Synthesis and evaluation of straight and bead-free nanofibers for improved aerosol filtration
Synthesis and evaluation of straight and bead-free nanofibers for improved aerosol filtration
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DOI：
10.1016/j.ces.2015.07.038
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发表时间：
2015-12-01
影响因子：
4.7
通讯作者：
Okuyama, Kikuo
中科院分区：
文献类型：
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作者：
Balgis, Ratna;Kartikowati, Christina W.;Okuyama, Kikuo
以聚丙烯腈为前驱体，在二甲甲酰胺中加入碘化钾，采用静电纺丝法合成了直线型和无珠状纳米纤维。将直径为36.5 ~ 300 nm的纳米和亚微米纤维静电纺丝在微纤维垫表面作为基滤，形成强多层滤膜。通过调整静电纺丝气氛（即温度和湿度）以及前驱体溶液中聚丙烯腈和碘化钾的浓度来控制纤维的尺寸。采用直径为100 nm的单分散气溶胶颗粒进行气溶胶过滤试验，同时测量了所制备的多层过滤器的压降。有趣的是，由直径小于100 nm的纳米纤维组成的过滤器沉积在基础过滤器上，压降速率降低。在这种情况下，压降比连续流型的预期更缓慢，主要是由于滑移流的影响。由于纳米纤维越薄，传质边界层的厚度越大，因此这些过滤器的过滤效率几乎不变。纤维直径的进一步减小导致流动状态进入自由分子状态。(C) 2015 Elsevier Ltd.版权所有。
Straight and bead-free nanofibers were synthesized via electrospinning by adding potassium iodide to a precursor containing polyacrylonitrile dissolved in dimethylformamide. Nano- and submicron-fibers with diameters of 36.5-300 nm were electrospun on the surface of a microfiber mat as the base filter to form a strong multilayer filter. The size of the fibers was controlled by adjusting the electrospinning atmosphere (i.e., temperature and humidity) and polyacrylonitrile and potassium iodide concentrations in the precursor solution. The pressure drop of the prepared multilayer filters was measured simultaneously in an aerosol filtration test using monodispersed aerosol particles of diameter 100 nm. Interestingly, the rate of pressure drop was reduced for filters composed of nanofibers with a diameter of less than 100 nm deposited on the base filter. In this case, the pressure drop was more gradual than was expected for a continuous flow pattern, mainly because of the slip flow effect. Because the thickness of the boundary layer for mass transfer is greater when nanofibers are thinner, the filtration efficiency of these filters was almost constant. Further reduction of the fiber diameter leads to the flow condition entering the free-molecular regime. (C) 2015 Elsevier Ltd. All rights reserved.