功能化石墨烯聚合物简介.pptx

The lack of stable and homogenous dispersion limits its utilization in many potential commercial applications due to the fragile interfacial interaction between the GO or rGO and the host polymer matrix cast from these solvents. To achieve optimum physical and mechanical properties of graphene polymer nanocomposites, the solubility of graphene sheets should be maximized in a common solvent with that of the matrix polymer and the stress transfer should also be maximized through the interface due to the specific interaction between the sheet and polymer matrix. ;The chemistry of functionalization of graphene sheets includes both: (i) covalent and (ii) noncovalent functionalization and depending on its hydrophilic or hydrophobic properties, the modified graphene sheets can be dispersed in specific solvents. The highly soluble and processable graphene sheets can be obtained by grafting the synthetic polymers and also by derivatization of grafted polymers to impart a wide array of functional groups causing stronger specific interaction with the host polymer matrix. ;The GO contains sufficient amount of hydroxyl, epoxy and carboxyl groups; therefore, it is hydrophilic in nature making it incompatible with most hydrophobic polymers. The above functional groups of GO convey opportunity to chemically functionalize with polymers but rGO lacks sufficient functionality for this purpose. Hence, chemical attachment with small molecule containing functional groups brings sufficient functionality facilitating both GO and rGO to give remarkable opportunities for further modification with polymer either by ‘grafting to’ or by ‘grafting from’ techniques. The simple techniques of “grafting to” technique are the direct covalent linkage of the functional polymers on the GO surface using esterification, amidation, click chemistry, nitrene chemistry, radical addition etc. ;Esterification;Amidation;click chemistry;‘Grafting from’ method —— Atom transfer radical polymerization;Fig. 7. Sy