wileyonlinelibrary.comWhile considerable progress of 2D deformation of SPHs has been achieved, [15][16][17][18][19][20][21][22][23] the realization of 3D or even more complex deformation still remains a significant challenge. Currently, there are two main approaches to achieve 3D complex deformations/movements of SPHs by imposing external nonuniform stimuli [24,25] or through the preparation of internal anisotropic hydrogels. [26,27] Due to the difficulty of applying most of the nonuniform external stimuli precisely onto a SPHs system, an alternative strategy of fabricating macroscopically anisotropic SPHs (MA-SPHs) has been explored as the popular way to realize complex 3D deformation. [26,27] These SPHs can accomplish diverse complex deformations directly under uniform stimuli owing to the heterogeneous responsiveness of anisotropic structures.Complex 3D deformation of the MA-SPHs could be achieved through the fabrication of differential cross-linking density [28][29][30] or a local secondnetwork [31][32][33][34][35] and subsequently applying external stimuli inside the hydrogels. For example, Sharon and co-workers have reported an early example to prepare a 2D anisotropic hydrogel sheet with laterally nonuniform cross-linking density to realize the 3D buckling or wrinkling. [28] Hayward and co-workers have introduced cross-linked stimulus-responsive polymers with UV-induced patterning to fabricate 2D hydrogel sheets with precisely controllable 3D bucklings. [29] Using a similar strategy, Wu et al. have developed an anisotropic 2D gel sheet with a tunable second-network to achieve 3D spiralings or curlings. [31] Besides UV cross-linking, an "electrically assisted ionoprinting" technique could also be utilized to form a local second-network and to attain 3D complex deformations. [32,34] Despite the recent progress of 3D complex deformation of MA-SPHs, the lack of remote-controllability during the deformation process strongly limits their application in some special fields, where solution-wide changes or invasive wires or electrodes are not permitted.With excellent photothermal conversion efficiency, [36] graphene sheets are well known as good candidates to obtain remote-controllable light-responsive deformations. However, they cannot be homodispersed in hydrogel directly because of their hydrophobic nature. Alternatively, graphene oxide sheets (GOs) can be well dispersed in hydrogels and can be reduced in situ using UV irradiation to attain reduced GOs (RGOs). Therefore, remote-controllable light-responsive deformations of As one of the most promising smart materials, stimuli-responsive polymer hydrogels (SPHs) can reversibly change volume or shape in response to external stimuli. They thus have shown promising applications in many fields. While considerable progress of 2D deformation of SPHs has been achieved, the realization of 3D or even more complex deformation still remains a significant challenge. Here, a general strategy towards designing multiresponsive, macroscopically anisotropic SPHs (MA-SPHs) with th...

In studies of epoxy/graphene oxide (GO) nanocomposites, organic solvents are commonly used to disperse GO, and vigorous mechanical processes and complicated modification of GO are usually required, increasing the cost and hindering the development and application of epoxy nanocomposites. Here, we report a green, facile, and efficient method of preparing epoxy/GO nanocomposites. When triglycidyl para-aminophenol (TGPAP), a commercially available glycidyl amine epoxy resin with one tertiary amine group per molecule, is used as both the surface modifier and phase transfer agent of GO, GO can be directly and rapidly transferred from water to diglycidyl ether of bisphenol A and other types of epoxy resins by manual stirring under ambient conditions, whereas GO cannot be transferred to these epoxy resins in the absence of TGPAP. The interaction between TGPAP and GO and the effect of the TGPAP content on the dispersion of GO in the epoxy matrix were investigated systematically. Superior dispersion and exfoliation of GO nanosheets and remarkably improved mechanical properties, including tensile and flexural properties, toughness, storage modulus, and microhardness, of the epoxy/GO nanocomposites with a suitable amount of TGPAP were demonstrated. This method is organic-solvent-free and technically feasible for large-scale preparation of high-performance nanocomposites; it opens up new opportunities for exploiting the unique properties of graphene or even other nanofillers for a wide range of applications.

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A highly efficient phosphorous-containing flame retardant for PLA is synthesized from plant-derived diphenolic acids.