Key Laboratory of Advanced Light Conversion Materials and Biophotonics, Department of Chemistry, Renmin University of China, Beijing, 100872, China.
Small. 2022 Aug;18(33):e2203355. doi: 10.1002/smll.202203355. Epub 2022 Jul 24.
Droplet impact is a ubiquitous natural phenomenon that has been widely utilized to inspire and facilitate many industrial applications. Compared to the widely studied water droplet impact onto identical liquid surfaces, the water droplet impact onto an oil layer floating on a water bath (OLW) receives far less attention and its potential application has never been exploited. Herein, the process of water droplet impact onto the OLW is investigated with emphasis on the metastable states and potential applications. It is found that the dramatic deformation of the oil-water interface caused by the water droplet impact leads to two metastable states: oil in water in oil in water (O/W/O/W) and oil in water in oil (O/W/O). Through the subsequent introduction of gelation process, the metastable states can be frozen into floating hydrogel beads with similar shape to the roly-poly toys, which are attempted in gastric retentive drug delivery and algae bloom control. Specifically, the floating hydrogel beads perform well in gastric retentive drug delivery in vitro due to their inherent slow-release properties and floating capability. In addition, the floating hydrogel beads loading photocatalysts can capture more sunshine, and exhibit high photocatalytic efficiency, which is thus responsible for efficient algae bloom control.
液滴撞击是一种普遍存在的自然现象，已被广泛应用于激发和促进许多工业应用。与广泛研究的水滴撞击相同液体表面相比，水滴撞击浮在水层上的油层（OLW）受到的关注要少得多，其潜在应用从未得到过开发。本文重点研究了水滴撞击 OLW 的过程，以及关注了亚稳状态及其潜在应用。研究发现，水滴撞击引起的油水界面剧烈变形导致了两种亚稳状态：油包水包油包水（O/W/O/W）和油包水（O/W/O）。通过随后引入的凝胶化过程，亚稳状态可以被冻结成与毛毛虫玩具类似形状的漂浮水凝胶珠，这在胃滞留药物递送和藻类水华控制中进行了尝试。具体来说，由于漂浮水凝胶珠具有固有的缓释特性和漂浮能力，因此在体外胃滞留药物递送中表现良好。此外，负载光催化剂的漂浮水凝胶珠可以捕获更多的阳光，并表现出高的光催化效率，从而有效地控制藻类水华。
