Research On Wettability Of Material Surfaces And Its Application In Separation And Analysis

The treatment of crude oil leakage has become an important task of environmental protection to avoid water pollution. Various methods have been used for crude oil cleanup, including physical absorption by sorption materials, using chemical dispersion to its degradation, in situ burning. Among these methods, the removal and collection of oil from water surfaces using sorbent materials has been considered as one of the most efficient strategies for oil cleanup due to its simple operation process and not causing secondary pollution. Sorbent materials such as organoclays, straw, fiber, hair, and zeolite, are widely applied in practical applications.However, these materials have a lot of limitations such as low absorption capacity,poor absorption rate and recyclabilities. Particularly, most of these materials can not only absorb oils, but also absorb water, due to their poor selectivity, which reduces the separation efficiency. Therefore, it is highly desirable to fabricate novel absorbent materials combined with high absorption capacity, high selectivity, and excellent recyclability for the treatment of oil spillage and the oil-water separation.In this paper, three wettability materials which are low-cost and environmentally friendly can be prepared successfully by a simple method. Three wettability material were characterized by a variety of characterization analysis to study their stability and ability to separate oil and water.1. First, polymethacrylic acid and carbon coated on the surface of melamine sponge. Then, the copper ions were modified through an ion exchange reaction.Finally, the dodecyl mercaptan hydrophobically modified to the doping carbon polymethacrylic acid @ copper @ dodecanethiol melamine sponge(C@PMAA@Cu@DCT MA sponge). The prepared modified sponge was characterized with Fourier transform infrared spectra(FT-IR), water contact angle measurement(CA), scanning electron microscopy(SEM) with energy-dispersive X-ray spectroscopy(EDS), respectively, which show that the C@PMAA@Cu@DCT MA sponge is a kind of environmentally friendly material for oil-water separator with large oil-absorbing and recovery.1. A kind of novel polyurethane sponge was prepared by immersing polyurethane sponge(PU sponge) into modified titanium dioxide hydrosol. The modified titanium dioxide hydrosol was prepared via slo-gel reaction and subsequent hydrophobization with polydimethylsiloxane(PDMS). The entire preparation process is simple, without complicated processes, and the PDMS-TiO2-PU sponge shows a superhydrophobic surface with a water contact angle over 150°.The PDMS-TiO2-PU sponge absorb various oils all above 16.7 g/g in the oil-water mixtures. Moreover, the absorbed oil can be collected by squeezing the sponge, and the recovered sponge can be used repeatedly over 60 times without apparent decrease in absorption capacity.3. A kind of novel modified stainless steel mesh was prepared by immersing stainless steel mesh into modified tin dioxide hydrosol, which was prepared via slo-gel reaction. Subsequently, the superhydrophilic surface was fabricated by high-temperature calcination and UV radiation. The prepared superhydrophilic SnO2@stainless steel mesh was characterized and proved that tin dioxide particles has been successfully modified onto the stainless steel mesh surface. The prepared stainless steel mesh exhibits superior selectivity and separation efficiency(>90%) to organic solvents and different kinds of oil via gravity.These three superhydrophobic sponges exhibit excellent stability, high effectivity and rapid separation of oil/water mixture. The study supplies the theoritical support for the preparation of the oil/water separation materials.