Abe Kohei, Inasawa Susumu
Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
Department of Applied Physics and Chemical Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
Langmuir. 2021 Jan 12;37(1):219-229. doi: 10.1021/acs.langmuir.0c02800. Epub 2020 Dec 29.
We have investigated the effect of buckling of particle-stabilized water droplets on the drying kinetics. Particle-stabilized water droplets in an oil phase were prepared and the shrinking modes of the droplets during drying were controlled by the wettability of the particles. We obtained water droplets with and without buckling and used them in drying experiments. The drying times were comparable when the droplets were fully immersed in a thick oil layer. However, when the thickness of the oil layer was smaller than the droplet diameter, the buckled droplets showed faster drying. Observation of the reflection images around the droplets suggested that the buckled droplets preferentially shrank in the height direction, while the droplets without buckling isotropically shrank. Mathematical models that assumed diffusion of dissolved water molecules in the oil layer showed good agreement with the experimental data. The effective water-oil interfacial area was constant in the buckled droplets, whereas it shrank in the droplets without buckling. This would be a reason for the faster drying of the partially immersed buckled droplets. Particulate shells on liquid droplets could be used to enhance droplet drying.
我们研究了颗粒稳定的水滴屈曲对干燥动力学的影响。制备了油相中颗粒稳定的水滴，并通过颗粒的润湿性控制干燥过程中水滴的收缩模式。我们获得了有屈曲和无屈曲的水滴，并将它们用于干燥实验。当水滴完全浸没在厚油层中时，干燥时间相当。然而，当油层厚度小于水滴直径时，屈曲的水滴干燥得更快。对水滴周围反射图像的观察表明，屈曲的水滴优先在高度方向收缩，而无屈曲的水滴各向同性收缩。假设溶解的水分子在油层中扩散的数学模型与实验数据吻合良好。屈曲水滴中的有效水-油界面面积是恒定的，而无屈曲水滴中的有效水-油界面面积会收缩。这将是部分浸没的屈曲水滴干燥更快的一个原因。液滴上的颗粒壳可用于增强液滴干燥。
