From single-chain nano-particles to all-polymer nano-composites

Resumen del trabajo presentado al APS March Meeting, celebrado de forma virtual del 13 al 19 de marzo de 2021.Single-Chain Nano-Particles (SCNPs) obtainedby intra-molecular cross-linking of linear macromolecules (precursors) are emerging soft nano-objects showing unique and remarkablephysicochemical, rheological, and sensing properties as a result of their locally collapsed structure and ultrasmall size. During last years, we havestudied the properties of systems based on SCNPs, including dilute and crowded solutions, bulks and all-polymer nano-composites with SCNPs asfillers (see, e. g.). Diverse techniques have been combined, including small angle scattering, quasielastic neutron scattering and coarse-gainedmolecular dynamics simulations. Here we present the results on the properties of SCNPs in solution and how they develop upon crowding their environment, with the all-polymer nano-composite as limit. In solution, SCNPs obtained through standard synthesis routes adopt sparsemorphologies. Crowding induces compaction of the SCNPs and in the limit case of the nano-composite, the observed conformation of the SCNPresembles that of a crumpled globule. Furthermore, the impact of the presence of SCNPs on the dynamics of an entangled polymer matrix isaddressed. In the dynamically asymmetric system investigated, we observe a slowing down of the Rouse-like dynamics as well as a pronouncedincrease of the explored volume of the (faster) matrix linear chains. The latter effect is attributed to the particular topology (internalcompartmentation) of the slow SCNP filler component.Peer reviewe