Study On Ultraflexible Graphene Aerogel Thermal Insulation Material

Graphene aerogel is a kind of porous material with the largest elasticity,the largest specific surface area and the lowest density among carbon aerogels.It has shown great advantages in sensing,catalysis,energy storage,environmental remediation and thermal insulation.In the field of thermal insulation,materials are required to withstand complex stresses and deformations and to have low thermal conductivity,as well as to be able to withstand long-term temperature changes and to have good thermal shock resistance.Since the ultralight structure of graphene aerogels was reported in 2010,due to its excellent mechanical properties(elastic compressive strain>95%),corrosion resistance and flam retardant property,it has shown excellent potential for heat insulation and flame retardant.However,due to the plane-plane π-π stacking in the process of self-assembly of graphene aerogels,when the aerogel is subjected to stretching,bending and twisting,serious structural cracks or even fractures will occur,which greatly limits its application scope.In view of the above problems,this paper carried out the research on the flexible preparation method of graphene aerogel and its thermal insulation performance.The specific research contents are as follows:Ultralight and high elastic graphene aerogel sheets were prepared by hydrothermal method using GO solution prepared by improved Hummers method as precursor.Carbon nanotube aerogel was prepared by chemical vapor deposition with o-dichlorobenzene as carbon source by plankton catalyzing method,and the carbon tube aerogel film was prepared by pretreatment.Graphene oxide ethanol solution was used as adhesive to prepare graphene aerogel material toughened by carbon nanotubes.The excellent interfacial properties and structural integrity of the material were revealed through the elemental and microstructure characterization tests.Combined with the analysis of mechanical properties of graphene aerogel with sandwich structure,and by comparing with the mechanical properties of pure graphene aerogel,it is proved that carbon nanotube aerogel film has excellent toughening properties for graphene aerogel.The sandwich aerogel has excellent mechanical properties.The compressive strain of the material can be up to 99.5%,and it has excellent fatigue resistance.Tensile strength up to 530 kPa,and bending Angle up to 120°.Relevant mechanical theory analysis proved that the structure has excellent overall cooperative deformation ability and interface connection characteristics.The thermal insulation performance of the material was explored,and the influence of the precursor concentration,compression degree and temperature on the thermal conductivity of the material was analyzed.It is found that the thermal conductivity of the material is only 26 mW/(m-K)at room temperature,and is still less than 50 mW/(m·K)at 400℃ and 80%high compression strain,which proves that the material has excellent thermal insulation performance.The electric heating performance of the aerogel was measured,and by comparing the electric heating test results of the traditional graphene electric heating film under low temperature environment,it was proved that the aerogel structure can play an excellent electric heating performance under low power.The research results can be widely used in aerospace,military,machinery,electronics,energy and civil and other fields of heat preservation,flame retardant and thermal management.