To endow wood plate with antimicrobial properties, waterborne polyurethane (WPU) coatings incorporated with nano cellulose crystalline (NCC) and silver nanoparticles (AgNPs) were prepared. AgNPs were obtained by the chemical reactions of silver nitrate solution and sodium borohydride solution. The scribe testing results showed that the adhesion of the NCC-WPU composites was improved with the addition of NCC. The adhesion reached its peak when the amount of NCC added was 1%. Scanning electron microscopy (SEM) observation displayed that the NCC dispersed into the WPU without aggregation. NCC was well able to bind WPU and wood cell walls tightly together. Atomic force microscopy (AFM) and ultraviolet-visible (UV-vis) results revealed that WPU/NCC/AgNPs composites were homogeneous. This compatibility was also confirmed by transmission electron microscopy (TEM) analysis. The antibacterial property was improved too. When the adding amount of NCC was 0.5%, and the proportion of silver elements added was 5%, the antibacterial effect was at its best. As a comparison, the antibacterial effect of hybrid colloid without the addition of NCC was far less than that of including NCC. The WPU/NCC/AgNPs composite could be applied as an antibacterial coating in wood materials.

In the interiors of ancient Huizhou buildings in China, a profusion of wood carvings are employed for decoration, with traditional research interpreting their function from decorative and aesthetic perspectives. However, this research suggests that the role of Huizhou wood carvings in interior spaces surpasses mere decoration; they enhance the expression and experience of spatial concepts through narrative imagery. By analyzing the mechanism and intrinsic logic behind the spatial concepts formed in Huizhou residential buildings, this study investigates how wood-carving imagery contributes to shaping spatial concepts through narrative techniques, as well as their creativity and expressiveness in architectural design. Utilizing literature reviews, field surveys for case selection, and case analysis methods combined with observation, interviews, and measurements, this research ultimately employs image analysis to interpret the narrative structures and styles of wood-carving imagery in detail. This study reveals that (1) the spatial concepts of Huizhou residential buildings are influenced by traditional thought, social culture, and other factors, leading to an interweaving of material, cultural, and social spaces that results in a spatial concept characterized by harmony between heaven and humanity, clear hierarchy, and orderliness; (2) Huizhou wood-carvings, through their narrative images, actively engage in the production of spatial concepts, employing thematic juxtaposition narrative modes and utilizing singular-scene narration, composite-scene narration, and cyclical narration to articulate these concepts. These findings significantly deepen our comprehension of the relationship between the spatial concepts of Huizhou’s traditional residential architecture and social culture. By integrating cultural elements with spatial production theory, this research addresses the limitations of existing studies and augments their theoretical interpretative power. Additionally, clarifying the connection between the cultural elements of wood-carving imagery and the formation of spatial concepts offers a novel perspective on the study of Huizhou wood carvings, moving beyond their longstanding categorization as purely decorative elements.

Waterborne polyurethane (WPU) has emerged as one of the most promising environmentally friendly coating materials owing to its low volatile organic compound (VOC) emissions, excellent film-forming ability, good adhesion, and versatility in formulation. However, WPU suffers from several intrinsic limitations including inadequate thermal stability, modest mechanical strength, poor flame retardancy, and a lack of inherent antibacterial activity. To address these deficiencies, phosphorylated microfibrillated cellulose (PMFC), prepared from beech wood sawdust via sequential steam explosion, phosphorylation, and superfine grinding, was employed as a substrate for in situ silver nanoparticle (AgNPs) synthesis and subsequent incorporation into WPU via aqueous blending and solvent casting. PMFC functions through a combined mechanism: the hydroxyl and phosphate groups coordinate Ag⁺ ions, providing nucleation sites, while the nanofibrillar network provides steric stabilization against post-synthesis aggregation. The influence of AgNPs loading (1–10 wt% relative to PMFC at a fixed 1 wt% PMFC content) on the morphology, antibacterial activity, silver release behavior, thermal stability, flame retardancy, and mechanical properties of the resulting composite films was comprehensively investigated using free-standing composite films as a model system. At the optimal Ag loading of 5 wt%, the composite exhibited strong antibacterial activity against Escherichia coli with silver release below 1.15 ppb after 96 h, while tensile strength and Young’s modulus increased by 80% and 298%, respectively, relative to neat WPU. At high Ag loadings (70–80 wt%), the composites achieved conductive-level surface resistivity (~3 log Ω) through percolation network formation, demonstrating antistatic functionality. This study provides an effective strategy for fabricating WPU composite films with combined antibacterial, mechanical reinforcement, and antistatic capabilities.

Lignin-containing micro/nano fibrillated cellulose (L-MNFCs) and phosphorylated L-MNFCs were produced from beechwood sawdust by combining steam explosion (SE) pretreatment, a bleaching step, a phosphorylation reaction using urea and etidronic acid, and an ultra-fine grinding. The contents of phosphorus and nitrogen on the cellulose surface were obtained by elemental analysis (P ≈ 2.7% and N ≈ 1.2% respectively). The chemical composition of the pulps was assessed by ionic chromatography (HPAEC PAD) and the morphology of phosphorylated (L-)NMFCs were analyzed by Morfi Neo. The successful grafting of phosphate groups was verified by FTIR, ¹³C CPMAS, ³¹P NMR. Thermal and fire behaviors were examined by TG/DTG analysis and pyrolysis combustion flow calorimetry (PCFC). It was found that SE pretreatment itself can significantly improve the thermal degradability and fire resistance of L-MNFCs. Phosphorylated (lignocellulosic) micro/nano fibrillated cellulose exhibiting a remarkable elevation in their thermal degradation and flame-retardancy have been produced.