Structure and conformational properties of perfect nanogel particles in athermal solutions

Published

October 5, 2021

Author(s)

Alexandros Chremos, Ferenc Horkay, Jack F. Douglas

Abstract

Conformational properties of 'perfect' nanogel particles having a lattice network topology by molecular dynamics simulations to quantify the influence of polymer topology on the solution properties of this type of branched molecular architecture. In particular, we calculate the mass scaling of the radius of gyration and the hydrodynamic radius, as well as, the intrinsic viscosity with the variation of the degree of branching, the length of the chains between the branched points, and the average mesh size within the nanogel particle under good solvent conditions. We find competing trends between the molecular characteristics, where an increase in mesh size or degree of branching results in the emergence of particle-like characteristics, while an increase in the chain length enhances the linear polymer-like characteristics. This crossover between these limiting behaviors is also apparent in our calculation of the form factor, P (q), for these structures. Specifically, a primary scattering peak emerges characterizing the overall nanogel particle size. Moreover, a distinct power law regime emerges in P (q) at length scales larger than the chain size, but smaller than the Rg of the nanogel particle and the scaling exponent for this power law regime goes to zero as the mesh size increases. The latter feature is not captured by the 'fuzzy sphere' model, and we propose an extension to this popular model. These structural features become more pronounced for values of molecular parameters that lead to enhance the localization of the branching segments within the nanogel particle.

Citation

Journal of Chemical Physics

Issue

13

Pub Type

Journals

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Keywords

perfect gel, polymer network, nanoparticle, fuzzy sphere, hydrodynamic radius, intrinsic viscosity, radius of gyration, configurational properties, good solvent

Citation

Chremos, A. , Horkay, F. and Douglas, J. (2021), Structure and conformational properties of perfect nanogel particles in athermal solutions, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=932888 (Accessed April 29, 2024)