| With the acceleration of industrialization,the pollution of crude oil and chemical reagents in the process of industrialization has seriously threatened the sustainable development of mankind in recent years.Therefore,the effective treatment of oil and organic pollutants has become one of the most urgent problems.The traditional methods,such as combustion,gravity sedimentation,centrifugation or chemical dispersion,can be used to in some extent.As for these separation methods,however,the disadvantages of high energy consumption,low separation efficiency and secondary pollution make the separate of oil/water mixture a huge challenge in practical applications.Therefore,it is of great significance to develop a novel and efficient membrane separation method.In the present,there are some shortcomings among the oil/water membrane separation materials,such as unalterable structure,low porosity,complex fabrication process and tedious post-processing.Since melt-blown microfiber membrane possesses the advantages of small fiber diameter,high specific surface area and high porosity.It is easy to be functionalized and adjust the structure.We developed some facile strategies to regulate the structure and wettability of the melt-blown microfiber membrane,and prepared a series of oil/water separation membrane materials.The research is concluded as below:(1)Inspired by the superhydrophobic phenomenon on the lotus leaf surface,we developed a simple spray method to fabricate superhydrophobic and superoleophilic polyphenylene sulfide(PPS)microfiber membrane by constructing hierarchical structures on the membranes surface.The effect of polytetrafluoroethylene(PTFE)content on the surface morphology and wettability of melt-blown PPS microfiber membranes was carefully evaluated.Meanwhile,the mechanism of oil/water separation was analyzed.In addition,we further explored the separation performances of the as-prepared membrane.The results revealed that the surface energy was effectively reduced and the surface roughness was significantly enhanced with the introduction of polyethylene wax(PEW)and PTFE,endowing the as-prepared membrane with superhydrophobicity and superoleophilicity.Importantly,the superhydrophobic and superoleophilic PPS microfiber membrane was effective for separating a wide range of oil/water mixtures solely by the driving of gravity.The separation efficiency was up to 99.5% and the highest oil flux was about 5190 L m-2 h-1.What is more,this PPS membrane also possessed rubust reusability.(2)By means of a simple and facile strategy of dip-coating followed by hot pressing,we fabricated a superhydrophilic and underwater superoleophobic PPS microfiber membrane with high porosity and diminutive pore size.The influence of modifier chitosan(CTS)concentration on the wettability of melt-blown PPS microfiber membranes was investigated.The mechanism of superhydrophilicity and underwater superoleophobicity was also revealed.Meanwhile,the effect of hot press on the pore diameter and porosity of the obtained membrane was evaluated.Additionally,we further explored the separation performance and mechanism for different kinds of emulsions.Owning to the hydrophilicity of CTS and some wrinkled nano-structure which was formed due to the cross-linking reaction of CTS,the modified membrane exhibited excellent superhydrophilicity and underwater superoleophobicity.The unique membrane structure with highly porosity and appropriate pore size,carefully regulated by hot pressing,could effectively intercept oil droplets and improve the separation efficiency and permeation flux.Furthermore,a ultrahigh permeation flux(about 2250 L m-2 h-1)on the basis of high separation efficiency(about 99.5%)was obtained under the sole driving of gravity along with excellent antifouling performance,robust reusability,and significant antibacterial activity. |
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