Development of a molecular separation membrane for efficient separation of low-molecular-weight organics and salts

A positively charged nanomaterial was prepared adopting the graft polymerization of ionic liquid monomers on halloysite nanotubes (HNTs) via reverse atom transfer radical polymerization (RATRP). A novel and facile organic-inorganic hybrid molecular separation membrane was then fabricated by the incorporation of modified HNTs via phase inversion method. This hybrid membrane was investigated in terms of morphology structure, hydrophilicity, thermal, mechanical and electrical properties, and separation performances. The results revealed that the hybrid membranes represented thickened and loosened skin layer, enhanced surface hydrophilicity and water flux, as well as good thermal and mechanical properties. Most importantly, the hybrid membranes showed stabilized rejection for Reactive Black 5 (above 90%) and Reactive Red 49 (80%-90%), whereas the rejection for sorts of salts declined to below 10% indicating a potential molecular separation characteristic for dye desalination.