Preparation And Properties Of Gradient Index Photothermal Conversion Glass Films

In recent years,solar technology has become especially important due to the shortage of energy,which has led to the rapid development of various photothermal conversion materials,and has a very broad application prospect in the fields of biomedicine,environmental pollution and seawater desalination.How to overcome the low utilization rate of solar energy and enhance the intensity of light absorption,and to explore new and efficient photothermal conversion materials has always been a hot research topic.In this paper,a gradient index structure is proposed to be introduced into carbon-based materials.The function of reducing reflection and increasing transmission through this structure promotes the material at the bottom to absorb more photons,enhances the light absorption ability and improves the photothermal performance of the material.By changing the type of matrix glass,selecting different carbon-based photothermal materials,and doping TiO₂,the photothermal properties of three different series of photothermal composite materials and the influence of various factors are studied and analyzed.The specific research work of this paper is as follows:The first chapter,the introduction part gives a detailed introduction to the development status,types,photothermal conversion mechanism,application development history and potential problems of photothermal conversion materials.The second chapter,in order to reduce the preparation cost and improve the recycling rate,according to the characteristics of screen printing that can control the refractive index composition and structure,combined with low-temperature sintering at 575℃,the tellurium-zinc gradient refractive index graphene material is prepared.The composition design of the tellurium-zinc matrix glass is introduced.The structure of gradient index photothermal conversion materials and the principle of improving photothermal performance are analyzed.Based on the principle and formula of the structure,the optimal gradient refractive index structure of tellurium-zinc system composed of TZW1-TZW3 is designed on the glass plate,which lays a foundation for the preparation of refractive index photothermal composite materials.Through experimental tests,it is found that the samples prepared by screen printing have certain light absorption characteristics,and the absorption value is between 0.7-0.75.Under the irradiation of 980 nm laser,the sample can rapidly convert the absorbed light into heat,making the surrounding temperature as high as 48℃.And this preparation method is simple and novel,easy to popularize.The third chapter,in order to increase the functionality and application of disordered mesoporous carbon materials and further improve the photothermal properties of the materials,bismuth telluride gradient index disordered mesoporous carbon materials are synthesized based on bismuth telluride matrix glass by introducing gradient index structure.The changes of photothermal properties of the composite with the concentration of disordered mesoporous carbon under 808 nm laser irradiation are studied.At the same time,the composite has good photothermal stability.The greater the light absorption intensity of the photothermal conversion material,the better the photothermal conversion effect.Through the experimental comparison of the properties of the disordered mesoporous carbon material without refractive index structure,it is found that the absorbance of the refractive index photothermal material increases by 0.212 and the measured temperature increases by 9.375℃,which fully verifies the effectiveness of combining the gradient refractive index structure to improve the properties of the photothermal material.The fourth chapter,in order to improve the diversity of disordered mesoporous carbon photothermal composites,the effects of various factors on their photothermal properties are studied,and the photothermal effect of refractive index disordered mesoporous carbon materials is further improved.The gradient refractive index TiO₂/disordered mesoporous carbon material of lithium silicon system is prepared by doping TiO₂and changing the type of matrix glass to lithium silicon system glass.The light absorption characteristics of the photothermal composite are different at different wavelengths,and the photothermal properties are also different.Compared with the results of white light and 808nm laser,the sample has the most heat release under 980nm laser.At the same time,the higher the laser power,the better the photothermal performance,and the maximum temperature can reach nearly 55℃.In addition,after optimizing the doping mode of TiO₂,the absorption value of the sample increases by nearly 0.0836 compared with the original doped TiO₂.Compared with the disordered mesoporous carbon with gradient refractive index of lithium silicon system without TiO₂,its temperature is significantly increased by about 6.5℃,and the photothermal performance of the optimized sample is better.This series of research fully shows that this series of composites have great development prospects in the field of photothermal.The fifth chapter summarizes the research content of the full text,and looks forward to the development and shortcomings of several new photothermal composites.