Surface modification of commercial aromatic polyamide reverse osmosis membranes by graft polymerization of 3-allyl-5,5-dimethylhydantoin

Improving the water flux and bio-fouling resistance of reverse osmosis (RO) membrane through surface modification by zwitterionic polymer

“…As confirmed by previous studies [30,31], the most probable grafting sites in aromatic polyamide chains are at amine and carboxylic acid end groups, and also may at the amide II groups (N-H) in polyamide chains. The DMAEMA-polymer chains were connected to the membrane backbone through covalent bond.…”

Influence of chitosan coating on the separation performance, morphology and anti-fouling properties of the polyamide nanofiltration membranes

“…So, pretreatment of polluted feed solution and surface modification of membrane surface to lower charge and roughness and enhancement of hydrophilicity properties is a potential procedure to improving anti-fouling membranes. Several strategies exist to hydrophilic modification of membrane surface including: new interfacial polymerization monomers [7], improvement of interfacial polymerization process [8], surface adsorption [9,10], surface coating [11,12], hydrophilization treatment [13], radical grafting [14,15], chemical coupling [16,17], plasma polymerization or plasma-induced polymerization [18], initiated chemical vapor deposition [19] and incorporation of nanoparticles into the membrane structure [20,21]. But, most of these methods need to special instruments or conditions which limit their application.…”

Functional Aromatic Polyamides

“…The surface hydrophilicity was also improved, showing high anti-fouling properties to the positively charged pollutants. Wei et al [79] and Zhang et al [80] modified commercial membranes adding 3-allyl-5,5-dimethylhydantoin by a free-radical graft polymerization process, finding, for example, that the chlorinated grafted membranes had remarkable sterilization The correlation between gas and vapor separation characteristics of aromatic polyamides with the bulkiness of the aramids was studied theoretically. Chang et al [76], adopted several simulation techniques, such as molecular dynamics or the Monte Carlo method, to analyze free volume, fractional accessible volume and the size and shape distributions of the free volume, showing that bulky groups in the membranes promote the formation of a continuous and larger free volume.…”