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%0 Thesis
%A Buvalaia, Ekaterina
%T From polyelectrolytes towards poly amino acid complexes and protein polymers
%I RWTH Aachen University
%V Dissertation
%C Aachen
%M RWTH-2025-05519
%P 1 Online-Ressource : Illustrationen
%D 2025
%Z Veröffentlicht auf dem Publikationsserver der RWTH Aachen University
%Z Dissertation, RWTH Aachen University, 2025
%X Polyelectrolytes (PEs), polymers with ionizable groups, are fundamental in a wide range of applications, reaching from environmental science to biomedical engineering. This thesis delves into two primary areas of study: first, bridging the knowledge gap between PEs and structurally more complex proteins, particularly focusing on structure and dynamics of PEs, second, examining the formation and behavior of polyelectrolyte complexes (PECs) under diverse environmental conditions. Using polystyrene sulfonate (PSS) as a model PE, its structural and dynamic properties were studied, where dynamics was described as Zimm-like supplemented by internal friction (ZIF). This analysis is aimed to enhance the understanding of hydrodynamic interactions and internal friction within PEs by correlating collective diffusion with local chain dynamics. Dynamic light scattering (DLS), neutron spin-echo (NSE) spectroscopy, pulsed field gradient neutron magnetic resonance (PFG-NMR) spectroscopy and small-angle X-ray scattering (SAXS) were employed to investigate the structure and dynamics of PSS at dilute and semidilute regimes. The second part of the thesis focuses on PECs, composed of oppositely charged poly amino acids (PAAs), examining how environmental factors and PAA variations influence PECs structure. Mixing charged PAAs results in high-density droplet phases and dense hexagonal lattices of parallel α-helices, affected by PAA properties like molecular weight, concentration and pH. These mixtures are promising for applications in drug delivery and tissue engineering, requiring an understanding of their phase transitions in response to temperature, pH and ionic strength. The study also explores how magnetic fields and shear forces impact PEC formation and stability, revealing a range of structures from crystalline α-helices to amorphous phases based on salt concentrations. Through these investigations, this thesis aims to shed light on the complex behaviors of PEs and PECs, contributing to a deeper understanding of their roles in diverse applications and biological processes.
%F PUB:(DE-HGF)11
%9 Dissertation / PhD Thesis
%R 10.18154/RWTH-2025-05519
%U https://publications.rwth-aachen.de/record/1013448