Enhancement of the heat conduction performance of boron nitride/cellulosic fibre insulating composites - Fig 5

<p>The effects of filler loading on (a) Relative permittivity and dielectric loss angle tangent (b) breakdown strength (c) Volume resistivity.</p

Enhancement of the heat conduction performance of boron nitride/cellulosic fibre insulating composites - Fig 4

<p>Schematic diagram of the filler distribution within the BN/cellulosic fibre composite (a) No heat-conductive pathway at low filler loading (b) Heat-conductive pathways gradually formed at high filler loading (c) More compact and integrated heat-conductive pathways with dual-size filler.</p

Enhancement of the heat conduction performance of boron nitride/cellulosic fibre insulating composites - Fig 6

<p>SEM images of (a) surface and (b) cross-section of composite with 11.5wt% filler loading; SEM images of (c) surface and (d) cross-section of composite with 41.1wt% filler loading.</p

Enhancement of the heat conduction performance of boron nitride/cellulosic fibre insulating composites - Fig 2

<p>(a)FTIR spectra and (b)TGA curves of pristine h-BN and surface modified h-BN.</p

Lignin-Containing Cellulose Nanofibril-Reinforced Polyvinyl Alcohol Hydrogels

Two lignin-containing cellulose nanofibril (LCNF) samples, produced from two unbleached kraft pulps with very different lignin contents, were used to produce reinforced polyvinyl alcohol (PVA) hydrogels. The effects of LCNF loading (0.25–2 wt %) and lignin content on the rheological and mechanical properties of the reinforced hydrogels were investigated. The 2 wt % LCNF-reinforced PVA hydrogels exhibited up to a 17-fold increase in storage modulus and a 4-fold increase in specific Young’s modulus over that of pure PVA hydrogel. Both the mechanical and rheological properties of LCNF-reinforced PVA hydrogels can be tuned by varying LCNF loading and LCNF lignin content. During LCNF production, lignin reduced cellulose depolymerization, resulting in LCNF with high aspect ratios that promoted entanglement and physical bridging of the hydrogel network. Free lignin particles generated during LCNF production acted as multifunctional nanospacers that increased porosity of the hydrogels. Because LCNFs were produced from unbleached chemical pulps, which have high yields and do not require bleaching, this study provides a more sustainable approach to utilize lignocelluloses to produce biomass-based hydrogels than by methods using commercial bleached pulps

Characteristics of h-BN fillers in different samples.

<p>Characteristics of h-BN fillers in different samples.</p

Enhancement of the heat conduction performance of boron nitride/cellulosic fibre insulating composites - Fig 3

<p>(a) The thermal conductivity of the composites with different BN fillers (b) Schematic diagram of the hydrogen bond between fillers and cellulosic fibres.</p

Thermally Stable Cellulose Nanocrystals toward High-Performance 2D and 3D Nanostructures

Cellulose nanomaterials have attracted much attention in a broad range of fields such as flexible electronics, tissue engineering, and 3D printing for their excellent mechanical strength and intriguing optical properties. Economic, sustainable, and eco-friendly production of cellulose nanomaterials with high thermal stability, however, remains a tremendous challenge. Here versatile cellulose nanocrystals (DM-OA-CNCs) are prepared through fully recyclable oxalic acid (OA) hydrolysis along with disk-milling (DM) pretreatment of bleached kraft eucalyptus pulp. Compared with the commonly used cellulose nanocrystals from sulfuric acid hydrolysis, DM-OA-CNCs show several advantages including large aspect ratio, carboxylated surface, and excellent thermal stability along with high yield. We also successfully demonstrate the fabrication of high-performance films and 3D-printed patterns using DM-OA-CNCs. The high-performance films with high transparency, ultralow haze, and excellent thermal stability have the great potential for applications in flexible electronic devices. The 3D-printed patterns with porous structures can be potentially applied in the field of tissue engineering as scaffolds

Superflexible Wood

Flexible porous membranes have attracted increasing scientific interest due to their wide applications in flexible electronics, energy storage devices, sensors, and bioscaffolds. Here, inspired by nature, we develop a facile and scalable top-down approach for fabricating a superflexible, biocompatible, biodegradable three-dimensional (3D) porous membrane directly from natural wood (coded as flexible wood membrane) via a one-step chemical treatment. The superflexibility is attributed to both physical and chemical changes of the natural wood, particularly formation of the wavy structure formed by simple delignification induced by partial removal of lignin/hemicellulose. The flexible wood membrane, which inherits its unique 3D porous structure with aligned cellulose nanofibers, biodegradability, and biocompatibility from natural wood, combined with the superflexibility imparted by a simple chemical treatment, holds great potential for a range of applications. As an example, we demonstrate the application of the flexible, breathable wood membrane as a 3D bioscaffold for cell growth