Graphene Oxide–Poly(ethylene glycol) methyl ether methacrylate Nanocomposite Hydrogels

Abstract

In this paper, covalently linked graphene oxide–poly(ethylene glycol) methyl ether methacrylate–reversible addition‐fragmentation chain transfer (GO–PEGMEMA–RAFT) and physically mixed GO–PEGMEMA hydrogel nanocomposites are synthesized. Spectroscopic and imaging techniques such as UV–vis, Fourier transform infrared, Raman spectroscopy, and transmission electron microscopy show that the PEGMEMA is successfully grafted on GO sheets. The rheology of the nanocomposites is studied by small angle oscillatory shear, which shows a competition between reinforcement and lubrication behavior of GO. In the case where lubrication effect dominates reinforcement, the covalently linked GO–PEGMEMA–RAFT has higher G′ compared to the physically mixed GO‐PEGMEMA. Hence, in the covalently linked system, the grafted polymer chains appear to minimize the lubrication effect.

Analysis of dual role of nanographene on the microstructure‐properties correlation of TPU/NG nanocomposite

“…Accordingly, these aggregated particles can activate the lubricating role of graphene more noticeably, resulting in the facilitation of movements of polymer chains and, consequently, a decrease in the elastic response of NC‐1 nanocomposite. A similar observation has been reported by other researchers for the case of GO nanocomposite 38 …”

“…It has been reported that graphene can either act as a reinforcing agent or a lubricant one in a composite system 27,36‐38 . The reinforcement degree of graphene on a polymer matrix is highly connected to the interfacial interaction of graphene and polymer, quality of dispersion of graphene in the polymer matrix, changes in the degree of crystallinity, and also the crystalline structure of polymers in the presence of graphene 39 .…”

“…The reinforcement degree of graphene on a polymer matrix is highly connected to the interfacial interaction of graphene and polymer, quality of dispersion of graphene in the polymer matrix, changes in the degree of crystallinity, and also the crystalline structure of polymers in the presence of graphene 39 . On the other hand, it has been discussed that the lubrication effect is observed when a particular loading of a graphene nanofiller is added 38‐40 . In such a system, lubrication is favored due to the sliding of the graphene sheets on each other, resulting in a significant decrease in the viscosity 37 .…”

Tuning Physical Crosslinks in Hybrid Hydrogels for Network Structure Analysis and Mechanical Reinforcement

“…Herein, we can also achieve χ c (the number of micelles per unit volume) by the following equation [26]:χc=([SDS]Nagg−CMC)*nV…”

Highly Stretchable, Mechanically Strong, Tough, and Self‐Recoverable Nanocomposite Hydrogels by Introducing Strong Ionic Coordination Interactions

“…Thus, improving the mechanical properties and extending the practical applications of hydrogels have been a significant topic in the field of hydrogel science . In this regard, great efforts have been contributed by designing the unique structure and/or introducing effective mechanism for energy dissipation to develop mechanically tough hydrogels, such as nanocomposite (NC) hydrogels, double‐network (DN) hydrogels, tetra‐arm poly(ethylene glycol) hydrogels, slide‐ring hydrogels, microgel‐reinforced hydrogels, and polyampholytes hydrogels …”