Facile way in fabricating a cotton fabric membrane for switchable oil/water separation and water purification

• Published in: Applied surface science 2018-05, Vol.441, p.500-507
• Main Authors: Li, Yubin, Feng, Ziliang, He, Yi, Fan, Yi, Ma, Jing, Yin, Xiangying
• Format: Article
• Language: English
• Subjects: Adsorption; Cotton fabric; Emulsion; Membrane; Water-oil separation
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.02.060

[Display omitted] •A novel modified cotton fabric (PDA-NiFe2O4@CF) was prepared by one-pot method.•The PDA-NiFe2O4@CF presents superamphiphilicity in air and dual lyophobic behavior under water or oil.•Both two types of emulsions can be separated with the PDA-NiFe2O4@CF.•The PDA-NiFe2O4@CF had good adsorption performance for methylene blue. With dopamine and NiFe2O4 particles, a novel modified cotton fabric (PDA-NiFe2O4@CF) was prepared by one-pot method. Surface morphology, composition of the PDA-NiFe2O4@CF were investigated with SEM, EDX, XRD and FT-IR, respectively. According to the results, the cotton fiber surface was well coated with NiFe2O4 particles. Subsequently, wetting behavior of the modified cotton fabric was determined. The PDA-NiFe2O4@CF is superamphiphilic in air, and a dual lyophobic behavior was indicated with an oil contact angle (OCA) of 153° under water and a water contact angle (WCA) of 145° under oil. The rough micro-nano scale surface structure and high-surface-energy compositions of the PDA-NiFe2O4@CF makes the surface to be easily covered by one medium and enables it to repel other unmixable medium simultaneously. Therefore, water–oil mixtures can be separated on demand. Besides, with the unusual dual lyophobic surface of PDA-NiFe2O4@CF, both two types of emulsions were separated by gravity driven. On the other hand, it was also found that the as-prepared PDA-NiFe2O4@CF had good adsorption performance for methylene blue.