Programmable Local Orientation of Micropores by Mold‐Assisted Ice Templating

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.

Lyophilization‐Free Engineering of Polyelectrolyte Monolith by an Ice‐Dissolving‐Complexation Method

“…[10][11][12] Aqueous solutions or dispersions containing polymers and complementary building blocks are frozen to form ice crystal templates embedded within the monolith. [13][14][15][16][17] There are significant interests in modulating the nucleation, growth, shapes, sizes, and hierarchy of ice templates, [18][19][20][21][22][23] leading to emerging functionalities such as high strength materials, [24][25][26][27] sustainable composites, [28,29] solar-thermal evaporators, [30] etc. Microstructures of and gels.…”

Wires with Continuous Sabal Leaf‐Patterned Micropores Constructed by Freeze Printing for a Wearable Sensor Responsible to Multiple Deformations

“…The 3D orientation of the local temperature gradient determines the growing direction of ice crystals during the printing of slurry and thus the resulted inner structures in the wire (Figure S5, Supporting Information). [ 34 ] To better under the freezing process, the heat transfer was simulated. Once the slurry gets into contact with the cold finger, the first contact point (point A in Figure 3c) quickly colds down.…”

“…[ 29–31 ] Moreover, ice templating methods have the capability to program the size, distribution and orientation of pores, which offers us a great opportunity to fabricate designed conductive porous structures for wearable sensors. [ 20,31,34,35 ]…”

“…[29][30][31] Moreover, ice templating methods have the capability to program the size, distribution and orientation of pores, which offers us a great opportunity to fabricate designed conductive porous structures for wearable sensors. [20,31,34,35] Herein, we report a technique termed freeze printing that enables the fabrication of round wire with long-rangeThe design of porous structure in wearable sensors is very important for the detection of mechanical signals. However, it remains challenging to construct a porous structure capable of detecting all kinds of mechanical signals.…”

“…[29][30][31] Moreover, ice templating methods have the capability to program the size, distribution and orientation of pores, which offers us a great opportunity to fabricate designed conductive porous structures for wearable sensors. [20,31,34,35] Herein, we report a technique termed freeze printing that enables the fabrication of round wire with long-range…”