Department of Mechanical and Aerospace Engineering, University of California-Irvine, Irvine, CA, 92697, USA.
NG Next, Northrop Grumman Aerospace Systems, Redondo Beach, CA, 90278, USA.
Sci Rep. 2017 Sep 5;7(1):10465. doi: 10.1038/s41598-017-10791-3.
Delivering liquid through the void spaces in porous metals is a daunting challenge for a variety of emerging interface technologies ranging from battery electrodes to evaporation surfaces. Hydraulic transport characteristics of well-ordered porous media are governed by the pore distribution, porosity, and morphology. Much like energy transport in polycrystalline solids, hydraulic transport in semi-ordered porous media is predominantly limited by defects and grain boundaries. Here, we report the wicking performances for porous copper inverse opals having pore diameters from 300 to 1000 nm by measuring the capillary-driven liquid rise. The capillary performance parameter within single crystal domain (K /R = 10 to 10 µm) is an order of magnitude greater than the collective polycrystal (K /R = ~10 to 10 µm) due to the hydraulic resistances (i.e. grain boundaries between individual grains). Inspired by the heterogeneity found in biological systems, we report that the capillary performance parameter of gradient porous copper (K /R = ~10 µm), comparable to that of single crystals, overcomes hydraulic resistances through providing additional hydraulic routes in three dimensions. The understanding of microscopic liquid transport physics through porous crystals and across grain boundaries will help to pave the way for the spatial design of next-generation heterogeneous porous media.
在各种新兴界面技术中，通过多孔金属的空隙输送液体是一项艰巨的挑战，这些技术的应用范围从电池电极到蒸发表面。有序多孔介质的液压传输特性受孔径分布、孔隙率和形态的控制。就像多晶体内的能量传输一样，半有序多孔介质中的液压传输主要受到缺陷和晶界的限制。在这里，我们通过测量毛细驱动液体上升来报告具有 300 至 1000nm 孔径的多孔铜反蛋白石的吸液性能。由于液压阻力（即单个晶粒之间的晶界），单晶域内的毛细性能参数（K / R = 10 至 10 微米）比多晶域（K / R = ~10 至 10 微米）大一个数量级。受生物系统中发现的异质性的启发，我们报告梯度多孔铜（K / R = ~10 微米）的毛细性能参数可与单晶相媲美，通过在三维空间提供额外的液压路径来克服液压阻力。通过多孔晶体和晶界进行微观液体传输物理的理解将有助于为下一代非均质多孔介质的空间设计铺平道路。
