Rana Ashraf Elsayed Essa

Microwave-assisted synthesis of Silicon/Carbon nanocomposites as thermal and electrical capacitors / تحضير متراكبات السيليكون / كربون النانوية بمساعدة الميكروويف كمكثفات حرارية وكهربائية Rana Ashraf Elsayed Essa ; Supervised Yasser Attia Attia , Shymaa Samir Mohamed Medany ,Yasser Mahmoud Ali Mohamed - Cairo : Rana Ashraf Elsayed Essa , 2020 - 193 P. : charts , facsimiles ; 25cm

Thesis (M.Sc.) - Cairo University - National Institute of Laser Enhanced Sciences (NILES) - Department of Laser applications in Enviromental Merology Photochemistry and Photobiology and Agriculture

In this study, we evaluate the effectiveness of silicon/carbon nanocomposites as thermal and electrical capacitors. Silicon/RGO and Silicon/GO nanocomposites were prepared by using a simple microwave-assisted method for the hybridization of reduced graphene oxide and graphene oxide with trimethylsilyl chloride (TMSCl) and tert-butyl diphenylsilyl chloride (TDPSCl).The assynthesized silicon-functionalized reduced graphene oxide (RGO) and graphene oxide (GO) materials (TMS/RGO, TDPS/RGO, TMS/GO and TDPS/GO) were characterized using spectroscopic techniques to show the anchoring of silicon on the sheets of the reduced graphene oxide and graphene oxide.The structures of these materials comprised of nanosheet of carbon attached to hydroxyl, carboxylic and epoxy functional groups. One way of increasing the thermal conductivity of these materials is improving VI thermal stability, decreasing the surface energy, and increasing the chemical stability that offer a good hydrophobic surface due to the action of TMS and TDPS as protecting agents that will enhance the crystallinity and chain alignment and thereby facilitate the movement of heat-conducting phonons.Therefore, we sought in this study to functionalize the RGO and GO surfaces with silicon with [C-O-SiR3, C-COOSiR3, C(OSiR3)-C(OSiR3)] functional groups.TEM was used to show the morphology of the particles which were further analyzed using XRD, FTIR, and DRS. The thermal capacitance was evaluated using TGA and DSC. While GO and RGO have volumetric capacities of 2653.22 oV.s/mg and 89.7 oV.s/mg respectively, RGO/TDPS showed a capacity of 5507.85 oV.s/mg and RGO/TMS showed an even higher capacity of 7473.03 oV.s/mg.



Graphene oxide Reduced graphene oxide Silicon/graphene oxide hybrids