Superhydrophobic and superoleophiclic natural rubber latex foam coated by hexadecyltrimethoxysilane modified halloysite nanotube for oil/water separation

Abstract

In this research, we introduce a facile synthesis of the superhydrophobic natural rubber latex foam (NRLF), sponge-NRLF materials with a high oil-sorption capacity. The superhydrophobic sponge-NRLF was prepared by decorating the halloysite nanotubes (HNTS), which are chemically modified by n-hexadecyltrimethoxysilane (HDTMS) on the surface. The effects of HDTMS@HNTs loading and vulcanization systems towards the superhydrophobic and superhydrophilic properties of the NRLF were investigated. It was found that NRLF vulcanized by conventional vulcanization system (CV) and coated with 6 wt% HDTMS@HNTs showed favorable oil/water selectivity with excellent water repellence with a contact angle of 151°. The modified NRLF showed excellent performance toward gasoline 95 with high sorption capacity, achieving up to 10 times of its own weight for a wide range of oils. Oil sorption capacity tended to decline with respect to increasing HDTMS@HNTs content and oil viscosity due to the reduced porosity and surface area of the modified NRLF. Interestingly, the modified NRLF exhibited excellent durability, as the sorption efficiency remained unchanged after 10 cycles. Moreover, their fire retardant was also improved. • Facile preparation of superhydrophobic and superoleophiclic natural rubber latex foam • Natural rubber latex foam coated by hexadecyltrimethoxysilane modified halloysite nanotube • Oil adsorption capacity and oil-water selectivity of modified natural rubber latex foam