The Preparation And Performances Of Graphene Based Aerogels By Interfical Reinforcement

Recently,graphene aerogels received widespread attention due to their excellent performances,such as low density,high conductivity and superelasticity.Although lightweight three-dimensional(3D)graphene aerogels combining ultrahigh electrical conductivity,superelasticity,and fatigue resistance are highly desirable for widespread applications,such as electromagnetic interference(EMI)shielding materials,pollutant absorption materials,and electron devices,it is still difficult to prepare lightweight graphene aerogels with excellent conductive and mechanical properties.The weak physical interactions between highly reduced graphene sheets result in poor mechanical performances for graphene aerogels due to the elimination of oxygen functional groups on the surface.Howeve,the patially reduced graphene sheets in aerogels lead to poor conductive properties.Therefore,it remains a huge challenge to construct a multifunctional graphene framework which can afford the rapid electron transport and efficient load transfer simultaneously.In this work,we proposed a facil strategy for fabricating integrated graphene aerogels by interfical reinforcement of graphitized carbon.The specific details are as follows:1.An interfical reinforcement strategy is proposed.After the graphitization,the graphene oxide sheets are thermally reduced to graphene efficiently by ultimately removing the oxygen-containing groups and healing their defects,while the polyimide component is graphitized to form turbostratic carbon to bridge the graphene sheets,resulting in an intergrated graphene aerogel with satisfactory mechanical and electrical perfomances.Moreover,the shape and size of the aerogels can be easily controlled due to the facile fabrication procedure.2.The as-prepared intergrated graphene aerogel presents a sequence of intriguing properties,such as superelasticity and high electrical conductivity of 1000 S m-1 at a low density of 7.6 mg cm-3.Due to the ultrahigh conductivity,the graphene aerogel shows an unprecedented electromagnetic interference shielding performance of?83 dB in X-band at a thickness of 2 mm and the specific shielding effectiveness reaches up to 4703 dB cm3 g-1.3.Because of the interface reinforcement by the graphitic carbon,the higly conductive graphene network is well welded into an integrated structure with excellent structural robustness.The aerogel possesses 90%reversible compressibility and reliable resistance to fatigue for 1000 compressive cycles at 50%strain.Attributed to the combination of high conductivity and elasticity,the aerogel also shows its potential in applications of strain sensors.4.The intergrated graphene aerogel also pocesses excellent organic solvent absorption performance as evidenced by its hydrophobicity and porous structure.The maximum absorption capability can be 167 times of its own weight for the collection of chloroform.Additionally,the robust,porous and intergrated graphene framework presents excellent durability and recyclability in liquids.