Batch adsorption performance of methyl methacrylate/styrene copolymer membranes

Methyl methacrylate (MMA)/styrene copolymer membranes with different feed molar ratios of monomers are reported. The copolymer structure and properties were examined by contact angle measurements, FT-IR and 1H-NMR spectroscopy. Membranes were fabricated by casting a liquid film of 15-20 wt% copolymer in 1-methyl-2-pyrrolidinone that was exposed to air of 90% relative humidity for 3 min and then immersed into a 25 °C deionized water bath. A sponge-like morphology was observed for the copolymer membranes. The specific surface area and water content increased with increasing MMA/styrene ratio. In addition, the batch adsorption performance for various molecules (quercetin, proteins, α-tocopherol, and flavonoid glycosides in Ginkgo biloba L. extract) was investigated. The higher was the MMA/styrene molar ratio, the greater the related adsorption capacity was. In three cycles of batch adsorption/desorption operation, the content of flavonoid glycosides could be raised from 3.1 wt% to 14 wt%.