Processing-Dependent Interfacial Conformation of Adsorbed Polymers Induces Divergent Equilibration in Chemically Identical Polymer Nanocomposites
Year: 2026
Type: article
Abstract: Polymer nanocomposites (PNCs) are recognized for their enhanced mechanical, thermal, and functional properties, but their behavior is not always dictated by chemistry. Instead, the interplay between processing history and interfacial chain properties can determine whether such systems reach equilibrium or remain trapped in long-lived metastable states. Here we show that compositionally identical PNCs, prepared by selectively preadsorbing either short or long polyethylene glycol chains onto silica nanoparticles, evolve toward fundamentally distinct structural and mechanical states during thermal annealing. While short-chain preadsorbed systems remain kinetically arrested, long-chain preadsorbed systems undergo dramatic interfacial reorganization, as reflected by exponential increases in the lowest-wavevector structure factor and the shear modulus. We reveal unusually high activation barriers (∼82 kJ/mol) for interfacial reorganization with in situ kinetic analysis, consistent with slow chain-exchange dynamics at the polymer–particle interface. Our findings establish that equilibrium states in PNCs are not uniquely determined by chemical composition but instead depend critically on the processing history. We emphasize the concept of interfacial memory–the idea that nanoparticle–polymer interfaces encode their processing history, which in turn governs the accessible structural and functional states of the material.
Source: Macromolecules
Authors: Tae Yeon Kong, Eunjin Choi, So Youn Kim
Institution: Seoul National University
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: G1306107521, G1377831007, G2904307647
OpenAlex ID: W7154498368