Progress in Imidazolium Ionic Liquids Assisted Fabrication of Carbon Nanotube and Graphene Polymer Composites

Abstract

Carbon nanotubes (CNTs) and graphene sheets are the most promising fillers for polymer nanocomposites due to their superior mechanical, electrical, thermal optical and gas barrier properties, as well as high flame-retardant efficiency. The critical challenge, however, is how to uniformly disperse them into the polymer matrix to achieve a strong interface for good load transfer between the two. This problem is not new but more acute in CNTs and graphene, both because they are intrinsically insoluble and tend to aggregate into bundles and because their surfaces are atomically smooth. Over the past decade, imidazolium ionic liquids (Imi-ILs) have played a multifunctional role (e.g., as solvents, dispersants, stabilizers, compatibilizers, modifiers and additives) in the fabrication of polymer composites containing CNTs or graphene. In this review, we first summarize the liquid-phase exfoliation, stabilization, dispersion of CNTs and graphene in Imi-ILs, as well as the chemical and/or thermal reduction of graphene oxide to graphene with the aid of Imi-ILs. We then present a full survey of the literature on the Imi-ILs assisted fabrication of CNTs and graphene-based nanocomposites with a variety of polymers, including fluoropolymers, hydrocarbon polymers, polyacrylates, cellulose and polymeric ionic liquids. Finally, we give a future outlook in hopes of facilitating progress in this emerging area. OPEN ACCESSPolymers 2013, 5 848

Enhanced low-temperature lithium storage performance of multilayer graphene made through an improved ionic liquid-assisted synthesis

“…A prominent 2D band at about 2700 cm À1 is also present in both materials. The decrease of the D band intensity in GRAL testifies the obtainment of a graphene with a ordered carbon structure and a low presence of intrinsic defects [29,33]. Similarly, the narrow and less intense G band of GRAL indicates the presence of a sp 2 hybridized crystalline structure, with a low density of defects, which is also supported by the lower I D /I G ratio of GRAL (about 0.183) with respect to that of ES 100 (about 0.237) [29,53e55].…”

“…In contrast, the basal planes are generally free from extrinsic and intrinsic defects [6,7]. During the ultrasonication step, cavitation and shear forces promote p-p and cation-p interactions [32] between the graphene layers of the expanded graphite and the imidazolium cations of the IL [33], thus inducing the exfoliation of MW 100 to thin graphite microplatelets (TG 100) while preventing re-stacking (see TG 100 micrographs in Fig. 1).…”

Thermal properties and non-isothermal curing kinetics of carbon nanotubes/ionic liquid/epoxy resin systems

“…To achieve the advantages of CNTs and to enhance the properties of CNTs/polymer nanocomposites, various approaches are used, such as covalent functionalization and non-covalent functionalization of CNTs [15][16][17]. In recent years, the ability of ionic liquids (ILs) to disperse or modify CNTs has attracted more and more attention [18][19][20][21][22]. Using ILs as dispersant is an effective approach to improve the dispersion of CNTs in a polymer matrix.…”

Investigation of double-layer and pseudocapacitance of surface-modified ionic liquid-functionalized graphene oxide

“…Somewhat more recently, focus has shifted toward developing ionic liquid-functionalized graphene-based materials for supercapacitor electrodes [32][33][34][35][36]. Imidazolium ionic liquids have received possibly the greatest attention for functionalization of graphene-based materials.…”