Preparation Of Graphene Quantum Dot/hydrogenated Nitrile Rubber Composites

Graphene quantum dots are a new class of carbon nanomaterials with a size less than 10 nm.They are widely used in bioimaging,photocatalysis and ion detection because of their good biocompatibility,water solubility and photostability.The surface rich functional groups and regular crystal structure make it potentially useful in composite materials.However,the production efficiency of graphene quantum dots is low and the purification process is complicated,which limits its application in the preparation of composite macromaterials.In this paper,graphene quantum dots are efficiently produced,and their optical and sensing properties are discussed.They are mixed with carboxylated nitrile rubber latex and hydrogenated in situ to obtain hydrogenated nitrile latex composites and processed into film.The main work is as follows:1.The water-soluble graphene quantum dots with good fluorescence effect were developed by microwave assisted heating with trinitroguanidine as the carbon source,and the yield was up to 60.2%.The surface structure and crystal state of graphene quantum dots were characterized by FTIR,XPS,XRD,Ramman and TEM.The yield and quantum yield were higher than those of hydrothermal products.The fluorescence characteristics of different pH environments were studied by exponential fitting of fluorescence intensity and pH,and the potential applications of Fe3+ and Cu2+ concentration detection were explored.2.Using the hydrazine hydrate in the preparation of graphene quantum dots,the hydrogenation of in situ carboxylated nitrile latex was studied to obtain a hydrogenated carboxylated nitrile latex with a degree of hydrogenation of 95%.The stability,dispersibility and fluorescence characteristics of the composite latex were investigated by Zeta potential and fluorescence test.3.The characteristics of composites film formation were studied.The interpenetrating network structure model was established by FTIR,TGA and cross-linking density test.The interpenetrating network structure enhanced the fluorescence intensity of the rubber film and broadened the excitation wavelength to visible light.It was found by fluorescence test that the grafting cross-linking method makes the graphene quantum dots disperse better in the hydrogenated carboxylated nitrile film,and the fluorescence intensity increases with the increase of grafting efficiency.Graphene quantum dots and their formation of interpenetrating network structures enhance the mechanical properties of the film and have better aging resistance.