Filtration of nanosized particles with different shape on oil coated fibres
Filtration of nanosized particles with different shape on oil coated fibres
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DOI：
10.1016/j.jaerosci.2007.09.003
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发表时间：
2007-12-01
影响因子：
4.5
通讯作者：
Braddock, Roger D.
中科院分区：
文献类型：
--
作者：
Boskovic, Lucija;Agranovski, Igor E.;Braddock, Roger D.
在我们先前的工作中，已经表明，与具有与PSL颗粒相同的电迁移率的立方氧化镁（MgO）颗粒相比，完美球形的聚苯乙烯胶乳（PSL）颗粒具有更高的过滤效率。这种差异归因于初始碰撞后球形和立方体颗粒沿着纤维表面运动的不同性质。在接触纤维表面之后和静止之前，球形颗粒可以滑动或滚动，而立方体颗粒可以滑动或翻滚。在翻滚过程中，颗粒和纤维之间的接触面积显著变化，从而影响反弹概率，而对于球体，颗粒轨迹的任何点的接触面积保持相同。在该项目中，聚丙烯过滤器涂有一层薄薄的矿物油，用于吸收能量，并分别最大限度地减少碰撞后沿纤维沿着的颗粒运动。在10和20 cm/s的过滤速度下，测量了粒径在50- 300 nm范围内的球形PSL和立方体MgO颗粒的过滤效率。发现无论形状如何，两种颗粒类型都具有非常相似的过滤效率。理论预测与我们的实验结果符合得很好。因此，可以得出这样的结论：油涂层使初始碰撞后颗粒沿纤维沿着运动的量最小化，使得所有颗粒形状的结果相似。(c)2007爱思唯尔有限公司保留所有权利。
In our previous work it has been shown that perfectly spherical polystyrene latex (PSL) particles have higher filtration efficiency compared to cubic magnesium oxide (MgO) particles of the same electrical mobility as PSL particles. This disparity was ascribed to the different nature of motion of the spherical and cubic particles along the fibre surface, following the initial collision. After touching the fibre surface and before coming to rest, the spherical particles could either slide or roll compared to the cubic ones, which could slide or tumble. During tumbling, the area of contact between the particle and the fibre changes significantly, thus affecting the bounce probability, whilst for the spheres, the area of contact remains the same for any point of particle trajectory. In this project, the polypropylene filter was coated with a thin layer of mineral oil that was used to absorb the energy and, respectively, to minimize particle motion along the fibre after collision. The filtration efficiency of spherical PSL, and cubic MgO particles was measured in the size range of 50-300nm, for filtration velocity of 10 and 20cm/s. It was found that, regardless of shape, both particle types have very similar filtration efficiency. The theoretical predictions are in good agreement with our experimental results. Therefore, the conclusion can be drawn that the oil coating minimizes the amount of particle motion along the fibre after initial collision, making results for all particle shapes similar. (c) 2007 Elsevier Ltd. All rights reserved.