Influence of particle size on extraction from a charged bed - toward liquid marble formation
Influence of particle size on extraction from a charged bed - toward liquid marble formation
复制标题
颗粒尺寸对从带电床萃取到液态大理石形成的影响
DOI：
10.1039/c9sm01467e
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发表时间：
2019
期刊：
影响因子：
3.4
通讯作者：
Wanless Erica J.
中科院分区：
文献类型：
--
作者：
Thomas Casey A.;Kasahara Moe;Asaumi Yuta;Lobel Benjamin T.;Fujii Syuji;Ireland Peter M.;Webber Grant B.;Wanless Erica J.
粒子间的相互作用及其物理性质对液体弹珠静电形成的影响尚不清楚。在这里，我们首先关注增加颗粒直径（假设为20至140 μm）对从接地悬浮水滴下带电粒子推进床中提取颗粒的便利性的影响。较大的颗粒直径增加了提取的便利性，由于颗粒间的凝聚力降低，增加了应用于颗粒床的电位。虽然颗粒的提取是液体大理石形成的关键步骤，但输送到液滴以及随后的涂层和液体的稳定也很重要。进一步的研究强调，由于颗粒直径越小，液体表面颗粒之间的间隙越小，颗粒的覆盖率越高，液体的稳定性也越好。在研究粒径的影响时，通过权衡滴床分离距离、应用势和涂层动力学三者之间的关系，提出了利用静电形成可控液大理岩的最佳条件。此外，利用最薄弱环节统计和断裂力学对实验数据进行了初步建模，以重点研究在静电存在下颗粒特性和可提取性之间的关系。该模型代表了在进行实验工作之前预测用于液体弹珠静电形成的粒子的适用性的一步。
The interactions between particles and the role of their physical properties are not well understood for the electrostatic formation of liquid marbles. Here we focus initially on the impact of increasing particle diameter (notionally 20 to 140 μm) on the ease of particle extraction from an advancing bed of charged particles beneath an earthed, suspended water droplet. A larger particle diameter increased the ease of extraction, due to decreased interparticle cohesion, with increased potential applied to the particle bed. Whilst particle extraction is a crucial step in liquid marble formation, transport to the droplet and subsequent coating and stabilisation of the liquid is also significant. Further investigation highlighted that the smaller particle diameters afforded increased liquid stabilisation due to increased coverage and smaller interstitial spaces between particles on the liquid surface. Optimal conditions for controllable liquid marble formation using electrostatics was postulated as a trade-off between drop-bed separation distance, applied potential and kinetics of coating when studying impact of particle size. Furthermore, preliminary modelling, utilising weakest-link statistics and fracture mechanics, of the experimental data was undertaken to focus on development of the relationship between particle properties and extractability in the presence of electrostatics. This model represents a step towards predicting the suitability of particles for use in the electrostatic formation of liquid marbles prior to undertaking experimental work.