(476c) Modular Self-Assembly of Metal/Polymer Nanoreactors

Harrison, A. - Presenter, Virginia Commonwealth University
Vuong, T., Virginia Commonwealth University
Zeevi, M., Virginia Commonwealth University
Hittel, B., Virginia Commonwealth University
Tang, C., Virginia Commonwealth University
Self-assembled structures such as micelles and vesicles that confine catalyzed reactions to the hydrophobic core of micellar nanoreactors can facilitate organic phase reactions in a bulk aqueous environment. Flash NanoPrecipitation is a rapid, scalable, and modular method capable of continuously producing such structures. We have explored the use of Flash NanoPrecipitation (FNP) as a platform technology to rapidly self-assemble kinetically trapped core-shell polymer nanoreactors that incorporate catalytic gold nanoparticles within tunable hydrophobic microenvironments. Specifically, nanoreactors using polystyrene, dodecane, dodecanethiol, or dodecylamine have been achieved to investigate the effect of core-catalyst interactions as well as the phase (liquid vs. solid) of the microenvironment on reaction kinetics using reduction of 4-nitrophenol as a model reaction. Both dodecanethiol and dodecylamine nanoreactors did not catalyze the 4-nitrophenol reaction. This is likely due to the interaction of the amine and thiol moieties with the gold nanoparticle surface, effectively blocking catalytic active sites. Dodecane nanoreactors catalyzed the reaction with an apparent rate constant of 0.049 ± 0.012 s-1 cm-2. Interestingly, nanoreactors with a dodecane core showed 10-fold shorter induction time and 2-fold faster kinetics than polystyrene cores. These results demonstrate that the microenvironment of the nanoreactor can have a dramatic impact on reaction kinetics, possibly due to reagent solubility. Thus, the effect of reactant permeability on overall nanoreactor performance will be discussed.