In recent decades, electromagnetic shielding materials have been widely explored due to their promising applications in electronic communication, aerospace, military, and medical equipment. Numerous pioneering works have been reported on MXene/nanocellulose composites, which possess various structures and excellent electromagnetic shielding properties. This article reviews the latest progress of MXene/nanocellulose composites in electromagnetic interface shielding applications, with a particular focus on preparation strategies, toughening mechanisms, and structural design. More importantly, we have reviewed the toughening mechanism of MXene/nanocellulose composites from three aspects: physical toughening mechanism, chemical toughening mechanism, and synergistic toughening mechanism. In addition, we systematically analyzed the current technological limitations and proposed potential research directions to guide future development. This work will greatly advance the rational design and practical application of high-performance MXene/nanocellulose electromagnetic shielding composites.

With the rapid development of terahertz (THz) technology in ultra-high-speed communication and security inspection applications, there is a growing demand for high-performance THz shielding and absorbing materials to prevent electromagnetic interference (EMI) or pollution. Natural hierarchical staggered cellular structures, such as bones and wood, feature abundant micropores/channels and interlocking staggered layered architectures. The architectural feature promotes multi-reflection and absorption of electromagnetic waves, prolonging their propagation path and strengthening wave attenuation. Inspired by this, a bioinspired strategy was proposed to fabricate multilayer-MXene (m-Ti₃C₂T_x)/cellulose nanofibrils (CNFs) aerogel frameworks with staggered stacking architectures via direct ink writing (DIW) three-dimensional (3D) printing technology for enhanced THz shielding and absorption performance. Through comprehensive optimization, we achieved composite inks with outstanding rheological properties and identified optimal printing parameters, enabling high-precision and stable 3D printing fabrication. The framework exhibits an excellent maximum reflection loss (RL) of 54.01 dB in the 0.5–3.0 THz range (100% qualified bandwidth) and a high absorption of 99.40%. It realizes a high green shielding index (g_s), the range of g_s > 9 that meets the standard for excellent green EMI shielding up to 2.5 THz. Meanwhile, it demonstrates high shielding effectiveness (SE) exceeding 40 dB across a broad gigahertz (GHz) frequency range from 3.9 to 18 GHz, particularly reaching an excellent 101.84 dB in the Ku band. This work provides a simple and efficient way to achieve outstanding THz shielding and absorption performance.

In addition to cellulose and lignin, hemicellulose is an important biomass material. Recently, hemicellulose and its derivatives and materials have attracted increasing attention owing to their unique structures, improved properties, and promising application potential, and many reports on the extraction, isolation, and modification of hemicellulose are currently available. We summarized the recent developments of hemicellulose and its derivatives and materials by focusing on the extraction, purification, and modification of hemicellulose. The synthesis of hemicellulose-based derivatives and materials was also reviewed. Various methods of extracting, isolating, and modifying hemicellulose were discussed. Remaining challenges related to hemicellulose extraction, purification, and application were mentioned, and directions for further research on hemicellulose were proposed.

Nanocellulose composites combine the advantages of nanocellulose and composites. Recently, nanocellulose composites have been received more attentions due to their improved properties and promising broad applications. In the past, rapid progress has been made in the synthesis, properties, and mechanism of nanocellulose composites and potential applications were reported. There are a few reports on the increasing applications of nanocellulose composites with focus on the biomedical field, environmental field, electrode and sensor applications. In this article, the recent development of nanocellulose composites was reviewed via some typical examples. In addition to the synthesis methods, improved properties and potential applications were discussed. The problems and future applications of nanocellulose composites were also suggested.

The aim of this study was to investigate the hemicelluloses extracted from Populus tomentosa Carr. by the hydrothermal method with ethanol. The influence of ethanol concentration on the hemicellulosic fractions was systematically studied. The chemical compositions and structural features of the hemicellulosic fractions were investigated by a combination of sugar analysis, gel-permeation chromatography, Fourier transform infrared spectroscopy, and one-dimensional proton and carbon-13 nuclear magnetic resonance, and two-dimensional heteronuclear single quantum coherence spectroscopy. Neutral sugar analysis of the hemicellulosic fractions revealed that a higher ethanol concentration (45%~80%) favored the isolation of hemicelluloses with more side chains and lower glucose contents. The molecular weights of these polysaccharides ranged between 2842 g/mol and 5101 g/mol. The results of this study indicate that the hydrothermal ethanol process provides a new pretreatment strategy for the isolation and extraction of biomass.

The purpose of this study was to explore the differences of the hemicelluloses extracted by hydrothermal pretreatment using water and alkaline solutions(Na OH or KOH). The physicochemical properties and structural characteristics of two water-soluble and four alkali-soluble hemicelluloses extracted from the triploid of Populus tomentosa Carr. through the hydrothermal pretreatment were comparatively studied. It was observed that the alkalis(Na OH and KOH) were more effective than distilled water as extractants. Sugar analysis showed that xylose(66.83%~86.49%) was the major constituent, followed by glucose(6.83%~18.49%). Mannose(1.40%~8.42%), galactose(2.17%~4.05%), and arabinose(0.21%~2.26%) were also detected in the hemicellulosic fractions. The results of gelpermeation chromatography(GPC) indicated that the hemicelluloses extracted using the alkaline solutions had relatively higher molecular weights than those solubilized in distilled water. Further, based on spectroscopic ¹Hnuclear magnetic resonance(¹H-NMR) and two-dimensional heteronuclear singular quantum correlation(2D-HSQC) analyses, it was confirmed that the hemicellulosic fractions had a major structure of(1→4)-β-D-xylan and a minor structure of(1→4)-α-D-glucan with small amounts of substituted sugars and glucuronic acid attached.