Ionic-liquid-based polyurethane dispersions for stabilizing graphene in water
Aqueous auto-dispersing polyurethane dispersions (PUDs) have recently been reported to form nanoparticulate dispersions at up to 25% by weight. Their incorporation of an ionic-liquid (IL) monomer, 1-hydroxyundecyl-3-methyl imidazolium bromide (HOC11C1ImBr) as a chain-terminating group appears to account for their auto-dispersing ability, and these PUD nanoparticles bear similarity to IL-based nanolatexes that have provided thermodynamically stable aqueous dispersions of nanocarbons. We demonstrate that these HOC11C1ImBr-based PUDs stabilize aqueous graphene dispersions at 1% by weight graphene in ultrasonicated top-down liquid phase exfoliation. Their formation quantitatively follows an analytical model of exfoliation kinetics of layered materials and a stretched exponential kinetic model. Such dispersions are ideally formulated for making nanocomposites composed of similar or compatible PUDs and other condensation polymers.
Link to Published Version
Gupta, H., & Texter, J. (2019). Ionic-liquid-based polyurethane dispersions for stabilizing graphene in water. MRS Advances, 4(41–42), 2289–2298. https://doi.org/10.1557/adv.2019.328