Fouling resistance of novel amphiphilic polyampholyte membranes with varying hydrophobicity towards common foulants and cell culture media

Abstract

Self-assembly is a spontaneous and scalable manufacturing method to create much-needed fouling resistant membranes with narrow pore size distributions. However, there is a limited number of self-assembled membrane chemistries that can access pore sizes below 2 nm. Novel thin film composite membranes with a selective layer manufactured from a random Polyampholyte Amphiphilic Copolymer (r-PAC) have an effective pore size of 1.5 nm, relevant to various nanofiltration and water treatment applications. This is the first study that reports the membrane performance of novel r-PAC layers, prepared with varying degrees of ionic content, in filtering several classes of foulants (oil, organics, proteins, and complex mixtures). The net neutral charge of the r-PACs used enabled steady salt rejections independent of the ionic strength of the feed. The best performing r-PAC membrane composition showed no irreversible flux decline in all fouling tests and was further tested with a realistic feed, a complex cell culture media mixture utilized in cellular agriculture. This membrane exhibited an impressive 0 % irreversible flux decline after filtering the cell culture media for 20 h while a comparable commercial membrane exhibited 90 % irreversible flux decline. The chemical stability and excellent fouling resistance behavior of these membrane materials to a broad range of feeds implies these materials can enable the filtration of feeds with extreme fouling potential in biomanufacturing, wastewater treatment, and resource recovery applications.