Synthesis of Hybrid/Superhydrophobic Coupling Agent Grafted Nano SiO2 and Its Use in Fabrication of Rubber Nanocomposite with Outstanding Oil/ Water Separation Capability

Design and synthesis of a new sorbent with high performances of oil -water separation is one of the challenges to the world community. Herein, a superhydrophobic/novel coupling agent (NCA) containing several vinyl groups was synthesized. Also, vinyl isocyanate (VI) and tetraethoxysilane (TEOS) reacted with a synergetic strategy of crosslinked networks through the click reaction under N 2 gas atmosphere. 1 H NMR and FTIR analyses confirmed the formation of NCA with the SiC 10 H 18 O 6 N 2 chemical formula. Then, NCA was grafted on the nanoparticles at different amounts by sol-gel method. It was found that the surface modification of nanoparticles enhanced the water contact angle (WCA) from 60 degrees to 163 degrees . In the following, nanoparticles with and without NCA were applied at different contents to tire rubber compound. The uniform dispersion/distribution of the grafted nano fillers with NCA in polymer matrix and the strong filler-polymer interactions enhanced crosslink density and improved the mechanical performances of the rubber sample. The prepared nanocomposites were tested against absorption of different oils. The results showed that the superior nanocomposite with modified nanoparticles (i.e. TR-TNS5) had a separation efficiency of over 90 % compared to the nanocomposite with pure nanoparticles (i.e. TR-NS5) which had a separation efficiency of less than 30 %. Also, the separation cycle of nanocomposites improved by 95 % after addition of the modified nanoparticles (from 240 to 440 cycles). The modified nanocomposite illustrated contact angles of 153.22 degrees and 13.34 degrees with water and oil droplets, respectively. The results showed that the modified rubbery nanocomposite confirmed superior mechanical and oil -water separation performances.