so that the PE surface was oxidized, by which polar functional groups were generated, and manganese (IV) dioxide (MnO۲) nanoparticles were also formed on the surface via a relatively strong bond. Next, MPD and trimesoyl chloride (TMC) monomers were utilized for the formation of the cross-linked TFC layer on the MnO۲-loaded PE surface. The TFC membranes showed a hydrophilic and defect-free polyamide barrier layer, high separation performance (dye rejection as high as ۹۹.۸% for Methyl Green), methanol permeance of ۷ L/m۲.h, and high methanol permeance after DMF activation (۱۴ L/m۲.h). Furthermore, a superior solvent resistance (dye rejections of more than ۹۸.۵, ۹۷, ۹۶ and ۹۳.۵% for methyl green, rhodamine B, crystal violet and methylene blue, being immersed in DMF at ۷۵°C for about ۱۰۰ days) was exhibited by the prepared membranes, which demonstrated their promising potential in the OSN applications.

کلیدواژه ها:

TFC membrane ، Binary composite ، MnO۲ Nanoparticles ، Etching ، Organic solvent nanofiltration (OSN)