Structure and Dynamics of Hybrid Colloid-Polyelectrolyte Coacervates: Insights from Molecular Simulations.

Autor:	Yu B; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States., Liang H; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States., Nealey PF; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States., Tirrell MV; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States.; Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States., Rumyantsev AM; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States.; Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695-7905, United States., de Pablo JJ; Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States.; Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, United States.
Jazyk:	angličtina
Zdroj:	Macromolecules [Macromolecules] 2023 Sep 05; Vol. 56 (18), pp. 7256-7270. Date of Electronic Publication: 2023 Sep 05 (Print Publication: 2023).
DOI:	10.1021/acs.macromol.3c01079
Abstrakt:	Electrostatic interactions in polymeric systems are responsible for a wide range of liquid-liquid phase transitions that are of importance for biology and materials science. Such transitions are referred to as complex coacervation, and recent studies have sought to understand the underlying physics and chemistry. Most theoretical and simulation efforts to date have focused on oppositely charged linear polyelectrolytes, which adopt nearly ideal-coil conformations in the condensed phase. However, when one of the coacervate components is a globular protein, a better model of complexation should replace one of the species with a spherical charged particle or colloid. In this work, we perform coarse-grained simulations of colloid-polyelectrolyte coacervation using a spherical model for the colloid. Simulation results indicate that the electroneutral cell of the resulting (hybrid) coacervates consists of a polyelectrolyte layer adsorbed on the colloid. Power laws for the structure and the density of the condensed phase, which are extracted from simulations, are found to be consistent with the adsorption-based scaling theory of hybrid coacervation. The coacervates remain amorphous (disordered) at a moderate colloid charge, Q , while an intra-coacervate colloidal crystal is formed above a certain threshold, at Q > Q *. In the disordered coacervate, if Q is sufficiently low, colloids diffuse as neutral nonsticky nanoparticles in the semidilute polymer solution. For higher Q , adsorption is strong and colloids become effectively sticky. Our findings are relevant for the coacervation of polyelectrolytes with proteins, spherical micelles of ionic surfactants, and solid organic or inorganic nanoparticles. Competing Interests: The authors declare no competing financial interest. (© 2023 The Authors. Published by American Chemical Society.)
Databáze:	MEDLINE
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