A highly reusable polydimethylsiloxane sorbents for oil/organic solvent clean-up from water

Abstract

Frequent oil spills in recent years due to human activities including oil drilling, tanker accidents or industrialization, give rise to an urgent need for the development of sorbent materials with high sorption ability, good selectivity and reusability. In this work, PDMS based hydrophobic sorbents acting as oil removing agents were fabricated via bulk polymerization of tetraethyl orthosilicate (TEOS) and different lengths of polydimethylsiloxane (PDMS), without using any activator, initiator, catalyst or solvent. The PDMS sorbents were characterized by using FTIR, C-13 and Si-29 CPMAS NMR, SEM, contact angle measurements, and thermal gravimetric analysis. The results show the successful preparation of the crosslinked sorbent structure with water contact angle (WCA) of 123 degrees, indicating its hydrophobic structure. The prepared sorbents have high swelling ability in organic liquids/oils in the range of 9-21 g g(-1). They have the ability to quickly absorb the oil from the water surface and float before and after oil sorption, while the capacity of the sorbents did not change in different water types. They can be reusable for at least 10 absorption-desorption cycles without capacity change, and have stability in oils over 300 cycles, demonstrating that the obtained hydrophobic PDMS sorbents can be used as oil removing agents in the field of oil spill applications.