Study On The Structure And Properties Of Large-scale Graphene Oxide-carbon Nanotube Aerogel/polystyrene Nanocomposites

Graphene oxide and carbon nanotubes have high specific surface area,high surface energy and other excellent properties.Graphene oxide / carbon nanotubes / polymer composites have good strength,elasticity,fatigue resistance and other properties,and are widely used in many fields.However,because the dispersion of nano materials limits the development of some properties,graphene oxide carbon nanotubes aerogels can effectively solve the dispersion problem of nanomaterials in polymers.The preparation of graphene oxide carbon nanotubes aerogels is a freeze-drying process.When water freezes,the formation of ice particles is difficult to form homogeneous aerogels,which seriously affects the final performance of composite materials.For many years,researchers have only made small size columnar aerogels for the preparation of composite materials,ignoring or avoiding the serious problem,and can only study the non-standard properties of composites such as compression,and so far have not been involved in many other mechanical properties and electrical and thermal properties of standard tests.Therefore,breaking through this key technology bottleneck,it is imminent to prepare graphene oxide carbon nanotube aerogels and polymer composites with large size,which can perform various standard performance tests and have uniform nano interpenetrating network nanostructures.Aiming at the problem that graphene oxide carbon nanotubes are not easy to disperse in polymer matrix,large size graphene oxide(GO)-carbon nanotubes(CNT)aerogels(GOCA)with three-dimensional network structure are first prepared,and effectively solve the problem of ice produced by large size GOCA,and further enhance the skeleton by GOCA.Polystyrene composite(GOCA/PS)was formed in the aerogels by in-situ polymerization.The effects of the ratio of GO to CNT and the mass content of GOCA in the composites on the properties of GOCA/PS composites were studied.The main research contents are as follows:(1)Three dimensional GOCA was prepared by freeze-drying of go and CNT.The mixture of styrene and initiator was polymerized in situ in the three-dimensional goca prepared by freeze-drying to form GOCA/PS.After heat treatment,GOCA/PS nanocomposites have excellent mechanical properties.The results show that GOCA can be well dispersed and embedded in PS matrix.When the mass ratio of GO to CNT is 7:3 and the total load of GOCA is 1.02wt%,the tensile,flexural,compressive and impact strength of the material are greatly improved(64.05%,54.7%,107.38% and66.5% higher than that of pure PS,respectively).Meanwhile,the prepared GOCA/PS nanocomposites have a micro hardness of 265 MPa and a compression modulus of689 MPa.Therefore,GOCA can effectively enhance the mechanical properties of PS.(2)Three dimensional GOCA was prepared by freeze-drying of GO and CNT.Then in situ polymerization of styrene in GOCA was carried out to prepare GOCA/PS nanocomposites.The effect of GO/CNT ratio on the properties of the composite was studied.The results show that when the total amount of goca is 1.0wt%,the ratio of GO to CNT is 7:3,the mechanical properties(tensile,bending,impact and compression strength)of GOCA/PS nanocomposites are the best.These methods provide an effective way for the design and research of reinforced composite materials.(3)Three dimensional GOCA was prepared by freeze-drying of GO and CNT,and then the mixture of styrene and initiator was polymerized in situ in GOCA to form large-scale GOCA/PS nanocomposites.In addition,we also controlled the pore size of GOCA in composites by adjusting the mass content of GO and CNT,and evaluated the effect of aerogel pore size on the mechanical properties of GOCA/PS nanocomposites.The results show that when the total amount of GOCA is about 1.1%and the ratio of GO/CNT is 7:3,the GOCA/PS nanocomposite has the best mechanical properties,and the aerogel has the best pore size and uniformity.With the increase of GO and CNT ratio in the composites,the pore size of aerogels showed a regular change.Tensile strength,bending strength,impact strength and compressive strength increased first and then decreased.Through our research,we successfully solved the icing problem in the preparation process of large-scale goca,and then poured styrene monomer,in-situ polymerized and molded to prepare large-scale goca / PS nanocomposites,which solved the dispersion problem of carbon nanomaterials in the polymer matrix.At the same time,the tensile and bending properties of the composites were tested according to the national standards,The relationship between the structure of aerogels and the properties of composites was studied.