Rapid synthesis of mechanically robust and environmentally tolerant eutectogels reinforced by aligned cellulose fibers from wood.

The development of high-performance biomass-derived soft materials is crucial for advancing sustainable alternatives to petroleum-based systems, and bio-based composite gel materials became a favorable choice with their biocompatibility and sustainability. However, it still remains a challenge to fabricate bio-based composite gels with favorable mechanical performance and environmental stability via a simple and energy-efficient approach. Herein, a wood-based composite gel (WCG) was fabricated by compositing cellulose fibers with polymerizable deep eutectic solvents (PDES), consisting of choline chloride (ChCl), acrylic acid (AA) and acrylamide (AM) under a fast process of UV radiation within 2 min. The naturally oriented structure of the aligned cellulose fibers reinforced WCG with a high mechanical strength of 62.51 ± 4.41 MPa, while the multiple hydrogen bond networks contribute to the great toughness (7.77 ± 0.34 MJ m), simultaneously exhibiting a high tensile strain of 19.91 ± 2.39 %. Additionally, WCGs exhibited environmental stability (-60-100 °C) to overcome the critical limitations of conventional gel materials in low mechanical properties due to loss of solvents. Integrated with sensing performance and thermal-insulation, flame retardant, WCGs enabled human motion detection in smart building systems, showing a promising future for the rapid preparation of high-performance, sustainable bio-based efficient smart materials.