Gopu Maheshwar, Rathod Sachin, Namangalam Uma, Pujala Ravi Kumar, Kumar S Sunil, Mampallil Dileep
Department of Physics, Indian Institute of Science Education and Research, Mangalam, 517507 Tirupati, India.
Langmuir. 2020 Jul 21;36(28):8137-8143. doi: 10.1021/acs.langmuir.0c01084. Epub 2020 Jul 8.
Evaporation of colloidal drops on horizontal surfaces deposits the contained particles at the drop-edge producing radially symmetric ring-like stains. The symmetry in the particle deposition is broken when the drop is placed on a tilted surface due to the influence of gravity on the suspended particles and the drop itself. Using extremely small drops generated by electrospray, we explore cases where different mechanisms of particle transport dominate. We show that the asymmetric residues are formed as the gravity-induced effects compete with the capillary flow. Our results give a broad insight into the pattern formation of evaporating inclined drops.
胶体液滴在水平表面上蒸发时，会将所含颗粒沉积在液滴边缘，形成径向对称的环状污渍。当液滴放置在倾斜表面上时，由于重力对悬浮颗粒和液滴本身的影响，颗粒沉积的对称性会被打破。利用电喷雾产生的极小液滴，我们探索了不同颗粒传输机制起主导作用的情况。我们表明，不对称残留物是在重力诱导效应与毛细流相互竞争时形成的。我们的结果为蒸发倾斜液滴的图案形成提供了广泛的见解。
