Details

Autor(en) / Beteiligte

• Koziol, Martha Franziska
• Nguyen, Phuong Loan
• Gallo, Shannon
• Olsen, Bradley D
• Seiffert, Sebastian

Titel

Hierarchy of relaxation times in supramolecular polymer model networks

Ist Teil von

• Physical chemistry chemical physics : PCCP, 2022-02, Vol.24 (8), p.4859-487

Ort / Verlag

England: Royal Society of Chemistry

Erscheinungsjahr

2022

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Supramolecular polymer gels are an evolving class of soft materials with a vast number of properties that can be tuned to desired applications. Despite continuous advances concerning polymer synthesis, sustainability or adaptability, a consistent understanding of the interplay between structure, dynamics, and diffusion processes within transient networks is lacking. In this study, the hierarchy of several relaxation processes is investigated, starting from a microscopic perspective of a single sticker dissociation event up to the center-of-mass diffusion of a star-shaped polymer building block on different length scales, as well as the resulting macroscopic mechanical response to applied external stress. In addition to that, a second focus is placed on the gel micro-structure that is analyzed by light scattering. Conversion of the dynamic light scattering (DLS) inverse length scale into real space allows for a combination of relaxation times with those obtained by forced Rayleigh scattering (FRS). For these investigations, a model-type metallo-supramolecular network consisting of narrowly dispersed tetra-arm poly(ethylene glycol)-terpyridine macromolecules that are interconnected via complexation with zinc ions is chosen. Assembling the obtained activation energies reveals that all complex dissociation-governed relaxation processes exhibit similar activation energies. A multitude of synergistic experimental techniques are used to investigate the hierarchy of relaxation modes coming along with the formation of a supramolecular polymer network.