Physics of Fluids Group, Max-Planck-Center Twente for Complex Fluid Dynamics, Mesa+ Institute, and J. M. Burgers Centre for Fluid Dynamics, Department of Science and Technology, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
School of Chemical Engineering & Materials Science, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, 06974, Korea.
Nat Commun. 2019 Jan 29;10(1):478. doi: 10.1038/s41467-019-08385-w.
The assembly of colloidal particles from evaporating suspension drops is seen as a versatile route for the fabrication of supraparticles for various applications. However, drop contact line pining leads to uncontrolled shapes of the emerging supraparticles, hindering this technique. Here we report how the pinning problem can be overcome by self-lubrication. The colloidal particles are dispersed in ternary drops (water, ethanol, and anise-oil). As the ethanol evaporates, oil microdroplets form ('ouzo effect'). The oil microdroplets coalesce and form an oil ring at the contact line, levitating the evaporating colloidal drop ('self-lubrication'). Then the water evaporates, leaving behind a porous supraparticle, which easily detaches from the surface. The dispersed oil microdroplets act as templates, leading to multi-scale, fractal-like structures inside the supraparticle. Employing this method, we could produce a large number of supraparticles with tunable shapes and high porosity on hydrophobic surfaces.
从蒸发的悬浮液滴中组装胶体颗粒被视为制造各种应用的超粒子的通用途径。然而，液滴接触线钉扎导致新兴超粒子的形状不受控制，从而阻碍了这种技术。在这里，我们报告了如何通过自润滑克服这个问题。胶体颗粒分散在三元液滴（水、乙醇和茴香油）中。随着乙醇的蒸发，油微滴形成（“ouzo 效应”）。油微滴聚合并在接触线处形成油环，使蒸发的胶体液滴悬浮（“自润滑”）。然后水蒸发，留下多孔的超粒子，它很容易从表面脱落。分散的油微滴作为模板，在超粒子内部形成多尺度的、类似分形的结构。使用这种方法，我们可以在疏水性表面上大量生产具有可调形状和高孔隙率的超粒子。
Zotero 插件
