title: Fluorine-Free Superhydrophobic Coatings with pH-induced Wettability Transition for Controllable Oil-Water Separation.
abstract: We present a simple, environmentally friendly approach to fabricating superhydrophobic coatings with pH-induced wettability transition. The coatings are prepared from a mixture of silica nanoparticles and decanoic acid-modified TiO2. When the coating is applied on cotton fabric, the fabric turns superhydrophobic in air but superoleophilic in neutral aqueous environment. It is permeable to oil fluids but impermeable to water. However, when the coated fabric is placed in basic aqueous solution or ammonia vapor, it turns hydrophilic but underwater superoleophobic, thus allowing water to penetrate through but blocking oil. Therefore, such a unique, selective water/oil permeation feature makes the treated fabric have capability to separate either oil or water from a water-oil mixture. It may be useful for development of smart oil-water separators, microfluidic valves, and lab-on-a-chip devices.
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Wang
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.|College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou 215123, China.
authors.forename: Chuanxiang
authors.initials: C
authors.lastname: Qin
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Xungai
authors.initials: X
authors.lastname: Wang
authors.affiliation: Institute for Frontier Materials, Deakin University , Geelong, Victoria 3216, Australia.
authors.forename: Tong
authors.initials: T
authors.lastname: Lin
keywords: cotton; oil−water separation; pH-responsive wettability; superhydrophobic; superoleophobic