Preparation Of Graphene Materials And Their Applications In Supercapacitors And Temperature Sensitive Smart Devices

Graphene as a new type of two-dimensional material is a single layer of carbon atoms through the sp~2 hybrid formed by the covalent bond composed of two-dimensional layered structure.Since its debut,it has attracted many researchers,interests Because of its excellent electrical properties,optical properties,mechanical properties and mechanical properties.In this paper,we used flexible natural silks as template,through a simple direct spraying method to deposite the enriched graphene solution on the silks template.And then,the hydroiodic acid was used as reduction and corrosive masterly,during the reductive process of graphene oxide fiber,the silks template which was in the internal of the graphene fiber was etched away,and obtained flexible hollow graphene fiber successfully.At the end,this flexible hollow graphene fiber was used as the electrode to prepare a symmetrical all-solid-state flexible graphene fiber supercapacitor.The prepared all-solid-state flexible graphene fiber supercapacitor has excellent capacitance performance.Considering the combined merits of cost-effeciency and large-scale availability of chemically prepared graphene and the simple,green and controllable fabrication process,these flexible,hollow and conductive graphene fibers are particularly promising for the fabrication of flexible and wearable electronics.Then,a two-dimensional CVD graphene film was prepared by CVD method.And the thermo-sensitive poly(N-isopropylacrylamide)(PNIPAAm)containing pyrene functional group was prepared by RAFT polymerization method.We have successfully synthesized graphene-PNIPAAm composite films that can be utilized as thermo-responsive actuators.The composite films were facilely prepared by non-covalent ?-? stacking interactions between CVD graphene and pyrene terminated PNIPAAm,and the latter was synthesized via RAFT polymerization uisng a pyrene terminated RAFT agent.The lower critical solution temperature(LCST)of PNIPAAm endowed the CVD graphene-PNIPAAm with controllable thermo-responsibility.When the temperature was manipulated above or below 32 oC the graphene-PNIPAAm composite films exhibited reversible deformation behavior.To demonstrate the application,the CVD graphene-PNIPAAm film was applied to fabricate a LED light switch to thermo-control the light on or off.This convenient ?-? stacking modification methodology for the preparation of graphene composites could be generalized to the preparation of other graphene-based stimuli-responsive actuators and sensors.