Covalent Modification Of Graphene By In Situ SET-LRP And Click Chemistry

Graphene is an allotrope of carbon, whose structure is one atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. Owing to its extraordinary physicochemical and structural properties, this exciting new material has quickly sparked tremendous interests across many disciplines, including nanoelectronics and high-frequency electronics, energy storage and conversion, field emission display, and transparent conductors. Graphene, however, tends to aggregate to form three dimensional graphite with poor solubility in regular solvents, for graphene sheets have strong ultra-molecular force, including Van der Waals force and π-π interaction, which limits its further applications. Chemical modification of graphene has been a promising route to improve its solubility and dispersibility in solvents. Graphene oxide contains a range of reactive oxygen-containing functionalities, which renders it a good candidate for use in the aforementioned applications through chemical functionalization. Polymers are good candidates among those modifiers for graphene. The polymeric part offers dispersibility in certain solvents, mechanical strengthening, and several morphological characteristics, while graphene contributes to the electrical conductivity, chemical reactivity, and reinforcement of the mechanical properties. In this work, we prepared two different graphene/polymer composites with good dispersibility in organic solvents. The details are as follows:(1) We utilized SET-LRP to prepare PDMAA-functionalized graphene by initiating in situ SET-LRP of DMA monomer from the surface of graphene via the ’grafting-from’ strategy. The resulting product revealed that the composites had better dispersibility in organic solvents.(2) PDEAm-functionalized graphene was prepared by combining RAFT polymerization with click chemistry via the’grafting-onto’strategy. The resulting product was well characterized and we found that PDEAm-functionalized graphene possesses good dispersibility in organic solvents.