Synthesis of hydrophilic polysulfone membranes having antifouling and boron adsorption properties via blending with an amphiphilic graft glycopolymer

Boron removal remains a challenge to environmental engineering and material science. Novel hydrophilic polysulfone (PSF) membranes were prepared via nonsolvent induced phase inversion of the blend of a PSF-based amphiphlic graft glycopolymer and PSF. The graft glycopolymer was synthesized via the atom transfer radical polymerization (ATRP) of glycidyl methacrylate (GMA) grafted from chloromethylated polysulfone (CMPSF), followed by epoxy ring-opening reaction with N-methyl-d-glucamine (NMG). The resulted PSF-g-PNMG membranes were characterized by means of ATR-FTIR, XPS, FESEM and WCA measurements. The ATR-FTIR and XPS results indicated successful anchoring of NMG groups and aggregation of PNMG hydrophilic segments at the membrane surface. The PSF-g-PNMG membranes were demonstrated to have more hydrophilic surfaces, more open porous structures, higher permeation flux and better anti-fouling properties than the PSF control membrane. The effects of initial boron concentration, adsorption time, solution pH, ion strength and temperature on boron adsorption properties are systematically studied. The boron uptake of 0.193 mmol/g can be obtained within half an hour of contact time in 300 mg/L boron solution. The optimized conditions are pH of 6-8 at room temperature. The adsorption isotherms can be described by the Langmuir model and the adsorption kinetics fitted well to the pseudo-second-order rate expression.