Bio-inspired functional wood-based materials – hybrids and replicates

Abstract

Wood is a CO 2 storing material from renewable resoures with excellent mechanical properties and a sophisticated hierarchical structure from the nanoscale of cel l wall polymers up to the macroscale of tree size. In recent years, one can observe an increasing research interest in modifying and functionalising wood cell and cell wall assemblies as well as cell wall components. In this context, three fundamental approaches aiming at developing novel and advanced bioinspired and bio-based functional materials can be identified. At the level of bulk wood, this review will cover two research directions of wood functionalisation which have in common the utilisation of the hierarchical structure at different length scales, but differ in terms of the preservation of the organic scaffold of the w ood cel l wall. In those protocols that modify and functionalise wood cell walls with the emphasis on retaining their structural integrity, hybrid materials leading to polymer-or mineral-related wood products are developed. In the second wood functionalisation approach , the hierarchical structure of wood is used as a template to engineer wood-derived inorganic non-metallic materials. The third approach is at the level of cell wall components, where bio-based materials from wood cellulose nanofibres (CNF) are discussed. The use of CNF allows for designing structures with different porosities and new combinations of anisotropic properties beyond the predetermined hierarchical structure of wood. The review will cover fundamental aspects and various protocols for the three to date surprisingly separately treated approaches with a focus on synthesis procedures and characterisation of the modified materials with respect to the targeted functionalisation as

Lytic polysaccharide monooxygenases disrupt the cellulose fibers structure

“…Cellulose is the most abundant natural biopolymer on Earth, composed of linear β-(1–4)-linked D-glucopyranose chains tightly packed, that are highly recalcitrant to enzymatic hydrolysis. This limits their cost-effective degradation and it is the main bottleneck for the development of sustainable processes including conversion of plant biomass to biofuels1 and production of nanocellulose-based materials2. Lytic polysaccharide monooxygenases (LPMOs) are considered as a breakthrough in the enzymatic degradation of cellulose3 because they oxidatively cleave glycosidic linkages that render the substrate more susceptible to hydrolysis by conventional cellulases.…”

Lasing from Organic Dye Molecules Embedded in Transparent Wood

“…[13][14][15] Transparent wood features light weight, modification accessibility, excellent mechanical performance, and structural anisotropy introduced by aligned hollow cells. [16,17] Optical transparency of TW is the most unique property, which extends its applications in various fields, including biosciences, lighting, building industry, and others. [17][18][19] Although this material (TW) is relatively new, it has already been tested for potential applications in optics, but so far only for implementation in passive photonic components.…”

Efficacy of Hydrophobic Coatings in Protecting Oak Wood Surfaces during Accelerated Weathering

“…The water synergistically interacts with solar radiation and causes atmospheric degradation of the wood surface [4][5][6], as well as dimensional changes and crack formation [7]. Modification in the form of hydrophobization can increase the natural durability of wood against biotic and abiotic damages on its exterior [8,9]. Modifications changing the properties of wood in its entire volume, such as thermal treatment or acetylation, are a frequent treatment method [10,11].…”