Experimental Study On Heat Radiation Characteristics Of Graphene Paper

As an emerging graphene-based material,graphene paper is widely used in sensors,transistors,clean energy batteries and heat dissipation composites based on its excellent thermal and electrical properties.In the past thermal research,its high thermal conductivity has been applied more.In the radiation devices of new infrared radiation sources or broad-spectrum infrared absorbers,the thermal radiation characteristics of graphene paper play a leading role in the modulation of the overall optical and thermal properties.Therefore,it is very important to explore the radiation characteristics of graphene paper for the analysis of the physical properties of materials and the application of energy-consuming materials.The paper mainly explores the radiation characteristics of graphene paper under different temperatures and surface structures.First,the measurement principle and method under normal temperature and temperature rise conditions were given.Based on Kirchhoff’s law at room temperature,the measurement was performed using an integrating sphere attachment of a Fourier infrared spectrometer.At the time of temperature rise,based on the energy method,the emissivity measurement accessory was first used,and the measurement system was constructed by self-made standard black body;A self-made external heating device was used to build a sample heating system.Based on this,a method for measuring the spectral emissivity of large-sized opaque samples was established.Secondly,the variation law of spectral emissivity of graphene paper under different temperature and temperature conditions was studied.At normal temperature,the surface normal spectral emissivity and the characteristics of accurate diffuse reflection and specular reflection were analyzed.Then,as the temperature rising,based on the developed heating system,the radiation characteristics of the sample surface were analyzed by indirect heating and direct current heating.At the same time,the spatial distribution characteristics of the spectral emissivity of large-scale graphene paper were studied,and the error analysis of different heating methods was carried out.It was found that under different heating methods,the surface emissivity of graphene paper increased between about 2.5-9.5 μm,decreased between 10.5-20 μm,At 9.5-10.5 μm,there was a intersection of the emissivity did not change with temperature,and the emissivity was evenly distributed.Thirdly,the surface of the graphene paper was etched using the plasma.The effects of the changes in the surface structure of graphene paper on the full-band normal spectral emissivity in different etching modes in oxygen and argon atmospheres were investigated.When chemical etching was performed under an oxygen atmosphere,the surface structure of the sample did not change greatly as the etching time increases.The layer-layer etching made sample thin and the emissivity unchanged.When the physical etching was performed under an argon atmosphere,the surface of the sample was bombarded with the protrusion of about 50nm.Finally,based on the laser etching method,the effects of one-dimensional grating structure and two-dimensional well-word grid structure on the spectral emissivity of graphene paper surface were studied.In the one-dimensional grating structure,the sample was directly energized and heated by changing the etching power and the etching interval,comparing the the variation law of the spectral emissivity after surface structure changes caused by the grating groove depth and interval change,and changing the energization direction by the same structure;As the depth of the groove increased,the emissivity increased;the change in the direction of energization did not cause a change in the emissivity,and the surface emission of the graphene paper did not change as a whole at different etch intervals.In the two-dimensional well-word grid structure,the characteristics of the spectral emissivity of the samples used the same etched structure under indirect and direct energization heating conditions were investigated.Under different heating conditions,the emissivity was basically the same when the temperature was close,and the emissivity increased with the increase of temperature.At the same time,in the two etching structures,the surface temperature of the large-sized grating structure graphene paper was uniform when heated.