Preparation And Properties Of Dielectric And Solar-thermal Conversion Materials Based On Graphene

Graphene is a new type of two-dimensional plane nanomaterials which is discovered in 2004. Its special single atomic layer structure determines that it has a large specific surface area, high conductivity and electron mobility at room temperature, as well as excellent mechanical properties. These unique properties make the graphene has great application prospect in the field of electronic, information, energy, materials and biological medicine. How to make use of these unique excellent performance of graphene and to effective the functionalization of graphene, gives new properties to the graphene. It is great importance in graphene further expand application. Therefore, this paper studies in the following: 1、 Using the graphene oxide characteristics of big width ratio and high electric conductivity, prepare conductive/insulation/conductive structure of poly(vinyl alcohol)(PVA)/graphene oxide(GO)/poly(vinyl alcohol) alternating layers polymer composites by the method of spin coating. And the dielectric properties were studied. The research results show that graphene oxide, with big width ratio and high electric conductivity, form many micro capacitance in the polymer. The insulation of pure PVA block the graphene to form conductive path between each other. Therefore, compared with pure PVA materials, the PVA/GO/PVA composite material while maintaining the low dielectric loss can obtain higher dielectric constant. 2、 Using graphene oxide properties of near infrared absorption and poly(N-isopropyl acrylamide)(PNIPA) temperature responsive, prepare GO/PNIPA hydrogel composite material with solar-thermal conversion effect, and the solar-thermal response characteristics are studied. By near infrared(NIR) non-contact laser irradiation, remote control water gel phase transition. Research results show that with the increase of GO fill in the quantity, the response ratio of the hydrogel changes little. Based on NIR irradiation or not, the hydrogel swelling and shrinkage of reversible phase transition will occur. On this basis, it build polyaniline rod tube structure on the surface of graphene oxide in order to improve the GO/PNIPA hydrogel near infrared response ratio, and it applies to the GO/PNIPA solar-thermal conversion materials. Examines the monomer concentration effects on polyaniline surface topography. The result shows that it can build up nanorods structure of polyaniline on the surface of the graphene, through the way of slow reaction. And the effects of monomer concentration on the structure is not great. Such a dense array of nanorods is advantageous to the light refraction and reflection repeatedly, as a result, the polyaniline modification of graphene materials has been higher thermal conversion efficiency; Based on the outstanding solar-thermal conversion performance of those water gel, the preparation of NIR control flow switch is success. In order to obtain multifunctional GO/PNIPA hydrogel material, ferroferric oxide nanoparticles is load on the surface of graphene oxide. And it is apply to the GO/PNIPA solar-thermal conversion material. The multiple response hydrogel materials on temperature and the near infrared is prepared success.