Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of...Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of ammonia and water vapor. The silica films were characterized with TEM, AFM, FTIR, spectrophotometer, ellipsometer, and abrasion test, respectively. The experimental results have shown that the films have a nanostructure with a low refractive index and can form an excellent scratch-resistant broadband anti-reflectance. The two-step catalysis noticeably strengthens the films, and the mixed gas treatment further improves mechanical strength of the silica network. Finally the strengthening mechanism has been discussed.展开更多
Protective fabric has been the focus of research of the textile materials. In recent years, with the rapid development of the robot, its protective fabric has been developed quickly. This paper is making Al, SiO2 as t...Protective fabric has been the focus of research of the textile materials. In recent years, with the rapid development of the robot, its protective fabric has been developed quickly. This paper is making Al, SiO2 as the sputtering target materials, magnetron sputtering as technology, on the back of the fabric sputtering Al layer, double-layer Al/SiO2 film, and three-layer SiO2/Al/SiO2 film through the test of the heat reflectivity of the composite materials. As a result, the highest reflectivity of the SiO2/Al/SiO2, SiO2/Al, and single Al film is 64.97%, 57.38%, and 51.59%, respectively. It is clear that reflectivity increases with the increase of the membrane layer. In three kinds of membrane structures, there are nanometer Al particles in the formation of dense membrane structure, which can improve the reflectivity of the fabric.展开更多
Radiative cooling without energy consumption and environmental pollution holds great promise as the next-generation cooling technology.To date,daytime radiative cooling performance is still slightly low,especially in ...Radiative cooling without energy consumption and environmental pollution holds great promise as the next-generation cooling technology.To date,daytime radiative cooling performance is still slightly low,especially in humid areas.In this work,we demonstrated that nanoporous polyethylene(Nano PE)film can improve solar reflectivity from 96%to 99%,thus boosting radiative cooling performance.Moreover,the experimental results in humid areas indicate that Nano PE films can improve radiative cooling performance by∼76%in a clear day and 120%in a day with few clouds.Additionally,compared with ordinary PE films,thin Nano PE films have significantly higher weather fastness and mechanical strength.More importantly,nano PE films can scatter part of visible light,thus suppressing the generation of light pollution in practical applications.Lastly,the modeling results reveal that with Nano PE films,more than 95%of China’s areas can achieve daytime cooling performance.Our work can boost the development of radiative cooling technology with a very low cost.展开更多
基金the National Natural Science Foundation of China(No:69978017,20133040)Shanghai Key Subject Programme,Chinese Foundation of High Technology(2002AA842052)Shanghai Natural Science Foundation(02ZE14101)as well as Shanghai Nanotechnology Promotion Center(0159um039).
文摘Structural strengthening of the nano porous silica films has been reported. The films were prepared with a base/acid two-step catalyzed TEOS-based sol-gel processing and dip-coating, and then baked in the mixed gas of ammonia and water vapor. The silica films were characterized with TEM, AFM, FTIR, spectrophotometer, ellipsometer, and abrasion test, respectively. The experimental results have shown that the films have a nanostructure with a low refractive index and can form an excellent scratch-resistant broadband anti-reflectance. The two-step catalysis noticeably strengthens the films, and the mixed gas treatment further improves mechanical strength of the silica network. Finally the strengthening mechanism has been discussed.
文摘Protective fabric has been the focus of research of the textile materials. In recent years, with the rapid development of the robot, its protective fabric has been developed quickly. This paper is making Al, SiO2 as the sputtering target materials, magnetron sputtering as technology, on the back of the fabric sputtering Al layer, double-layer Al/SiO2 film, and three-layer SiO2/Al/SiO2 film through the test of the heat reflectivity of the composite materials. As a result, the highest reflectivity of the SiO2/Al/SiO2, SiO2/Al, and single Al film is 64.97%, 57.38%, and 51.59%, respectively. It is clear that reflectivity increases with the increase of the membrane layer. In three kinds of membrane structures, there are nanometer Al particles in the formation of dense membrane structure, which can improve the reflectivity of the fabric.
基金This work was supported by National Engineering Laboratory for Digital Construction and Evaluation Technology of Urban Rail Tran-sit(No.2021HJ01)Tianjin University Innovation Project(No.2020YJSB087).
文摘Radiative cooling without energy consumption and environmental pollution holds great promise as the next-generation cooling technology.To date,daytime radiative cooling performance is still slightly low,especially in humid areas.In this work,we demonstrated that nanoporous polyethylene(Nano PE)film can improve solar reflectivity from 96%to 99%,thus boosting radiative cooling performance.Moreover,the experimental results in humid areas indicate that Nano PE films can improve radiative cooling performance by∼76%in a clear day and 120%in a day with few clouds.Additionally,compared with ordinary PE films,thin Nano PE films have significantly higher weather fastness and mechanical strength.More importantly,nano PE films can scatter part of visible light,thus suppressing the generation of light pollution in practical applications.Lastly,the modeling results reveal that with Nano PE films,more than 95%of China’s areas can achieve daytime cooling performance.Our work can boost the development of radiative cooling technology with a very low cost.
