The Effects of rGO Content and Drying Method on the Textural, Mechanical, and Thermal Properties of rGO/Polymer Composites

Composite hydrogels samples consisting of poly(methyl methacrylate/butyl acrylate/2-hydroxyethylmethacrylate) (poly-OH) and up to 60% reduced graphene oxide (rGO) containing rGO were synthesized. The method of coupled thermally induced self-assembly of graphene oxide (GO) platelets within a polymer matrix and in situ chemical reduction of GO was applied. The synthesized hydrogels were dried using the ambient pressure drying (APD) and freeze-drying (FD) methods. The effects of the weight fraction of rGO in the composites and the drying method on the textural, morphological, thermal, and rheological properties were examined for the dried samples. The obtained results indicate that APD leads to the formation of non-porous xerogels (X) of high bulk density (D), while FD results in the formation of highly porous aerogels (A) with low D. An increase in the weight fraction of rGO in the composite xerogels leads to an increase in D, specific surface area (SA), pore volume (Vp), average pore diameter (dp), and porosity (P). With an increase in the weight fraction of rGO in A-composites, the D values increase while the values of SP, Vp, dp, and P decrease. Thermo-degradation (TD) of both X and A composites takes place through three distinct steps: dehydration, decomposition of residual oxygen functional group, and polymer chain degradation. The thermal stabilities (TS) of the X-composites and X-rGO are higher than those of the A-composites and A-rGO. The values of the storage modulus (E') and the loss modulus (E") of the A-composites increase with the increase in their weight fraction of rGO.

Graphene and water-based elastomer nanocomposites - a review

Water-based elastomers (WBEs) are polymeric elastomers in aqueous systems. WBEs have recently continued to gain wide acceptability by both academia and industry due to their remarkable environmental and occupational safety friendly nature, as a non-toxic elastomeric dispersion with low-to-zero volatile organic compound (VOC) emission. However, their inherent poor mechanical and thermal properties remain a drawback to these sets of elastomers. Hence, nano-fillers such as graphene oxide (GO), reduced graphene oxide (rGO) and graphene nanoplatelets (GNPs) are being employed for the reinforcement and enhancement of this set of elastomers. This work is geared towards a critical review and summation of the state-of-the-art developments of graphene enhanced water-based elastomer composites (G-WBEC), including graphene and composite production processes, properties, characterisation techniques and potential commercial applications. The dominant production techniques, such as emulsion mixing and in situ polymerisation processes, which include Pickering emulsion, mini-emulsion and micro-emulsion, as well as ball-milling approach, are systematically evaluated. Details of the account of mechanical properties, electrical conductivity, thermal stability and thermal conductivity enhancements, as well as multifunctional properties of G-WBEC are discussed, with further elaboration on the structure-property relationship effects (such as dispersion and filler-matrix interface) through effective and non-destructive characterisation tools like Raman and XRD, among others. The paper also evaluates details of the current application attempts and potential commercial opportunities for G-WBEC utilisation in aerospace, automotive, oil and gas, biomedicals, textiles, sensors, electronics, solar energy, and thermal management.

Latex routes to graphene-based nanocomposites

This review article describes recent advances in the elaboration of graphene-based colloidal nanocomposites by the use of graphene or graphene oxide in heterophase polymerization systems.

Covalently functionalized graphene with d-glucose and its reinforcement to poly(vinyl alcohol) and poly(methyl methacrylate)

Chemically functionalized graphene has been synthesized by covalently grafting d-glucose on graphene for the first time through an esterification reaction.

Crosslinked reduced graphene oxide/polymer composites via in situ synthesis by semicontinuous emulsion polymerization

From aqueous dispersions of crosslinked polymer/reduced graphene oxide (rGO) composite nanoparticles, synthesized by semicontinuous seeded emulsion polymerization, to electrically conductive and reinforced composite films.