SI‐ATRP Polymer‐Functionalized Graphene Oxide for Water Vapor Separation

Graphene oxide is functionalized with poly(2-diethylaminoethyl) methacrylate (PDEAEMA), and the resulting material is used as a selective layer of a thin-film composite membrane (TFCM). The polymer synthesis is carried out by surface-initiated atom transfer radical polymerization (SI-ATRP) from bulk and also from single-layer graphene oxide (GO). The polymer brushes synthesized by the "grafting from" method are characterized by size exclusion chromatography (SEC), nuclear magnetic resonance spectroscopy (NMR), Fourier-transform infrared (FTIR) spectroscopy, thermal gravimetric analysis (TGA), and TGA-FTIR. The TFCMs are prepared by the deposition of the selective layer from a stable polymer solution. The molecular weight of the polymer is sufficiently high to obtain a continuous defect-free layer on a porous support. The thickness of the selective layer is approximate to 400 nm, as found in morphological investigations by scanning electron microscopy (SEM). The obtained membranes are utilized for gas and water vapor transport experiments in a wide temperature range. The water vapor permeability coefficient of the investigated materials is up to 4500 Barrer; this value increases threefold upon quaterization of the amine. The high permeance and selectivity for water vapor make this type of thin-film membranes a potential candidate for membrane distillation.