Programmable Local Orientation of Micropores by Mold‐Assisted Ice Templating
Xiaohong Zhou, Liang Yin, Baisong Yang, Chuyang Chen, Wenhui Chen, Yu Xie, Xichen Yang, Jonathan T. Pham, Sheng Liu, Longjian Xue
Abstract
Pore geometry plays a crucial role in determining the properties and functions of porous materials. Various methods have been developed to prepare porous materials that have randomly distributed or well-aligned pores. However, a technique capable of fine regulation of local pore orientation is still highly desired but difficult to attain. A technique, termed mold-assisted ice templating (MIT), is reported to control and program the local orientation of micropores. MIT employs a copper mold of a particular shape (for instance a circle, square, hexagon, or star) and a cold finger to regulate the 3D orientation of a local temperature gradient, which directs the growth of ice crystals; this approach results in the formation of finely regulated patterns of lamellar pore structures. Moreover, the lamellar thickness and spacing can be tuned by controlling the solution concentration.