Advanced Functional Electromagnetic Shielding Materials:A Review Based on Micro‑Nano Structure Interface Control of Biomass Cell Walls

Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.

The Research Application of 3D Laser Scanning Technology in the Deformation Detection of Large Cylindrical Oil Tank

In order to ensure the safety in using a large cylindrical storage tank,it is necessary to regularly detect its defonnatioii.The traditional total station method has high accuracy in determining the deformation,however,it has a low measxirement efficiency.Long-term observation means,there are more risks in the petrochemical plant,therefore,this paper proposes the usage of the 3D laser scanner,replacing the traditional total station to determine the defbnnation of a large cylindrical storage tank.The Matlab program,is compiled to calculate the point cloud data,while the tank deformation is analyzed from two different points which are,the local concave convex degree and the ovality degree.It is concluded that,the difference between the data obtained by 3D laser scanning,and total station is within the range of oil tank deformation limit,therefore,3D laser scanner can be used for oil tank deformation detection.

Parameter Method Data Processing for CPⅢ Precise Trigonometric Leveling Network

In view of the limitation of the difference method,the adjustment model of CPⅢprecise trigonometric leveling control network based on the parameter method was proposed in the present paper.The experiment results show that this model has a simple algorithm and high data utilization,avoids the negative influences caused by the correlation among the data acquired from the difference method and its accuracy is improved compared with the difference method.In addition,the strict weight of CPⅢprecise trigonometric leveling control network was also discussed in this paper.The results demonstrate that the ranging error of trigonometric leveling can be neglected when the vertical angle is less than 3 degrees.The accuracy of CPⅢprecise trigonometric leveling control network has not changed significantly before and after strict weight.

A Soy Protein-Based Composite Film with a Hierarchical Structure Inspired by Nacre

Soy protein-based composite film is a potential replacement for petroleum-based film with multipurpose applica-tions and cleaner production.It is difficult to improve both the tensile strength and toughness of a protein-based film without sacrificing its elongation.In this study,inspired by the hierarchical structure of nacre,a facile yet delicate strategy was developed to fabricate a novel bio-based film with excellent toughness and high strength.Triglycidylamine(TGA)crosslinked soy protein(SPI)as hard phase and thermoplastic polyurethane elastomer(TPU)as soft phase comprise an alternative lay-up hierarchical structure.The interface of these two phases is enhanced using triglycidylamine(TGA)surface-modified TPU(MTPU).The tensile strength of SPI/MTPU/TGA films increases by 392%to 7.78 MPa and their toughness increases by 391%to 8.50 MJ/m^(3) compared to soy protein/glycerol film.The proposed hierarchical structure can also be extended to other high-performance materials and polymers.

High strength mullite-bond SiC porous ceramics fabricated by digital light processing

Fabricating SiC ceramics via the digital light processing(DLP)technology is of great challenge due to strong light absorption and high refractive index of deep-colored SiC powders,which highly differ from those of resin,and thus significantly affect the curing performance of the photosensitive SiC slurry.In this paper,a thin silicon oxide(SiO_(2))layer was in-situ formed on the surface of SiC powders by pre-oxidation treatment.This method was proven to effectively improve the curing ability of SiC slurry.The SiC photosensitive slurry was fabricated with solid content of 55 vol%and viscosity of 7.77 Pa·s(shear rate of 30 s^(−1)).The curing thickness was 50μm with exposure time of only 5 s.Then,a well-designed sintering additive was added to completely convert low-strength SiO_(2) into mullite reinforcement during sintering.Complexshaped mullite-bond SiC ceramics were successfully fabricated.The flexural strength of SiC ceramics sintered at 1550℃in air reached 97.6 MPa with porosity of 39.2 vol%,as high as those prepared by spark plasma sintering(SPS)techniques.

Research Progress of Soybean Protein Adhesive:A Review

Traditional formaldehyde-based adhesives rely excessively on petrochemical resources,release toxic gases,and pollute the environment.Plant-derived soybean protein adhesives are eco-friendly materials that have the potential to replace the formaldehyde-based adhesives used to fabricate wood-based panels.However,the poor water resistance,high brittleness,and poor mildew resistance of soybean protein adhesives limit their industrial applications.This article reviews recent research progress in the modification of soybean protein adhesives for improving the bonding performance of adhesives used for wood-based panel fabrication.Modification methods were summarized in terms of water resistance,solid content,and mildew resistance.The modification mechanisms and remaining problems were also discussed.Finally,the current industrial applications and the future research direction of soybean protein adhesives are discussed.

Tuning on passive interfacial cooling of covalent organic framework hydrogel for enhancing freshwater and electricity generation

Developing an efficient freshwater and electricity co-generation device(FECGD)can solve the shortage of freshwater and electricity.However,the poor salt resistance and refrigeration properties of the materials for FECGD put big challenges in the efficient and stable operation of these devices.To address these issues,we propose the covalent organic framework(COF)confined co-polymerization strategy to prepare COF-modified acrylamide cationic hydrogels(ACH-COF),where hydrogen bonding interlocking between negatively charged polymer chains and COF pores can form a salt resistant hydrogel for stabilizing tunable passive interfacial cooling(TPIC).The FECPDs based on the TPIC and salt resistance of ACH-COF display a maximum output power density of 2.28 W m-2,which is 4.3 times higher than that of a commercial thermoelec-tric generator under one solar radiation.The production rate of freshwater can reach 2.74 kg m-2 h-1.Our results suggest that the high efficiency and scala-bility of the FECGD can hold the promise of alleviating freshwater and power shortages.

Nucleophilic amino acids as a renewable alternative to petrochemically-derived amines in glycerol epoxy resins

The standard epoxy resin curing agents revealed are from unsustainable petroleum-based sources,which produce poisonous exhaust when cured.Amino acids,a bio-based epoxy curing agent with amino and carboxyl groups,are another potential curing agent.Water-soluble epoxy resins cured with lysine(Lys),glutamic acid(Glu),leucine(Leu),and serine(Ser)as amino acids were inves-tigated.The results showed that the water-soluble epoxy resin(glycerol epoxy resins,GER)was cured with Lys and Glu after reacting.Fourier transform infrared(FT-IR)spectroscopic analysis of the GER-Lys showed that the amino and carboxyl groups of Lys primarily reacted with the epoxy groups of GER.The elongation at break of Lys-cured GER(GER-Lys)cured at 70℃ with a molar ratio of 1꞉0.75 was 75.32%.The fact that elongations at break of GER-Lys(79.43%)were higher than those of GER-Glu(17.33%),respectively supports the decrease of crosslinking density by the amino acid-cured GER reaction.The potential of Lys and Glu alternatives for petrochemical amines is demonstrated and provides promising opportunities for industrial application.

Flexible,durable,and anti-fouling nanocellulose-based membrane functionalized by block copolymer with ultra-high flux and efficiency for oil-in-water emulsions separation

The clearwater obtained from stabilized oily wastewater has become a worldwide challenge.Nowdays,the area of oil/water emulsion separation materials have accomplished great progress,but still faces the enormous problems of low flux,poor stability,and pollution resistance.Nanocelluloses(cellulose nanocrystals(CNC))with the advantages of hydrophilicity,ecofriendliness,and regeneration are ideal materials for the construction of separation membranes.In this paper,a flexible,antifouling,and durable nanocellulose-based membrane functionalized by block copolymer(poly(N-isopropylacrylamide)-b-poly(N,Ndimethylaminoethyl methacrylate))is prepared via chemical modification and self-assembly,showing high separation efficiency(above 99.6%)for stabilized oil-in-water emulsions,excellent anti-fouling and cycling stability,high-temperature resistance,and acid and alkali resistance.More importantly,the composite membrane has ultra-high flux in separating oil-in-water emulsions(29,003 L·m^(−2)·h^(−1)·bar^(−1))and oil/water mixture(51,444 L·m^(−2)·h^(−1)·bar^(−1)),which ensures high separation efficiency.With its durability,easy scale-up,and green regeneration,we envision this biomass-derived membrane will be an alternative to the existing commercial filter membrane in environmental remediation.

Thermo-controlled,self-released smart wood tailored by nanotechnology for fast clean-up of highly viscous liquids

Designing highly porous materials is of great importance for liquid separation,water purification,and disinfection,such as spill oil cleaning and recycling,seawater desalting,and oil/water separation.However,a remaining challenge is to produce porous materials with the characteristics of fast absorption,continuous directional transport,and self-release of viscous liquid.Herein,a functional cellulosic composite is reported by the chemical treatment and functionalization of wood resulting in a smart wood that can thermally selfrelease and separate high viscosity oil.The smart wood has a high absorption speed of 1398 mL/(m_(2)·s)(ethylene glycol)and a maximum absorption capacity of 47.2 g/g(chloroform)due to its intrinsic vertical micro/nanoscale channel structure,low tortuosity,and high porosity.Moreover,the switchable wettability is achieved by the surface coating of poly(N-isopropylacrylamide)on the porous wood,which enables the collection and removal of oil from the oil/water mixture.The high viscosity oil can be automatically released due to the passive oil release at room temperature.The release capacity of the smart wood remains above 91%after 15 cyclic tests.We envision that this functional smart wood could be extended to a wide range of applications in smart hydrogels,microfluidics,artificial drug release,and environmental restoration.

A bifunctional wood membrane modified by MoS_(2)/covalent organic framework heterojunctions for effective solar-driven water evaporation and contaminant degradation

Interfacial solar evaporation technology is considered one of the most promising strategies for alleviating the scarcity of freshwater resources.However,solar-driven evaporation technology cannot eliminate the pollutants in the residual wastewater.To solve this problem,we have prepared a two-in-one solar-driven evaporation/photocatalysis system by decorating MoS_(2)/covalent organic framework(COF)heterojunctions on wood(MoS_(2)/COF-wood).Thanks to the unique porous structure of wood,it provides a strong guarantee for water transport and vapor release during the evaporation process.The introduction of MoS_(2) and COFs can promote the breaking of hydrogen bonds between water molecules,which leads to a significant decrease in the enthalpy of evaporation,achieving a water evaporation rate as high as 2.17 kg m^(-2)h^(-1)under 1 sun irradiation.Meanwhile,the resulting MoS_(2)/COF-wood exhibits good salt resistance and reusability.In addition,the heterojunctions formed between COFs and MoS_(2) can effectively inhibit charge carrier complexation and improve the photocatalytic degradation ability of pollutants(over 99%).This study highlights the construction strategy of bifunctional wood-based materials for freshwater production and wastewater remediation.

In-Situ Chemosynthesis of ZnO Nanoparticles to Endow Wood with Antibacterial and UV-Resistance Properties

Hybrid wood materials have attracted considerable attention because they have combined advantages of both wood and inorganic compounds. This work investigated the microstructural morphology, thermal stability, ultraviolet（UV） stability, and antibacterial property of composites made from wood/ZnO hybrid materials through a facile in-situ chemosynthesis methods. The X-ray diffraction（XRD） and thermogravimetric analysis（TGA） results indicated that the synthesized ZnO particles had an average grain size of about 10.8 nm. The scanning electron microscopy（SEM） observations showed that ZnO nanoflowers self-assembled with nanosheets were presented in wood cell lumens and increased with increasing Zn^（2＋）concentrations. ZnO nanoparticles were also generated in the wood cell wall, which was confirmed by the results of energy-dispersive spectroscopy（EDS）. The TGA tests also indicated that the thermal stability of wood/ZnO hybrid materials was improved after the formation of ZnO inorganic particles. Finally, the results of antibacterial efficacy tests and UV resistance tests revealed that ZnO nanoparticles showed a promising future as antimicrobial agents against Escherichia coli（E.coli） and UV resistance agents for wood protection.