Fabrication of super-hydrophobic filter paper via mixed wax phase separation for efficient oil/water separation

Abstract

Despite previous efforts, the fabrication of superhydrophobic substrate via an environment friendly and easy approach remains a great challenge. In this study, a low cost, simple, and green procedure was developed to prepare a superhydrophobic paper surface that is acceptable for the papermaking industry. First, a wax mixture (beeswax & carnauba wax) was emulsified and coated on the filter paper surface. Then, the coated paper was annealed at different temperatures. The further heat-treatment-rendered wax-coated paper hydrophobic or superhydrophobic because submicrometer or micrometer wax structures were present on the paper surface. The water contact angle of the annealed filter paper sample reached 151.5° at 60 °C, and the sliding angle was under 10°. Further, the relationship between surface composition and the hydrophobic properties of the coated paper samples was discussed. The obtained paper samples showed great potential in water/oil separation, as they had an efficiency over 99%. This work proposed a new simple and mild approach to fabricate superhydrophobic filter papers and explored the hydrophobicity and water/oil separation properties.

Green Superhydrophobic Paper with Self-cleaning Properties Prepared via One-step Impregnation

“…Commonly used materials for the construction of micro/nano rough structure include nano titanium dioxide (TiO 2 ) [32][33] , SiO 2 [34][35] , Al 2 O 3 [36][37] , mixed wax [38] , and zirconia [39][40] . Considering the cost, preparation process, and other factors, inexpensive and easily available TiO 2 nanoparticles were chosen to construct the rough structures of superhydrophobic materials.…”