| With the rapid development of China’s urbanization and industrialization, the air pollution has become a major problem in the current environmental pollution. Human life, transportation, construction, and other industries discharge a large amount of dust and soot. This is not only threat for human health, but also has a tremendous impact on the harmony of the natural environment. In January4,2014, the National Office for Disaster Reduction, Ministry of Civil Affairs Bulletin2013natural disaster, took first step to cope with the problems caused by fog and mist. Therefore, we design and prepare an effective method to solve the dust pollution in the air and filter it from the source material, which was a major issue for healthy livelihood.Traditional conventional filter material consisting of nonwoven filter material with micron size particles have a good filter performance, but lesser in the filtration performance especially for nano-scale particulate material. Electrospinning is a basic but powerful technique to fabricate materials in nano-to sub-micro scale level, thus firstly, polyacrylonitrile (PAN) dissolved in N-N, dimethyl formamide (DMF) was electrospun by adjusting the processing parameters of different concentrations of PAN nanofibrous membrane. The morphology of as-spun nanofibrous membranes were characterized by using FE-SEM. The filtration performance and the mechanical properties on the structure and morphology of PAN fibrous membranes were characterized and the optimum concentration of PAN (11wt%) was used for detailed investigation. Secondly, in order to overcome the weak mechanical properties and to increase the friction between the PAN fibrous membranes, polyurethane (PU) was added. By adjusting the ratio (PAN/PU2/2) of the nozzle, the mechanical properties of the fibrous membranes improved and have shown better resistance with high filtration performance. Finally, in order to broaden the application areas of PAN/PU fibrous membrane, we used chemically synthesized fluorinated polyurethane (FPU). By adjusting the concentrations of FPU within the PAN and PU respectively, as-spun membranes have shown excellent water and oil repellency. These superamphiphobic PAN/PU composite fibrous membranes were characterized to check their wettability and filtration performance. Experimental results have shown that when the content of the FPU added to1wt%, PAN/PU fibrous membrane has presented water contact angle up to154°, and oil contact angle up to151°. Additionally, by using bubble point method, such as an optical profilometry, the surface morphology and roughness were precisely measured.At last, according to the environment requirements, we chose different weight of fibrous membranes to assemble the membrane with actual filtration efficiency and pressure drop resistance requirements. When the fibrous membrane have weight about24g/m2, the filtration efficiency of aerosol particles of dust and oil was99.999,99.980%, respectively, The pressure drop was only116and117Pa (air flow rate of32L/min). In determining the weight of the fibrous membrane, we have investigated the relationship between the different membrane filters for their pressure drop and resistance properties, and when the air flow rate was up to90L/min, the filtration efficiency of the aerosol particles of dust and oil was99.981and99.956%, which still showed fine filtration. |
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