title: O-(carboxymethyl)-chitosan nanofiltration membrane surface functionalized with graphene oxide nanosheets for enhanced desalting properties.
abstract: A novel O-(carboxymethyl)-chitosan (OCMC) nanofiltration (NF) membrane is developed via surface functionalization with graphene oxide (GO) nanosheets to enhance desalting properties. Using ring-opening polymerization between epoxy groups of GO nanosheets and amino groups of OCMC active layer, GO nanosheets are irreversibly bound to the membrane. The OCMC NF membranes surface-functionalized with GO nanosheets are characterized by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, contact angle analyzer, and zeta potential analyzer. The membranes exhibit not only higher permeability but also better salt rejections than the pristine membranes and the commercial NF membranes; besides, the desalting properties are enhanced with the concentration of GO nanosheets increasing. Furthermore, the transport mechanism of GO-OCMC NF membranes reveals that the nanoporous structure of GO-OCMC functional layer and size exclusion and electrostatic repulsion of water nanochannels formed by GO nanosheets lead to the membranes possessing enhanced desalting properties.
authors: Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education and ‡College of Chemistry and Chemical Engineering, Ocean University of China , Qingdao 266100, China.
authors: Jiali
authors: J
authors: Wang
authors: Xueli
authors: X
authors: Gao
authors: Jian
authors: J
authors: Wang
authors: Yi
authors: Y
authors: Wei
authors: Zhaokui
authors: Z
authors: Li
authors: Congjie
authors: C
authors: Gao
keywords: O-(carboxymethyl)-chitosan; desalination; graphene oxide; nanofiltration membrane; surface functionalization