title: Exfoliation and chemical modification using microwave irradiation affording highly functionalized graphene.
abstract: Efficient exfoliation of graphite flakes by sonicating them in benzylamine was accomplished, affording stable suspensions of few-layers graphene. The latter were chemically modified following the Bingel reaction conditions, with the aid of microwave irradiation, producing highly functionalized graphene-based hybrid materials. The resulting hybrid materials, possessing cyclopropanated malonate units covalently grafted onto the graphene skeleton, formed stable suspensions for several days in a variety of organic solvents and were characterized by diverse and complementary spectroscopic, thermal, gravimetric, and high-resolution electron microscopy techniques. When a malonate derivative, bearing the electro-active extended tetrathiafulvalene (exTTF) moiety, was synthesized and used for the functionalization of graphene, energy dispersive X-ray (EDX) analysis verified the presence of sulfur in the corresponding graphene-based hybrid material. Moreover, the redox potentials of the exTTF-graphene hybrid material were determined by electrochemistry, while the formation of a radical ion pair that includes one-electron oxidation of exTTF and one-electron reduction of graphene was suggested with the energy gap of (graphene)(•-)-(exTTF)(•+) being calculated as 1.23 eV.
authors.affiliation: Theoretical and Physical Chemistry Institute, National Hellenic Research, Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece.
authors.forename: Solon P
authors.initials: SP
authors.lastname: Economopoulos
authors.forename: Georgios
authors.initials: G
authors.lastname: Rotas
authors.forename: Yasumitsu
authors.initials: Y
authors.lastname: Miyata
authors.forename: Hisanori
authors.initials: H
authors.lastname: Shinohara
authors.forename: Nikos
authors.initials: N
authors.lastname: Tagmatarchis