Hybrid anion exchange hollow fiber membranes through sol–gel process of different organic silanes within BPPO matrix

A series of hybrid anion exchange hollow fiber membranes have been prepared through modification of brominated poly (2,6-dimethyl-1,4-phenylene oxide) (BPPO), sol–gel process of different organic silanes and quaternization with triethylamino (TEA). Five different silanes are used, including tetraethoxysilane (TEOS), γ-(2,3-epoxy propoxy)propyl-trimethoxylsilane (GPTMS), γ-aminopropyl triethoxysilane (γ-APS), phenyl-triethoxylsilane (EPh) and γ-methacryloxypropyl trimethoxysilane (γ-MPS). Membrane properties are characterized to show that the hybrid membranes generally exhibit improved thermal stability, mechanical stability and dimensional stability as compared with the membranes without organic silane treatment. Besides, the content and category of the silanes also influence membrane characterizations such as ion exchange capacity (IEC), water content (WR) and dimensional stability. TEOS, EPh and γ-MPS are recommended and the hybrid membranes from them demonstrate IEC in the range of 1.69–1.76 mmol/g, WR 63–72% and dimensional change ratio (DCR) 13–18%. For the recommended membranes, their static and dynamic adsorption and desorption behaviors of a model protein (bovine serum albumin, BSA) have been studied. Results show that the hybrid membranes can demonstrate excellent performance during the adsorption–washing–elution procedures in the permeation mode and the elution percentage can reach ∼95%.