Functionalization of cellulose via ATRP and “click” chemistry to construct hydrophobic filter paper for oil/water separation

Cellulosic materials show great superiority in oil/water separation owing to abundance, low cost, renewability and biodegradability. Herein, silylated cellulose graft copolymer (C-PGMA-S) was prepared by combing ATRP grafting of glycidyl methacrylate with ring-opening reaction between epoxy groups in grafted chains and amine groups in (3-Aminopropyl)- triethoxysilane. C-PGMA-S was utilized to construct hydrophobic surface for filter paper substrate conveniently through dipping and drying. As the curing proceeded, water contact angle of the modified paper increased from 77° to 128°. Inhomogeneous coverage on the pores and micro-scaled irregular concavities were observed by scanning electron microscopy (SEM) on modified paper, resulting in decreased porosity and increased roughness. Moreover, bursting strength was improved by 27%. An efficiency of 96.8% was achieved using the modified paper for oil/water separation. The modified paper exhibited moderate reusability with the separation efficiency remaining over 90% after reuse for 8 cycles without renewing process and good stability against pH variations. The C-PGMA-S modified filter paper, which is fluorine-free, might be a potential candidate for oil/water separation.