2020 Virtual AIChE Annual Meeting
(267c) Structure and Phase Behavior of Polyelectrolyte–Nanoparticle Assemblies
Authors
Advait Holkar, University of California, Los Angeles
Jesse Toledo, University of California, Los Angeles
Aqueous mixtures of oppositely charged polyelectrolytes (PE) and nanoparticles (NP) self-assemble into dense complexes. This self-assembly forms the basis of diverse phenomena ranging from flocculant action in water treatment, where the PE-NP flocs phase separate and sediment, to DNA compaction around histone proteins into chromatin. Factors such as the PE length, architecture and concentrations; NP charge, morphology and concentrations; and solution conditions (pH and ionic strength) play key roles in directing these PE-NP assemblies. In this presentation, we will delineate fundamental investigations into the phase behavior and structure of polyelectrolyte-NP assemblies using small angle X-ray scattering, turbidimetry and thermogravimetric analysis with systematic variation of PE sizes and flexibility, NP sizes, and a wide range of concentrations of both components. Trends in interparticle spacings and correlations as well as fractal dimensions of assemblies with varying PE and NP concentrations will be discussed, presenting a comprehensive narrative of the hierarchical structure of PE-NP self-assemblies. Universal trends in compaction of NPs in the PE-NP assemblies as a function of ratio of PE and NP concentrations will be highlighted.