The Preparation And Characterization Of Photo-responsive Spiropyran-perylenediimide/Graphene Hybrid

Graphene, a single-atom-thick sheet nanomaterial, has excellent electricity, light,mechanics properties which has triggered enormous interest as a promising.Spiropyran, a well-known photochromic molecule, has been used for thefunctionalization of carbon nanotubes and graphene which makes the design ofgraphene based new optical electronic devices and sensors possible. Therefore, thefunctionalization of graphene modificated with spiropyran derivative has a veryimportant scientific impact.We design a unique spiropyran-perylenediimide which adds the functionalmolecules to adsorption anchor. Not only the molecular can achieve noncovalentattachment of spiropyran photoswitch to graphene via the specially designedadsorption anchor groups, but also the composite maintains good light response whichhas great potential application value. The main research work can be summarized asfollows:1.After hydroxyethyl spiropyran and perylenediimide substituted by fatty acidchains were synthesized according to reported papers, spiropyran-perylenediimide isperformed through esterification between them. The NMR analysis and CHN organicelemental analysis are investigated to evaluate its exact instruct and UV-Visibleabsorption spectroscopy demonstrates its photoresponsiveness ability is fast andstable.2.High quality graphene is prepared by classical liquid-phase exfoliation method.NMP or DMF is selected as the organic exfoliation solvent and ineffective exfoliatedgraphite microchips is eliminated by controlled centrifugation to obtained highconcentration graphene dispersion. TEM、AFM and Raman spectrum reveal thatgraphene is oxide-free and has less defect and less layers.3.After the adsorption between spiropyran-perylenediimide and graphene, theadsorption composite is obtained. FT-IR、 UV and fluorescence quenching areinvestigated to evaluate the successful noncovalent functionalization of the grapheneinstead of blends between spiropyran-perylenediimide and graphene. Several electronmicrographs of the composite show π-π adsorption between them are relativelyhomogeneous.4.Moreover, the switching of complex triggered by UV-visible absorption spectroscopy is demonstrated and its switching ability is preserved over many cyclesof operation and has rapidness response.The innovation of this paper lies in this facile and effective noncovalentadsorption anchor provides a new way of introducing various functional molecules tographene. Moreover, the composite achieves the expected switching propertiesof spiropyran derivatives. Spiropyran modified graphene have potential applicationfor achieving optical switching and new graphene based optical switching devices.