Fabrication of robust superhydrophobic filter paper for oil/water separation based on the combined octadecanoyl chain bonding and polymer grafting via surface-initiated ATRP

Abstract Effective separation of oil and water has always been a long-term challenge. Here we introduce a facile and fluorine-free method to fabricate superhydrophobic and superoleophilic filter paper without the decoration of solid particles for robust oil/water separation. After chemically bonding octadecanoyl and α-bromoisobutyryl groups on the surface of filter paper through simultaneous esterification with stearoyl chloride and α-bromoisobutyryl bromide (BiBB) to obtain C18-FP-g-Br, superhydrophobic poly(styrene-co-acrylonitrile) (SAN) grafted filter paper (C18-FP-g-SAN) was fabricated via surface-initiated atom transfer radical polymerization. The obtained C18-FP-g-SAN showed a water contact angle of 153° and achieved a separation efficiency exceeding 98.5% after ten different typical oil/water separation processes due to the synergistically combined contributions of bonded octadecanoyl chain and grafted SAN. C18-FP-g-SAN remained high separation efficiency after 10 cycles of use and treatment with strong acidic or basic solution. The excellent reusability and chemical stability of C18-FP-g-SAN promise its practical applications of continuous oil/water separation and oil spillage cleanup. Graphic abstract