Silane Functionalized Polyvinyl-Alcohol Formaldehyde Sponges on Fast Oil Absorption

A series of silane functionalized polyvinyl-alcohol formaldehyde sponges (PVF-DTMS-x) containing hydrophobic Si–O–Si and dodecyl(−(CH2)12−) groups was synthesized. The PVF-DTMS-x sponges were obtained through hydroxyl groups (−OH) on the surface of the pristine PVF sponge skeletons reacting with dodecyltrimethoxysilane (DTMS) to be applied as fast oil absorption materials. The as-prepared PVF-DTMS-x sponges had an average pore size of 91.0 μm, which was similar to that of the pristine PVF sponge. Compared to the pristine PVF sponge, which had a superhydrophilicity (water contact angle, WCA = 0°), the silane functionalized PVF (PVF-DTMS-x) conferred PVF hydrophobic properties with WCA values higher than 125°. Among them, PVF-DTMS-69.48% had the highest WCA value of 147.6°. The oil absorption capacities of PVF-DTMS-x sponges were tuned from 4.0 to 14.0 g·g–1 in different solvents (benzene, chlorobenzene, carbon tetrachloride, dichloromethane, diesel oil, coal oil, colleseed oil), and all samples were saturated within a fast time of 15 s. Especially, PVF-DTMS-45.32% as a typical sponge displayed prominent oil absorption selectivity on CH2Cl2 in a CH2Cl2/H2O mixture. Furthermore, PVF-DTMS-x sponges had a stable oil absorption capacity and volume swelling after 10 cycles. The PVF-DTMS-x sponges also owned better mechanical properties than the pristine PVF sponge at dry and oil absorbed states. These comprehensive results show that PVF-DTMS-x sponges exhibit the potential to serve as a fast oil absorption material.