Preparation Of Cotton Fabric And Foam With Special Wettability And Their Application In Oil-water Separation

The oil leakage causes wasted oily sea water,which has a catastrophic influence on the environment,throws a serious threat to the health of human beings as well as survival of other bio-organismst.Hence,the problem should be solved as soon as possible.Currently,materials with special wettability have been used in oil-water separation due to their special wettability to water and oil.However,the current preparation methods of materials with special wettability need tedious steps and harsh reaction conditions,and the prepared materials have disadvantages such as poor durability,high price,and poor oil-water separation performance,which greatly limit the practical application.Therefore,a fluorine-free durable superhydrophobic cotton fabric was fabricated by a simple and mild click chemistry method.Its durability in various harsh environments was explored,and its key oil-water separation performance was analyzed.A p H-responsive melamine foam was firstly prepared by efficient and facile chain transfer radical polymerization,and its wettability,response mechanism,oil absorption and oil recovery properties were studied.Its main contents and conclusions are as follows:(1)A facile and simple preparation route is designed to fabricate durable non-fluorine superhydrophobic cotton fabric,with grafting SiO₂and PDMS to the surface of cotton fabric via thiol-ene click reaction.CF-S-PDMS/SiO₂ shows excellent hydrophobicity with achieving a water contact angle of 159°and a slide angle of 7°.Besides,due to the strong chemical bond between the cotton fabric and the modifier,CF-S-PDMS/SiO₂ can maintain superhydrophobic even exposed in harsh environment such as high temperature,abrasion,alkali,acid and UV light.Moreover,CF-S-PDMS/SiO₂ exhibits excellent oil/water separation ability with a high permeation flux of over 20 KL·m^-2·h^-1and high separation efficiency(CCl₄-water)of over 97%after fifty cycles.(2)A fast p H-responsive and highly effective melamine foam(MF)grafted with poly(2-dimethylaminoethyl methacrylate)is prepared by surface-initiated chain transfer radical polymerization.The as-prepared MF displays superhydrophilic and superoleophobic surface in strong acid solution while it becomes superhydrophobic in neutral or basic solution.Therefore,it can be rapid to selectively absorb different types of oils from the oil–water mixture with a great absorption capacity of 54-117 g g^-1 and automatically desorb oil in less than 60 s with a desorption efficiency of 99%(dichloromethane)in acid solution.Moreover,the as-prepared MF possesses excellent recyclability:the desorption efficiency is over 90%even after 15 cycles.