Effect of wetting and drying on meniscus structures in hydrophobic sands
Effect of wetting and drying on meniscus structures in hydrophobic sands
复制标题
湿润和干燥对疏水性砂中弯月面结构的影响
DOI：
10.1051/e3sconf/202019503040
复制
发表时间：
2020
影响因子：
--
通讯作者：
Karatza Z
中科院分区：
文献类型：
--
作者：
Karatza Z
当颗粒涂有源自植物的疏水性有机化合物时或暴露在非常高的温度下时，疏水性土壤可以自然发生，或者如果在实验室中用受污染的水或化学品处理，则可以人为地发生。疏水性土壤可以抵抗水渗透，与优先流相关，并可能导致地表径流和土壤侵蚀增加。对不饱和疏水土壤的传统理解表明，由于接触角 > 90°，土壤颗粒之间应形成凸水弯月面，从而形成正水压。然而，实验结果并不支持这一理论。这项工作的目的是研究疏水砂样本中弯月面结构的变化，以及砂对湿润和干燥循环的总体响应。将非常均匀的细硅砂与二甲基二氯硅烷混合以产生防水性。展示了环境扫描电子显微镜捕获的连续图像，以检查沙子在两个不同的干燥和润湿循环中的响应。初步结果表明，尽管接触角较高，但砂粒的非球形性质可以防止或阻碍凸液桥的形成。相反，水滴似乎只能通过水滴聚结来膨胀，这可以防止结构在干燥时收缩。
Hydrophobic soils can occur either naturally when particles are coated with plant-derived hydropho-bic organic compounds or if exposed to very high temperatures, or artificially if treated with contaminated water or chemicals in the laboratory. Hydrophobic soils can resist water infiltration, are associated with preferential flow and may lead to increased surface runoffand soil erosion. Traditional understanding of unsaturated hy-drophobic soils suggests that convex water menisci, and so positive water pressures, should form between soil particles, due to contact angles > 90◦. However, experimental results do not support this theory. The objective of this work was to study the changes in meniscus structures in hydrophobic sand specimens, as well as the overall response of the sand to wetting and drying cycles. A very uniform, fine silica sand was mixed with Dimethyldichlorosilane to induce water repellence. Successive images captured in an environmental scanning electron microscope are presented, to examine the response of the sand in two distinct drying and wetting cycles. Preliminary results show that the non-spherical nature of the sand particles prevent or hinder the formation of convex liquid bridges, despite the high contact angles. Rather, water droplets appear to expand only through droplet coalescence, which prevents structures from contracting on drying.
DOI：
--
发表时间：
2016
期刊：
影响因子：
--
作者：
C. Beckett;A. Fourie;D. Toll
通讯作者：
D. Toll
影响因子：
5.8
作者：
S. Lourenço;D. Gallipoli;C. Augarde;D. Toll;P. Fisher;A. Congreve
通讯作者：
S. Lourenço;D. Gallipoli;C. Augarde;D. Toll;P. Fisher;A. Congreve