Green synthesis of multifunctional wood-based eutectogels via initiator-free solar polymerization

Gels, as appealing materials for soft electronic devices, often face the great challenge of inherent defects in the solvents, inducing their weak mechanical performance, environmental instability, and limited applications. Herein, multifunctional wood-based eutectogels are developed in the presence of green polymerizable deep eutectic solvents (PDESs, consisting of choline chloride, ChCl; acrylic acid, AA; acrylamide, AM), and reinforced by the tannic acid-encapsulated wood skeleton (TA@WS). The study highlights a green synthesis strategy of solar polymerization without using any chemical initiators or cross-linkers, and overcomes the critical limitations of environmental instability and poor mechanical performance of gel materials. In particular, the developed wood-based eutectogels simultaneously show a high tensile strength of 52.8 MPa and environmental tolerance from −80 ℃∼200 ℃, surpassing most of the reported wood-based gel materials. Moreover, the synergy between TA@WS and PDES endows the wood-based eutectogels with additional self-healing performance, adhesion properties, easy-recyclability, heat-insulation, and electrical conductivity. Benefitting from these features, the developed multifunctional wood-based eutectogels hold great promise in advanced energy applications such as wearable sensors, recyclable materials and smart house construction materials.