Preparation And Performance Study Of Wood-based Radiation Thermal Managing Materials

Starting from the radiation characteristics of wood fibers themselves,this study developed wood-based radiation heating materials,wood-based dual-mode passive radiation thermal management materials,and ion-dyed passive radiation thermal management materials,and conducted performance research to expand their practical applications in advanced green buildings.The high-strength thermal management material has been developed by making full use of the thermal radiation properties of the wood fibers themselves,and by chemically treating the wood fibers and assembling them in multiple layers using a gel-assisted method to improve their toughness and strength.The specific details are as follows:（1）The wood fibers were pretreated,and a wood-based SAL/α-Cu V₂O₆structural material was prepared using a gel-assisted method and hot-pressing method.The UV absorption characteristics of lignin provided the material’s own photothermal conversion ability,while the addition ofα-Cu V₂O₆nanowires further reduced the emissivity of the composite material and gave it good insulation properties.In the outdoor simulation test,the temperature difference between the bottom of the sample and the environment reached 34.96℃.In terms of mechanics,its bending strength and impact toughness are up to 99 MPa and 69.85 k J m^-2,respectively,which were better than common polymers（such as ABS,PP,and PVC）,natural materials（such as pure wood fiber boards）,and ceramics（such as silicon nitride ceramics）.（2）The wood-based dual-mode passive radiation thermal management material integrates the concepts of radiation cooling and radiation heating.It uses lignin-free cellulose as the cooling side and sodium alginate with added lignin sulfonate as the heating side.The material is made by preparing cellulose and lignin water gel and layer-by-layer hot pressing.The experimental results of the wood-based dual-mode passive radiation thermal management material show that its mechanical strength can reach 102 MPa,which is 4.8 times higher than that of natural wood.The material also has ultra-high specific strength(76.86 MPa g^-1cm³)and specific impact toughness(53.96 k J m^-2g^-1cm³),which are better than many common concretes and polymers.In terms of radiation temperature control,the sample has excellent indoor heating performance and 24-hour cooling performance.This opens up new possibilities for wood-based temperature control materials and promotes research on energy-saving buildings.（3）Colored cooling wood was prepared using ion-stained cellulose fibers by gel-assisted and hot-press methods.The average ion concentration in the sample was found to be 43%.The mechanical strength of the material was measured to be 111 MPa,and the impact toughness was 79.8 k J m^-2.The material not only exhibited rich colors but also showed good radiative cooling performance.Compared to traditional structural materials such as concrete,the three different colored cooling woods decreased the temperature rise by an average of 3.5℃,4.5℃,and 5.1℃under strong solar radiation during the day.The production process was simple,cost-effective,and suitable for industrialization.These results provide a practical and theoretical basis for the development and design of colored wood-based radiative cooling materials.