High water flux poly(acrylonitrile-co-methyl acrylate) membranes fabricated via thermally induced phase separation

ABSTRACT In this study, a melt processable poly(acrylonitrile-co-methyl acrylate)(P(AN-MA)) copolymer was used as membrane matrix, caprolactam (CPL) and glyceryl triacetate (GTA) were used as an eco-friendly mixed diluent. P(AN-MA) membranes with inter-connected sponge structure and porous surface were successfully fabricated via thermally induced phase separation (TIPS). The optimum ratio of CPL/GTA in the mixed diluent was 1:1 wt.%. Even though the concentration of P(AN-MA) was up to 25 wt.%, the surface of membrane still exhibited microporous structure. When the concentration of P(AN-MA) was 15 wt.%, the membrane formed in 20 °C air bath showed the highest water flux of 6802 L/m 2 h. With the increasing of copolymer content or cooling rate, the pore size decreased. In addition, all of the P(AN-MA) membranes exhibited a rejection to carbon ink more than 90 wt.%. The average pore size of the membranes was less than 270.5 nm, and the tensile strength was more than 2.8 MPa. It is anticipated that the facile and green technology TIPS will bring the P(AN-MA) membrane a step closer for practical applications, including clean-up of oil spills, waste water treatment, fuel purification, and separation of commercially relevant emulsions.