Chebbi Rachid
Department of Chemical Engineering, American University of Sharjah, Sharjah 26666, United Arab Emirates.
ACS Omega. 2021 Feb 5;6(7):4649-4655. doi: 10.1021/acsomega.0c05341. eCollection 2021 Feb 23.
Spreading over porous substrates occurs in several processes including printing, cleaning, coating, and manufacturing of ceramic structures. For small drops, viscous and capillary forces are ultimately the predominant forces. The process typically undergoes three phases: a first stage in which the droplet spreads, a second phase in which the area of contact with the solid substrate nearly remains constant, and a third stage in which the droplet retracts with its volume reaching zero finally. The objective of the investigation is to find the dynamics of spreading and absorption of the droplet using fundamentals while making relevant approximations to account for both radial and vertical dynamics. The proposed model requires minimal computational work. The results are compared with the published experimental data for the perfect wetting case, and are found to be in good agreement with detailed published experimental data for both droplet dynamics and dynamics of penetration in the porous substrate.
液滴在多孔基材上的铺展发生在多个过程中，包括印刷、清洁、涂层以及陶瓷结构的制造。对于小液滴而言，粘性力和毛细力最终是主要作用力。该过程通常经历三个阶段：第一阶段液滴铺展，第二阶段与固体基材的接触面积几乎保持不变，第三阶段液滴回缩，其体积最终达到零。研究的目的是利用基本原理并进行相关近似以考虑径向和垂直动力学，从而找出液滴铺展和吸收的动力学。所提出的模型所需的计算量最小。将结果与已发表的完全润湿情况下的实验数据进行比较，发现对于液滴动力学和在多孔基材中的渗透动力学，该结果与已发表的详细实验数据吻合良好。
