Fig. 1: Fabrication of CCAP hydrogel.

a, Schematic illustration of the fabrication of the CCAP hydrogel by the combined directional freezing assembly and two-stage in situ polymerization process, that is, cryopolymerization at −18 °C for 12 h and subsequent polymerization at room temperature for 2 h. AM, MBAA and TEMED are used as the monomer, crosslinker and catalyst, respectively. b, Schematic of structural changes during the cryopolymerization process. In stage 1, the localized AgNW network in the compartmental wall was distorted under the uneven tension resulting from the phase transformation of the tightly and loosely bound water around the AgNW surfaces. Stabilized by the simultaneous in situ polymerization, a porous structure was produced in stage 2. c, Thawing of a large area of ice induced neighbouring lamellae to grow together in further polymerization at room temperature, forming an interconnected high-tortuosity network.