The Preparation Of Some Filter Membranes With Special Wettability And Properties For Oil/Water Separation

With the continuous development of traditional industries, waterbody remediation has became a worldwide problem especially for oil spills and oily industrial wastewater. Traditional oil/water separation patterns include centrifugation, gravitational method, adsorption method, flotation method, bio oxidation process, chemical method, etc. However, the separation efficiency or effect by above-mentioned methods is not good because of unconspicuous interface wettability. Oil/water separation is interface science problem in essence. So how to utilize special wettability of materials resulting in oil/water separation is an important research aspect. Therefore, this paper describes some surfaces with palygorskite, silicon dioxide or zinc oxide by simple and feasible method. And researchs the application in oil/water separation for waterbody remediation. The main research contents and conclusions are as follows:1. Hydrophobic attapulgite nanoparticles are obtained through a simple liquidphase reaction between octadecyltrichlorosilane and hydrophilic attapulgite nanoparticles. Then the mixtures of hydrophobic attapulgite nanoparticles and waterborne polyurethane are added in the absolute acetone, the resulting suspensions are sprayed onto stainless steel mesh to form superhydrophobic attapulgite surfaces. The superhydrophobic surface can separate the mixtures of water and kerosene, chloroform, petroleum ether, tetrachloroethane, toluene and the separation cycle number could be above 40 times to kerosene/water mixture.Similar to St(?)ber method, robust and stable fabrics with both sides showing superhydrophobic and superoleophilic properties is fabricated by a simple, effective and one-step sonochemical irradiation approach. The as-prepared superhydrophobic fabrics can separate and capture oils from water with high separation efficiency, good recyclability and fast capture kinetics, and consequently show promise for the separation of oil–water mixtures. In addition, the as-prepared fabrics exhibite stable, high hydrophobicity towards many corrosive solutions(acidic, basic, salt liquids), hot water, and mechanical abrasion. When filled with polyurethane sponges, forming superhydrophobic bag, it can capture bulk oils from water with high-speed. Subsequently connected with a vacuum system, the superhydrophobic bag filled with PU sponges can continuously and ultrafast remove oil from water surfaces with high efficiency.2. The superhydrophilic attapulgite surface is prepared by spraying suspensions, which consist of hydrophilic attapulgite nanoparticles and waterborne polyurethane, onto copper mesh. According to the underwater superoleophobic property, the mesh could separate kerosene/water mixture with separation efficiency up to 99.6% and the mush maintains stable recyclability after 50 separation cycles with the surface morphology of the palygorskite coated mesh nearly unchanged. Furthermore, the attapulgite coated mesh exhibits excellent environmental stability under a series of harsh conditions, which are used for the separation of mixtures of oil and various corrosive and active aqueous solutions, including strong acidic, alkaline, or salt aqueous solutions, even hot water.3. A photo-induced ZnO coated mesh for on-demand oil/water separation was fabricated by a facile spray-coating method. The reversible wettability change of mesh between the superhydrophobicity and the superhydrophilicity/underwater superoleophobicity could be achieved through alternate UV irradiation and heat treatment. So the surface of oil/water separation mode was tuned between the oilremoving to the water-removing in one single device.