Self assembly of graphene oxide at the liquid–liquid interface: A new route to the fabrication of graphene based composites

Abstract

Dispersion of graphene in a polymer matrix as mono layers is an important step towards fabricating high performance polymer-graphene nanocomposites. In this paper, a novel method based on Pickering emulsion polymerization has been introduced that assures fine dispersion and enhances loading. The major idea is to use a high affinity of graphene oxide (GO) for assembly at the liquidliquid interface for Pickering emulsion polymerization. A guideline for ensuring stable hybrid colloids of polymer-graphene oxide with an appropriate polymer particle size has been introduced. Then a system of poly (methyl methacrylate) (PMMA)-GO has been selected and the nanocomposites have been made by Pickering emulsion polymerization to examine the theory. TEM studies of the products show various interesting arrangements of PMMA and GO for a different size ratio of nanolayers to polymer particles. The new method paves the way for an environmentally benign process for the production of high quality polymer graphene nanocomposites as it is water-based (no organic solvent is employed) and soap free. Furthermore, resulting hybrid particles were melt mixed with PMMA as a master batch. The resulting nanocomposites with 0.3 wt% graphene showed improved thermal stability and stiffness.

Facile fabrication of self-assembled PMMA/graphene oxide composite particles and their electroresponsive properties

“…The compact GO-sheet layer was suggested to have formed as a result of GO restacking when dispersed in DI water to stabilize the particles. In addition, compared to the broad distributed GO/polymeric particles obtained by Pickering emulsion polymerization [25], the individual particles assembled by GO sheets in this study appeared to be more uniform.…”

“…GO is also used as a surfactant at oil-water interfaces to stabilize the polymeric particles in Pickering emulsions [25], in which the size of the GO sheets is a crucial factor for the preparation of core-shell-structured GO/polymeric particles. If the GO sheets are large, they cannot easily remain at the oil-water interface to stabilize the oil dispersion in the aqueous phase like smaller ones, resulting in small particles adhering randomly to the wide GO sheets.…”

Emerging flexible and wearable physical sensing platforms for healthcare and biomedical applications

“…In general, GO, a hydrophilic derivative of two-dimensional graphene, has been actively explored for a myriad of biomedical and biological applications in recent years 108,109 . With high resistivity 110,111 , low differential conductivity 112 , and low surface tension 113 , GO nanosuspension offers high sensitivity as the active sensing element of the resistive tactile sensor. Interestingly, with this device architecture, our wearable sensing platform was highly flexible, deformable, and capable of withstanding various mechanical deformations, such as pressing, stretching, and bending.…”

Enhancement of dispersion and bonding of graphene-polymer through wet transfer of functionalized graphene oxide

“…Furthermore, colloidal polymer particles may be mixed with GO to incorporate graphene into nonwater soluble polymers [21][22][23][24]. Our recent study also shows GO can be employed as a surfactant in emulsion polymerization to produce polymergraphene nanocomposites [25]. Therefore it is a practical and environmentally friendly strategy, to use aqueous dispersion of GO to produce polymer graphene and GO composites.…”