Enhanced Stability of Reduced Graphene Oxide Colloid Using Cross-Linking Polymers

Reduced graphene oxide (RGO) synthesized by subsequent oxidation and reduction suffers from agglomeration within a few hours/days of its preparation. The stability of RGO is enhanced (no agglomeration for more than 23 months) by allowing two cross-linking polymers that prevent restacking; this increases the solubility and biocompatibility of RGO. The RGO dispersion follows an electrosteric stabilization mechanism. Various theoretical models were adopted to understand this behavior by estimating the potential barrier for agglomeration, surface free energy, and Hansen solubility parameters of the dispersion. As-prepared RGO is found to be biocompatible and has luminescent properties.