Strong, Shape-Memory Lignocellulosic Aerogel via Wood Cell Wall Nanoscale Reassembly

Abstract

Polymer shape-memory aerogels (PSMAs) are prospects in various fields of application ranging from aerospace to biomedicine, as advanced thermal insulators, actuators, or sensors. However, the fabrication of PSMAs with good mechanical performance is challenging and is currently dominated by fossil-based polymers. In this work, strong, shape-memory bio-aerogels with high specific surface areas (up to 220 m2/g) and low radial thermal conductivity (0.042 W/mK) were prepared through a one-step treatment of native wood using an ionic liquid mixture of [MTBD]+[MMP]−/DMSO. The aerogel showed similar chemical composition similar to native wood. Nanoscale spatial rearrangement of wood biopolymers in the cell wall and lumen was achieved, resulting in flexible hydrogels, offering design freedom for subsequent aerogels with intricate geometries. Shape-memory function under stimuli of water was reported. The chemical composition and distribution, morphology, and mechanical performance of the aerogel were carefully studied using confocal Raman spectroscopy, AFM, SAXS/WAXS, NMR, digital image correlation, etc. With its simplicity, sustainability, and the broad range of applicability, the methodology developed for nanoscale reassembly of wood is an advancement for the design of biobased shape-memory aerogels.

Wood-based electrolyte with reversible phase transition for smart thermal-shutdown self-protection

“…The circular arc in the scattered image was "short and fat" with an aspect ratio of 1.56. 38 A signal appeared in 1D scattering line proles at ∼0.9 nm −1 (Fig. 4h), which corresponded to the face-centered cubic (FCC) structure of PEO-PPO-PEO chains with an intercorrelation length of 7.1 nm (Fig.…”

Recent advances in wood-based electrode materials for supercapacitors

“…Reproduced with permission. 169 Copyright 2023, American Chemical Society. (d) Biologically enzyme-assisted method.…”

“…The chemical component of wood pretreated by delignification is mainly cellulose I (the existing form of natural cellulose). When it meets some green solvents like LiCl/DMAc, 174 alkali hydroxide-urea, 175 and ionic liquids, 169,176 the ordered cellulose I nanofibers on the cell wall surface are dissolved by regulating the reaction time, temperature, and other factors. The dissolved cellulose can be further regenerated through a phase conversion process (from cellulose I to cellulose II) in a coagulation bath and the cellulose molecular chains entangle with each other via strong hydrogen bonding.…”

“…(c) Dissolution-regeneration by ion liquid solvents. Reproduced with permission 169. Copyright 2023, American Chemical Society.…”

Strong, Lightweight, and Shape‐Memory Bamboo‐Derived All‐Cellulose Aerogels for Versatile Scaffolds of Sustainable Multifunctional Materials

“…[ 37 ] Due to the in situ assembly of RC nanonetwork within the cell wall, the aerogel exhibits remarkable water‐responsive shape memory properties. [ 38 ] Nonetheless, the strength‐to‐density of the woody aerogel is still limited by the inherently oriented channels and compact wall layers of bulk wood. To the best of our knowledge, there have been scarce reports on constructing ACAs using partially dissolved CMFs, which feature more flexible structural and mechanical controllability.…”