Study On Preparation?Properties And Application Of Grapheme/Nanofiber Composite Aerogel

In this paper,we studied the preparation of graphene aerogel and its application on the basis of the three-dimensional assembly and the properties of graphene sheet.Because the structure of grapheme aerogel is easy to collapse,using nanofiber to mechanical enhancement the graphene aerogel and explore the change of macroscopic mechanical properties,pore structure and electrical properties.Study the application of composite aerogels in the field of organic pollutants adsorption,thermal insulation and pressure sensingUsing ethylenediamine reduce the graphene oxide which prepared by Hummers method in the hydrothermal synthesis get grapheme hydrogel.After freeze-drying the good internal structure and electrical conductivity aerogel be prepared,explore the impact of freezing conditions on the microstructure and macroscopic morphology of aerogel materials of aerogel.Through the directional freeze-drying technique,the good internal structure of the graphene aerogel was prepared.Meanwhile,an aerogel-based pressure sensor was also set up to study its sensitivity and stability.The result show that the aerogel-based pressure sensor has good conductive,excellent sensitivity and outstanding stability and the response time of pressure sensor was about 0.5s when the pressure is about 0.5N.However,the mechanical properties of aerogel are poor and the structure is easy to collapse,so the application is limited.Improvement of the mechanical properties of graphene aerogels by nanofibers.By using the method of physical crosslinking with PVA get the nanofiber aerogel with excellent mechanical properties.Explore the influence of crosslinking agent content on microstructure,morphology and mechanical properties of nanofiber aerogel.The result show that when the content of PVA was 0.4% the performance of the aerogel is best,and it could be used in the field of high efficiency air filtration.The filtration efficiency of 0.3um NaCl particles is more than 99% and the pressure drop is only 62 Pa.After chemical modification by methyl trichlorosilane the aerogel become lipophilic and hydrophobic.The oil absorption rate of colza oil reached 4200% and the elastic recovery become 100%,thus the aerogel can be used in the aero of oil-water separation and oil spills.The composite aerogel made by graphene and nanofiber.There are a special structure that nanofiber as the framework and the graphene as the lamellae.This structure improve the mechanical properties of grapheme aerogel,at the same time,has good conductive.The optimum preparation process was obtained by studying the microstructure,morphology and reduction degree of the composite aerogels prepared by different preparation processes.