Due to its flammability, bamboo is gradually becoming incapable of meeting the increasing demand for building decoration materials. In this work, we utilized in-situ synthesis to prepare aluminophosphate (AP) modified bamboo bundles and bamboo scrimber (BS) with high flame retardance and smoke-suppression performance. Benefiting from the in-situ synthesis method, the high yield of hierarchical vertical lamellar AP forms a flowerlike nanostructure and contributes to an organic-inorganic components in bamboo by binding metal ions and phosphate radical to carbohydrates, leading to an effective improvement in flame retardant properties. Under the optimized hydrothermal process, aluminophosphate bamboo scrimber (APBS) had a higher limiting oxygen index (LOI) (41.5 +/- 0.5 %). The Cone calorimeter tests indicated that the APBS had reduced peak heat release rate (pHRR), total heat release (THR), peak smoke production rate (pSPR), total smoke release (TSR), CO production, and CO2 production than the control sample. During the combustion process, AP forms a dense and stable flame-retardant layer on the surface of bamboo, effectively preventing the fibers from coming into contact with oxygen and reducing the release of volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Meanwhile, the Lewis acidity of AP can catalyze the dehydration and carbonization of cellulose in bamboo at lower temperatures, leading to the formation of a continuous and stable carbon layer. This study presents a sustainable, simple, and environmentally friendly approach to prepare AP materials that serve as effective flame retardants and smoke suppressants, thereby eliminating fire hazards associated with bamboo or other cellulosic materials.

Renewable and biodegradable plant fiber sponges (PFS) can be used as substitutes for some petroleum-based polymers. They could make a positive contribution to the daily carbon footprint. However, the natural fire hazard of PFS could result in a severe safety concern and restrict their application. Herein, a highly thermo-conductive hexagonal boron nitride (h-BN) ink with anisotmpic thermal conductivity was developed as a fire retardant to modify the PFS (defined as PFS@h-BN) through a simple but effective dip-coating strategy. The additive h-BN nanosheets can be homogeneously deposited on plant fibers' surfaces to form a good protective barrier, improving their fire resistance at high temperatures. Compared to the PFS, a 29.0% enhancement in limiting oxygen index value, fourfold prolongation in time to ignition, 500s enhancement in time to flameout, 21.0% reduction in the peak heat release rate, 35.1% decrease in the total smoke release, and 1.47 MPa enhancement in compression strength (epsilon = 80%) of PFS@h-BN were achieved. The obtained PFS@h-BN meet the requirements of environmentally friendly, scalable production, good fire safety, and mechanical performances, indicating a promising structural material for safe and energy-efficient building application.

Unsaturated polyester resin (UPR) with good chemical resistance, excellent mechanical properties, and formaldehyde-free shows great potentials in the wood industry. In this study, the mechanical strength, thermostability, dynamic thermomechanical property, and interfacial bonding of bamboo particle boards (BPBs) made from UPR adhesives with toluene diisocyanate (TDI) as the coupling agent were explored. The results showed that covalent bonds were formed among TDI, bamboo particles, and UPR, which could significantly enhance the mechanical strength. The internal bonding strength, modulus of elasticity, and modulus of rupture of treated BPBs were 1.36, 3010, and 19.6 MPa with the increment of 1250, 514, and 833%, respectively, compared to the control samples. Also, the thickness swelling rate of the BPB was 4.6%, much lower than that of the control, with a decrease of 92%. The thermostability of the treated BPB was also improved. As a result, the BPB using UPR as the adhesive and TDI as the coupling agent shows better usability, higher efficiency, and excellent mechanical strength.

Wood adhesives are mostly synthesized from unsustainable and hazardous petrochemical-based formaldehyde. Recently, an inorganic, sustainable and environmentally friendly aluminophosphate adhesive was developed for fabricating various wood-based panels. In order to increase its competitiveness, this study developed an approach for improving the interfacial adhesion of aluminophosphate. Hence, carboxymethyl cellulose was functionalized using 3-aminopropyl triethoxysilane to alter the chemical structures of the adhesive. Thereafter, a face-centered central composite design based on response surface methodology was employed to generate the optimum production conditions for the improved plywood interfaces. Adhesive concentration and hot-press temperature were seen as the significant factors within tested limits. The most appropriate production variables were suggested with a valid predictive model for such conditions. Also, the reaction mechanisms revealed the successful altering of the aluminophosphate properties with a well-uniform adhesive surface. The results indicate that modified adhesives are more thermally stable. Furthermore, the wet bonding strength of the modified adhesive was improved above the minimum threshold (Chinese type II standard >= 0.70 MPa). Therefore, the sustainable (i.e. continuous availability of CMC) approach adopted in this research could be considered as a viable method for improving the properties of aluminophosphate adhesives.

An aluminophosphate adhesive was used as the binder in plywood. The hot-pressing parameters of aluminophosphate adhesive-based plywood (APPs) including hot-press temperature (A), time (B), and pressure (C) were optimized using response surface methodology. Results indicated that the hot-press temperature was the most dominant factor. The maximum bonding strength of 1.98 MPa was found with an optimal parameter of 171 °C (hot-press temperature), 7.5 min (hot-press time), and 1.0 MPa (hot-press pressure). Additionally, the chemical reaction mechanism between aluminophosphate adhesive and wood fibers was characterized by X-ray photoelectron spectroscopy (XPS). Results showed that good interaction was generated between wood fibers and adhesives through their surface functional groups. In conclusion, the optimized pressing conditions of plywood significantly improved bonding strength of APPs.

Increasing environmental problems caused by the emission of crude oil, petroleum products, and toxic organic solvents have threatened ecosystems and human health. Renewable and eco-friendly natural materials are considered as the most promising absorbents for removing oils and organic solvents from water. In this work, a hydrophobic plant fiber sponge (PFS) is successfully prepared via a simple vapor treatment strategy with hexamethyldisilazane (HMDS) (defined as PFS@HMDS). The as-prepared PFS@HMDS with high porosity, high mechanical durability, and excellent hydrophobicity with a water contact angle of 145 degrees exhibits high oil absorptive capacity (15-40 g/g) and selectivity. It also shows the excellent structural stability, durability, and high reusability in the repeated absorption/desorption cyclic testing. More importantly, it can achieve continuous oil/water separation with the assistance of a miniature diaphragm pump. Owing to these favorable advantages, the PFS@HMDS demonstrates its potential application in oil/water separation and organic solvents removal.

Aluminum phosphate (AP) shows great potential to replace formaldehyde-based adhesives in the wood industry, except for its weak hygroscopic resistance and low wet bonding strength. This study chose PVA as an AP modifier to prepare a PVA-AP organic-inorganic hybrid adhesive (PAP). The preparation, bonding mechanism and heat resistant property of PAP were studied by using X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). The result showed that covalent bonds between PVA and AP were built. The mechanical properties of PAP improved remarkably; the dry and wet bonding strength are 2.28 and 0.79 MPa with 15.2% and 690% increment, respectively, compared to the control samples. The thermostabilities of PAP and plywood samples were improved. In conclusion, PVA could effectively improve the hygroscopic resistance and low wet bonding strength of AP adhesives.

Nutrient-rich raw bamboo materials can be infected by mildew when exposed to water or high humid environments. This not only affects the appearance of bamboo products, but it also contributes to respiratory diseases. Herein, four anti-mildew agents, i.e., boric acid, copper sulphate, alumina phosphate sol, and alumina silicate sol, were used to evaluate their anti-mildew performances. The results showed that the adequate anti-mold concentrations of boron and copper were 2% and 0.7%, respectively. The optimum mass ratio of aluminum phosphate sol and silicone aluminum sol were 1 to 1 (2% phosphoric acid addition) and 10 to 1 (aluminum salt addition was 1.5%). There were significant differences in the prevention and treatment effects of different mold inhibitors on mold and discoloration bacteria. The efficacies order of the anti-mildew property was as follows: copper sulphate > alumina silicate sol > boric acid > alumina phosphate sol. In addition, the order for stain fungi resistance was: boric acid > alumina phosphate sol > alumina silicate sol > copper sulphate. The selected anti-mildew agents showed promising application requirements as an active ingredient in bamboo preservative systems.

在单因素试验的基础上,采用响应面分析软件分析了聚乙烯吡咯烷酮添加量、热压时间、热压温度3个因素对胶合板胶合强度的影响.结果表明:在聚乙烯吡咯烷酮添加量10.00％、热压温度163.00℃、热压时间3.70 min的条件下,胶合板的胶合强度可达1.33 MPa,与预测值相差较小.流变性能分析表明:聚乙烯吡咯烷酮的加入使得磷铝胶粘剂的粘度增大,改性胶粘剂的粘度与聚乙烯吡咯烷酮添加量呈正相关红外分析结果表明聚乙烯吡咯烷酮可与磷酸二氢铝之间形成氢键,胶粘剂改性前后与单板之间的粘接力主要由氢键提供.

Fire safety issues have attracted much attention since they cause enormous loss of lives and properties. In this study, the sustainable aluminophosphate (AP) adhesive is developed as a fire retardant for improving the fire performance of medium-density fiberboard (MDF). The properties of AP adhesive and AP-based MDF were evaluated based on a scanning electron microscope, thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and cone calorimetry. The thermostability and fire performance of MDF are significantly improved by the deposition of the AP inorganic layer on the wood fibers surface, which could protect wood fibers from further oxidation and take away part of the heat. Compared to control sample (UF sample), the pkHRR (151.7 kW mz), THR (66.0 MJ mz), TTI (21 s), and mean EHC (14.6 MJ kg(-1)) of AP-based MDF was reduced by 52.7%, 39.0%, 41.7%, and 32.8%, respectively. Also, the existence of the AP inorganic layer is beneficial to netting the solid phase and volatile flammable components in char residue of MDF, resulting in large mass loss rate, off-gases (CO and CO2) release and smoke suppression properties. Therefore, AP could improve the fire performance of MDF. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Due to the hydrophilic nature of the aluminophosphate (AP) adhesives, their application in the wood-based board (WBB) industries is rarely considered. Herein, the AP adhesives with reduced graphene oxide (AP@rGO) were developed for the construction of hydrophobic surface, mainly for the improvement of the water resistance of AP-based WBB interface as well as their mechanical properties and fire resistance. Results indicated that there is an excellent interfacial adhesion between the AP@rGO and fibers, making the APW@rGO achieved a high dry bonding strength of 2.77 MPa. Utilizing the advantages of rGO network with outstanding water resistance, the WBB engineered the comparable wet bonding strength as high as 1.65 MPa, meeting the minimum requirement of the plywood standard stated in GB/T9846.3-2004. Also, AP@rGO exhibited an excellent fire resistance properties and smoke suppression ability. Benefiting from these remarkable results, the AP@rGO could be broadly developed for practical applications in related wood-based products.

Fungi play a considerable role in the deterioration of lignocellulose materials, as their activities either affect the esthetic properties or lead to decay of the host materials. The new generation of organic-inorganic preservatives, which are copper-based but chrome- and arsenic-free, is a subject of many research works. Mildew fungus prevention, treatment of affected materials, and their successive conservation are essential to the woodworkers. To prevent degradation and prolong the service life of wood, a sol-gel organic-inorganic procedure was employed in this study. Aluminum sulfate (Al2(SO4)3), copper sulfate (CuSO4·5H2O), and boric acid (H3BO3) were introduced into phosphoric acid (H3PO4) and water glass as an antimildew agent, with different treatment concentrations (0.7, 1.4, and 2%). Wood was inoculated with Aspergillus niger and Trichoderma viride after new treatment based on the inorganic preservative. The changes in wood surface, structural chemistry, and the crystalline structure of the treated wood were examined by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD), respectively. The growth of the two mildew fungi showed distribution, and evidence of mildew covering only the untreated wood surfaces and an increase in the crystallinity of wood was observed after the process. The study suggests that the two mildew fungi investigated herein could be prevented by sol-gel coating with a Si-Al-Cu-P antimildew agent.

With increasing demand for wearable electronics, highly sensitive and flexible piezoresistive sensors (PRS) have received increasing attention. As an important component, structural materials with high compressibility and electrical conductivity are a powerful impetus for the development of PRS. Since the structural deformation occurred during high-temperature carbonization makes many three-dimensional porous structures made from low-cost biomass unsuitable for fabricating flexible PRS, we propose a convenient carbonization-free route to prepare PRS devices based on natural plant fibers. By developing and using a water-based conductive ink, the surface modification and assembly of plant fibers can be integrated into a one-pot foaming process to generate ink-modified plant fiber sponges (m-PFS). Benefiting from favorable mechanical property and sensitivity (133.3 kPa(-1) in a pressure range of 10 similar to 750 Pa), the polydimethylsiloxane packaged m-PFS is demonstrated as a high-performance flexible PRS for detecting human physiological signals. This study provides new opportu-nities for the application of biomass in wearable electronics and human health monitoring.

To reduce the use of formaldehyde wood adhesives, a chemical modification of starch with chitosan was explored to prepare an adhesive film for plywood with good adhesive properties, low price, non-toxic, and convenient sizing. The effect of chitosan content of the adhesive film on the shear strength of plywood was studied. The modification mechanism and bonding mechanism of the film were analyzed by FTIR, XPS, XRD and SEM. The results showed that when the amount of chitosan was 30% of starch dry weight, the dry-wet shear strength of plywood met the requirements of Chinese national class II plywood (>= 0.80 MPa). FTIR and XPS analysis showed that -NH2 in the chitosan reacted with -COOH on starch and wood surface to form amide bond, which specifies the chitosan's role as a coupling agent. XRD and SEM analysis showed that the addition of chitosan disturbed the otherwise orderly arrangement of a starch structure. The structure of the attained modified film is mostly amorphous. Sizing in the form of a adhesive film solves the disadvantage of difficulty in sizing starch adhesive. Compared with commercial adhesives on the market, this adhesive film has the advantages of low price, wide source of raw materials, non-toxic, and is expected to be a good substitute for formaldehyde adhesives on the market. (C) 2020 Published by Elsevier Ltd.

In recent years, considerable attention have been given to the development and utilization of biodegradable fibres for bio-composite boards. This is due to the increase in the environmental consciousness and the need for sustainable development which enable establishment of new materials majorly for packaging, aircraft, furniture, and automobile. Straw fibres (wheat, rice, and corn fibre) are the most available natural agricultural wastes products, which has been utilized for the production of these new materials. This paper hence reviews the enhancement in production methodology and properties of the straw fibres bio-composite boards to add further scientific knowledge to the potentiality of using agricultural fibres as value added products. The future replacement of conventional wood fibres for the production of bio-composite panels, especially with agricultural wastes, could be centered on straw fibres. The introduction of straw fibres in polymer matrices were presented based on various research outcomes. Biodegradable fibres could be regarded as a good fibrous composite material. Although, more efforts are still needed in developing facile straw fibre composite production methods and materials with robust industrial and domestic applications. Industrial adoption of these fibres would gear effort towards achieving a clean, and pollution free environment.

This study describes the application of aluminum sulfate Al2(SO4)3, boric acid H3BO3, phosphoric acid H3PO4 (Al–B–P) and amphiprotic surfactant material synthesis by the sol-gel process, which were adopted as novel precursors for wood modification. The efficacy of Al–B–P-treated wood was tested against Poria placenta and Coriolus versicolor. Untreated wood samples had higher mass losses (>40%) compared to the treated sample, which had the lowest wood mass losses (of 4%) against P. placenta and C. versicolor. To analyze the reaction mechanism of Al–B–P wood, the mechanical properties, chemical structure, crystallinity, thermal analysis, binding energy and wettability was examined by modulus of rupture (MOR), modulus of elasticity (MOE), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), Thermogravimetric analysis (TG) and X-ray photoelectron spectroscopy (XPS), respectively. Scanning electron microscopy- energy-dispersive X-ray spectroscopy (SEM-EDS) confirmed the wood colonization by fungi, and was used to identify the microstructures and morphologies changes that occurred in the cells during degradation by white and brown-rot fungi. At the same time, X-ray photoelectron spectroscopy (XPS) was employed to analyze the physical and chemical properties of the samples. Therefore, the study confirmed that Al–B–P and amphiprotic surfactant could replace the traditional wood preservative products, and have the potential to extend the service life of wood, particularly in soil contact and outdoor usage.

Solar steam generation as a promising solar energy conversion technology has attracted considerable interest in achieving seawater desalination and water purification. Although wood with fast water transportation and excellent heat localization has drawn particular interest in regard to its application for solar steam generation, challenges still remain in terms of its complicated processing techniques and relatively low efficiency. Here, we propose a facile, cost-efficient, and scalable brushing method to prepare an aluminophosphate-treated wood (Wood@AlP) solar steam generation device. The aluminophosphate compound deposited on the wood surface can not only be considered as the Lewis acid catalyst capable of accelerating the formation of the carbon layer but also provide an aluminophosphate layer with a hierarchical porous structure, which is beneficial for broad solar absorption and vapor escape. On the other hand, benefiting from the natural hydrophilicity, low thermal conductivity, and excellent water transportation of wood, the obtained Wood@AlP device can float on seawater and exhibit a high solar thermal efficiency of 90.8% with a net evaporation rate of 1.423 kg m-2 h-1 under 1 sun illumination.

为考察硅铝无机防腐处理对竹材表面颜色的影响,以毛竹为材料,采用不同热处理溶液浓度(0、25％、50％、100％)、 处理温度(140、160、180℃)和处理时间(1、2 h)分别对其进行处理.依照标准色度系统指定表征防腐处理前后竹材表面颜色,通过颜色总色差、 明度、 红绿色指数、 蓝黄色指数的变化,探讨防腐处理工艺参数对竹材表面颜色的影响.通过傅里叶红外光谱和X衍射光谱分析防腐液与竹材结合方式,并使用场发射扫描电子显微镜观察对比处理前后防腐液在竹细胞腔内的分布情况.结果表明,防腐液浓度对竹材色差变化影响较大,随着浓度的增大,竹材色差也随之增大.热处理工艺的处理温度与处理时间对竹材表面颜色的影响也符合传统木材热处理色差变化规律.微观检测发现,防腐剂不仅与纤维有化学键结合,也通过物理吸附以分子团聚形式附着填充在细胞腔内部.

The application of aluminophosphate adhesives in wood-based panel industries is limited by the adhesives' inherent disadvantage of poor water resistance caused by their mesoporous nature. In this study, poly(vinyl alcohol) was used as the modifier while glutaraldehye was employed as the cross-linker to reduce the water-uptake of the aluminophosphate bond interface in Pinus massoniana plywood. The influence of the cross-linking on the reaction mechanism, morphology, thermal stability of the adhesives, and tensile strength of the plywood was examined using FTIR, XRD, XPS, TGA, and SEM analyses. The SEM images showed the absence of pores on the adhesive surface at 1, 3, and 5% glutaraldehyde. Crystalline peaks were observed in aluminophosphate adhesives at a lower reaction temperature (110 degrees C). The C-O bonds were reduced, leading to the increase in C-C/C-H that could account for the bond stability in water after revealing hydrogen bonding between the plywood interfaces. Consequently, the wet tensile strength of PVA/aluminophosphate-based plywood was enhanced significantly (P < 0.05) above the type II Chinese standard, achieving a strength as high as 1.02 MPa. Also, the dry tensile strength improved slightly to 2.34 MPa compared to unmodified aluminophosphate adhesive. Therefore, modification with PVA and the addition of glutaraldehyde as a cross-linker could enhance the water stability of aluminophosphate-based plywood. This research has demonstrated the potential improvement of the plywood bondline and the industrial utilization of formaldehyde-free aluminophosphate adhesive for the wood-based panels.

利用生长于我国的圆竹为材料,通过竹材阻燃、防霉和固色处理工艺,可形成高强、环保、美观的低碳绿色会展材料.通过设计连接点的金属节点设计和圆竹的结构设计,可实现圆竹在展台、展柜和展架支撑构件中的应用.