Preparation Of Superwetting Interface Materials And Its Application In Oil-Water Separation

The frequent oil spillage accidents are always accompanied with catastrophic influence in the world,resulting in irrecoverable damage to the marine environment and ecosystem.Therefore,the treatment of oil spills has gained an increasing attention in the world.As for the treatment of oily wastewater,the traditional methods could not meet the requirements for lower energy consuming and more efficient technologies.In recent years,inspired by the superwetting phenomenon in nature,the oil-water separation interface materials,such as superhydrophobic/superoleophilic,superhydrophilic/underwater superoleophobic material,have been made and are seen to be very promising for the application on oil/water separation.However,these materials exist the following shortcomings,such as complex preparation process,poor stability,expensive raw materials and secondary pollutions to environment.In order to solve these problem,we have developed three kinds of superwetting interface materials,which could be used for various oil-water separation.The main research contents are as follows:1.Oil leakages often cause fatal disasters for environmental pollution,but an efficient treatment of the oil spills is still very challenging.Sponge-substrates with superhydophobicity and superoleophilicity have been attracted much attention for oil/water separation.In this study,an inexpensive commercial melamine sponge was chemically modified for the uses of oil spills treatment by oil/water separation.Inspiring from the superhydrophobic property of lotus leaf,pyrrole was polymerized by a simple vapor-phase deposition to encapsulate the raw melamine-formaldehyde(MF)sponge.The as-formed thin polypyrrole walls were utilized as reducing reagent to generate Ag nanoparticles on the capsuled sponge.Accordingly,a superhydrophobic melamine sponge with a two-tier hierarchical structure was achieved after fluorination,and this material was applied to absorb oil from water.The absorption capacity,absorption rate and recyclability were investigated.This superhydrophobic sponge exhibited an efficient and fast oil/water separation performance in complicated environment and could be applied in industrial production because of its low cost and simple fabrication procedure.This study presents a facile strategy for the fabrication of efficient oil sorbents based on a two-tier hierarchical structure,providing a novel means for the upgrading of engineered sorption materials.2.We prepared a robust superhydrophobic/superoleophilic cotton fabric.First,pyrrole was polymerized by a simple vapor-phase deposition to encapsulate the raw cotton fabric.And then,the cotton fabric was modified by stearic acid.The water contact angle of the superhydrophobic cotton fabric was 155.79~o±1.5~o,sliding angle was less than 10~o.The oil rapidly permeates into the as-prepared sample while water is completely rejected,so pure oil could rapidly separate from oil-water mixture.3.With the rapid development of industrialization,the deterioration of water resources,especially oily wastewater pollution,is becoming a worldwide threat,because it is severely harmful to biological and human safety.Recently,porous meshes with superhydrophilicity and underwater superoleophobicity have attracted significant attention due to their low oil adhesion and selective oil-water separation.However,simple,environmentally friendly,low-cost,multifunctional and facile scaled-up materials are still urgently in demand.Here,a natural polymer-based hydrogel prepared by konjac glucomannan(KGM)was coated on glass fabric,a kind of engineering material.The resulting hydrogel-coated glass fabric not only shows excellent performance of water removal from oil-water mixture but also can remove organic dyes and heavy metals in water simultaneously during the oil-water separation process.In addition,due to the strong hydration capacity,the DKGM hydrogel coated glass fabric shows underwater ultra-low-oil-adhesive superoleophobicity to viscous oils,which means it is self-cleaning with respect to oils in an aqueous environment and can be easily recycled for long-term use.Importantly,the superhydrophilicity and underwater superoleophobicity of these hydrogel-coated glass fabrics were maintained under various harsh conditions.The low-cost,biodegradable and environmentally friendly preparation,resistance to harsh conditions and multifunctional applications properties make these hydrogel coated glass fabrics hold great potential for purifying oily wastewater.