Preparation of Superhydrophobic Coatings on Filter Paper for Oil-Water Separation

Abstract

Oil-water separation has become the prime concern for fossil fuel exploration industries. In the present study, superhydrophobic coating on filter paper was prepared to repellent water while allowing oil to flow freely from its porous structures. Coating was generated by solution-casting technique on cellulosic filter paper using silica nanoparticles (SiO2) along with silane coupler hexadecyltrimethoxysilane (HDTMS). The contact angle was measured, and it has shown 175.1° ± 1.5°, and the tilting angle is 1.5° ± 0.2°. The surface topography of coated and treated samples was also examined. Furthermore, thermal stability of fabricated filter papers was evaluated by annealing at a different range of temperatures (20 °C-220 °C). The pH resistance of the coatings were inspected by immersing the specimens in acidic and alkali solutions (pH 2-13). The mechanical durability was examined by tape-peeling and abrasion tests. Moreover, these samples have shown waterjet impact resistance. Filtration study was performed on coated filter papers using various oil-water mixtures of kerosene-water and petroleum ether-water and results have shown the separation efficiency of 99% and 98.5%, respectively. Thus these filter papers can have potential practical and industrial applications.