Influence of of Network Defects on the Conformational Structure of Nanogel Particles: From Compact 'Closed' to 'Fractal Open' Nanogel Particles

Published

March 4, 2022

Author(s)

Alexandros Chremos, Ferenc Horkay, Jack F. Douglas

Abstract

We propose an approach to generate a wide range of randomly branched polymeric structures to gain insights into the structure of the assemblies to gain general insights into how polymer topology encodes configurational structure in solution. Our work is also motivated by a desire to understand why nanogel particles can either take forms ranging from compact and relatively symmetric sponge-like structures and relatively anisotropic fractal structures such as observed in nanogel clusters and formed by self-associating polymers in solutions such as aggrecan solutions under physiologically relevant conditions. We hypothesized that this spectrum of structures derived from the degree regularity of bonding in the network polymer structure and accordingly we systematically introduced bonding defects in an initially perfect network having a lattice structure in three and two dimensions topological dimensions corresponding to 'sponge' and 'sheet' structures, respectively. The introduction of defects causes these closed and relatively compact nanogel particles to transform near well-defined bond percolation transitions into open nearly fractal objects that have the inherent anisotropy of randomly branched polymers. The mass scaling of the radius of gyration, intrinsic viscosity, and form factor for scattering all undergo abrupt changes that accompany these topological transitions. Our findings support the idea that randomly branched polymers can be considered as perforated sheets. We utilize our model to gain insight into scattering measurements on aggrecan solutions.

Citation

The Journal of Chemical Physics

Volume

159

Pub Type

Journals

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Keywords

randomly branched polymer, sheet polymer, sponge, radius of gyration, hydrodynamic radius, intrinsic viscosity, open and closed gel particles, bond defects

Citation

Chremos, A. , Horkay, F. and Douglas, J. (2022), Influence of of Network Defects on the Conformational Structure of Nanogel Particles: From Compact 'Closed' to 'Fractal Open' Nanogel Particles, The Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933072 (Accessed January 3, 2025)