1. Colloidal stabilization of graphene sheets by ionizable amphiphilic block copolymers in various media
- Author
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Popescu, Maria-Teodora, Tasis, Dimitrios, Papadimitriou, Konstantinia D., Gkermpoura, Sandra, Galiotisac, Costas, and Tsitsilianis, Constantinos
- Subjects
Condensed Matter - Materials Science - Abstract
In this work, linear polystyrene-poly(2-vinylpyridine) (PS-b-P2VP) and heteroarm star PS_22P2VP_22 ionizable block copolymers were used as dispersing agents for the liquid-phase exfoliation of pristine graphene. Various strategies such as direct exfoliation, film hydration and phase transfer have been employed and compared. The best strategy involved a two-step process, namely, pre-exfoliation of graphite in polymer/CHCl3 solutions followed by phase transfer to acidified water. High concentrations of stable aqueous suspensions of graphene flakes, highly enriched in monolayer structures, were then obtained by using the star-shaped copolymers as stabilizers. The as-prepared graphene/copolymer hybrids were used as a filler material in order to prepare functional polymer composites for mechanical reinforcement. Such copolymer-modified graphene sheets have proven to be efficient reinforcing agents of PVA, as a significant increase of storage modulus (145% higher than that of neat PVA) was achieved even at a low graphene weight fraction of 0.1 wt%.
- Published
- 2018
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