Fig. 1

Schematic illustrations of the formation of SNPP hydrogel. a Ag@BACA nanocomposite linked by the RS-Ag coordination bonds. b When the BACA molecules were adsorbed onto the silver NPs, the S–S cleavage occurred. Under UV light, the cleaved BACA molecules on the surface of silver NPs were rearranged. With the help of the hydrophobically lamellar assembly of the Ag@BACA nanocomposites, the cofacially arranged Ag/PAM lamellae were formed by a UV light induced polymerization. c Upon prolonging the UV irradiation, the anisotropic hydrogel was fabricated by propagating the PAM chains around the Ag/PAM lamellae. d The anisotropic hydrogel shows actuating ability when exposed in poor solvent of PAM chains. e Molecular structure of the used co-monomers