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 degrees to 128 degrees. 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.