Interlayer Polymerization in Chemically Expanded Graphite for Preparation of Highly Conductive, Mechanically Strong Polymer Composites

Abstract

The large-scale application of graphene–polymer composites needs a simple, low-cost method that simplifies the preparation process of graphene and optimizes the structure and properties of composites. We propose the first interlayer polymerization in chemically expanded graphite (CEG) with large specific surface areas, which allows CEG to be spontaneously exfoliated into single- and few-layer graphene in poly­(methyl methacrylate) (PMMA). Our results demonstrate that besides weakened interlayer interactions, the surface wettability of CEG to monomers is a critical prerequisite for the desired graphene exfoliation, dispersion, and performance optimization of composites. The slightly oxidized CEG (LCEG) improved to some extent the affinity for the monomer but is not sufficient to achieve complete exfoliation of LCEG, so that the resulting composites reveal the mechanical and electrical properties that are far poorer than those of the surface-modified LCEG-based composites. The latter not only exhibit a significantly enhanced elastic modulus, increased as much as 3-fold relative to that of the neat PMMA, but also show an extremely high electrical conductivity, of >1700 S/m. Such a novel interlayer polymerization approach is expected to accelerate the use of industrial applications of a wide range of graphene-based composites.

Evaluation of multi-layered graphene nano-platelet composite coatings for corrosion control part I - contact potentials and gas permeability

“…The theoretical surface area of single layer graphene has been reported to be roughly 2600 m 2 /g [1] and the interlayer spacing of multilayer graphene has been shown to be 0.34 nm [41]. From these quantities, combined with the N 2 BET specific area for our GNP sample we can calculate a mean platelet thickness of 155 nm (+/-5.…”

Nonmainstream Out‐Plane Fluoro‐ and Amino‐Cofunctionalized Graphene for a Striking Electrocatalyst: Programming Substitutive/Reductive Defluorination toward Graphite Fluoride

“…To this end, 1‐bromohexane, as a typical electrophile, is reacted with the NH 2 GF 9 sample. The yielded product is subjected to FT‐IR's inspection, which distinctly exhibits a couple of new peaks at 2922 and 2850 cm −1 ascribed to characteristic aliphatic CH stretching vibrations (Figure a) . This finding verifies that n ‐hexyl addends are successfully coupled with NH 2 moieties of NH 2 GF 9 , and indicates that NH 2 GF possesses the candidacy of GO alternative and provides many exciting opportunities in graphene functionalization.…”

Thermodynamically Metal Atom Trapping in Van der Waals Layers Enabling Multifunctional 3D Carbon Network

“…In fact, graphitic structure can be sheared parallel or expanded normal to the in-plane direction through two commonly accepted mechanisms: 1) the migration of molecules between vdW gaps; 2) the introduction of functional groups on the surface of vdW monolayer by mild oxidation process. [17][18][19][20][21][22][23][24][25] However, these two pathways generally require long-term reaction (totally over 12 h), harsh conditions (e.g., concentrated H 2 SO 4 , H 2 O 2 , and KMnO 4 etc. ), and complex synthetic procedures, due to the low coordination efficiency of alien molecular/ functional groups in graphitic structure.…”