Preparation Of Dopamine-modified Round Flake Graphene Based On Ball Milling And Its Application Properties

Graphene is a perfect newly two-dimension nanomaterials,the critical factor which limited its application is high cost and low yield.There are fatal defects in traditional graphene product methods,such as mechanical peel-off is inefficiency,chemical vapor deposition(CVD)process involves extremely fabrication processes and expensive equipment,and oxide-reduction method only get poor quality product with structure defect.In our study,using cheap pristine graphite through ball-milling treatment in the presence of dry ice to create high pressure environment,which could produce dopamine modified graphene(p-ECG)with special circular morphology and structure in-situ.The effect of high pressure ball-milling process condition on the morphology and structure of p-ECG was intensity established.The application of p-ECG in resin matrix composite reinforcement,surface modified in carbon fiber,anode material of lithium-ion battery was systematically studied.The main work is as follows:1)Research the mechanism and optimum technological condition of p-ECG preparation by high pressure ball-milling.From the experimental results,It's essential the pressure in ball-milling system over 10MPa,the energy of ball-milling system is controlled by the weight of dry ice,the temperature influenced by speed of revolution,ball-milling time in common.Because the edge is more active than basal plane in graphene,the energy provided by ball-milling system could only satisfy the edge of graphene to react with C02 and produce edge-carboxylated graphene(ECG).At the same time,induced an alkalescence condition ball-milling process making dopamine modified graphene in situ,dopamine can react with carboxyl and absorb in graphene surface,generated p-ECG finally.It's essential the pressure in ball-milling system over 10MPa,the energy of ball-milling system is controlled by the weight of dry ice,the temperature influenced by speed of revolution,ball-milling time in common.Because the edge is more active than basal plane in graphene,the energy provided by ball-milling system could only satisfy the edge of graphene to react with CO2 and produce edge-carboxylated graphene(ECG).At the same time,induced an alkalescence condition ball-milling process making dopamine modified graphene in situ,dopamine can react with carboxyl and absorb in graphene surface,generated p-ECG finally.2)Research the application potential of p-ECG composite in mechanics and electricity.The resin matrix composite get the optimal mechanical property and stiffness increased with the content of 0.5wt%p-ECG.p-ECG can enhance electrical conductivity of carbon fiber through adherence in fiber surface to offset defect in T800H carbon fiber.p-ECG improve the fiber-matrix interface through adherence with fiber surface when applied in carbon fiber matrix composite.In anode material of lithium-ion battery,p-ECG can provide high specific area which full contact with electrolyte to shorten the transfer distance of lithium-ion,and increased specific capacity and rate capacity of battery.