Preparation Of Graphene Aerogel And Research Of Its Thermal Insulation Property

Graphene has been the focus of research since it was discovered and reported in2004 due to its ultra-high thermal conductivity(5,300 W/m·K),ultra-high electron mobility(15,000 cm~2/V·s)and extremely excellent mechanical properties(young's modulus 1 TPa).Due to its high porosity,large specific surface area and low density,as well as its excellent properties of wave absorption,oil absorption and catalysis,three-dimensional graphene aerogel has attracted extensive attention from scholars.At present,a variety of preparation methods of graphene aerogel have been reported,but the understanding of the assembly process is not deep enough,and the mechanism of action of various factors has not been thoroughly studied.At the same time,there are few studies on the thermal insulation performance of graphene aerogel at this stage.To solve above problems,this article through to the graphene aerogels control of the preparation conditions,and using the scanning electron microscope,Energy Spectrometer(Energy Dispersive Spectrometer,EDS),atomic force microscope,laser thermal conductivity meter testing means,such as comparative analysis of the preparation conditions,raw materials,additives,processing technology of graphene aerogels,macro and micro structure and the effect of oil absorption heat transfer performance and analyzes the mechanism of them.The main research contents include the following aspects:First,graphene aerogels prepared to hydrothermal method,considering the hydrothermal temperature,hydrothermal time,dialysis solution concentration,the amount of ethylenediamine on the influence of graphene aerogels,through to the graphene aerogels morphology observation and characterization of pore structure of the scanning electron microscope,found that increasing,hydrothermal temperature,hydrothermal time water alcohol solution concentration and the addition of ethylenediamine,will cause the graphene aerogels volume contraction and internal diameter reduction.In this paper,the adsorption of organic solvents of graphene aerogel under different preparation conditions was compared and measured.The results showed that the adsorption performance of graphene aerogel to organic solvents decreased with the increase of hydrothermal temperature and hydrothermal time.With the addition of ethylenediamine,the adsorption of graphene aerogel on organic solvent first increased and then decreased.At the same time,the graphene aerogel films with good mechanical properties were obtained by glass sandwich method under optimized preparation conditions.Under the above optimization conditions,the microstructure of graphene aerogel was regulated by changing the concentration of graphene oxide solution,flake graphite diameter and annealing temperature to obtain graphene aerogel with better thermal insulation performance.In this paper,through morphological characterization and comparative experiment of thermal conductivity measurement,it was found that the thermal conductivity of graphene aerogel increased with the increase of GO concentration,flake graphite diameter and annealing temperature,and the mechanism of various influencing factors was analyzed.In addition,for the more intuitive to observe all the conditions on the heat transfer performance of graphene aerogels,this article also measured the graphene aerogels in the control group of 200?,250?,300?under the condition of heating temperature gradient,and has carried on the comparison and analysis.In order to reduce the heat transfer capacity of graphene sheet layer,the thermal insulation performance of graphene aerogel was improved.This article also graphene oxide as the precursor,incorporation of phenylene diamine and ammonia to introduce amino group,through the water thermal gas nitrogen impurity fossil ink gel preparation,and by using scanning electron microscopy(SEM),instruments and equipment,such as the laser thermal conductivity meter of nitrogen impurity fossil ink gas gel microstructure,phase composition,the coefficient of thermal conductivity of characterization,and corrosive phenylenediamine doped graphene aerogels are analyzed in comparison.