Polyacrylamide and poly(N,N-dimethylacrylamide) grafted cellulose nanocrystals as efficient flocculants for kaolin suspension

Natural polymer flocculants for wastewater treatment have received close attention in recent years. Here we used two flocculants, polyacrylamide and poly(N,N-dimethylacrylamide) grafted cellulose nanocrystals synthesized by a "macro-RAFT assisted" strategy, for the flocculation of kaolin suspension. The flocculation performance of these two flocculants, including flocculants dosage, settling time and floc size, was carefully studied and compared. Results suggested that poly(N,N-dimethylacrylamide) grafted cellulose nanocrstyals showed better flocculation performance than polyacrylamide grafted ones. Meanwhile, their flocculation behavior was also compared with other cellulose-based flocculants in literature and we suggested polymer modified cellulose nanocrstals as flocculants might have higher flocculation performance, but this needs further verification.