摘要： The self-coating process of solid particles over a liquid drop is important for the formation of a liquid marble. Generally, some external forces such as rolling or flipping are used to cover a drop by small particles. In this work, it is observed that flaky copper powders can spontaneously spread over the planar water surface and form a dense flat cluster with a fractal dimension of 2. Moreover, flaky copper powders can cover the water pendant and sessile drops spontaneously and rapidly. This powder-coated drop can roll on an inclined plane at a relatively high speed. However, spontaneous self-coating disappears for spheroidal copper powders. To explain our observations, the shape factors of particles are introduced into the spreading coefficient S for powders on the liquid surface. The flaky powders have the lowest shape factors and therefore spontaneous self-coating formation, with S > 0. The particle shape plays a critical role in the spontaneous self-coating process of solid particles over a liquid droplet. 出版日期： 2015-05-27 識別號： ISSN: 1744-683X 識別號： EISSN: 1744-6848 識別號： DOI: 10.1039/c5sm00332f
