INS2-0392
Structural Evolution and Rheological Behavior of Catechol-Modified Hydrogels
Topic
S2. High-End Characterization/Polymer Physics/Properties
When and Where
Sep 29, 2026
11:15 - 11:40
Room 103
Session Chairs
Moon Jeong PARK
Presenter(s)
Daewon Sohn (Hanyang University)
Co-Author(s)
Abstract
Inspired by metal-catechol interactions found in biological systems, dynamic and tunable properties have been incorporated into a variety of polymer hydrogels. In this study, hyaluronic acid (HA)-based hydrogels were developed by controlling the gelation kinetics of Fe(III) ions and catechol-functionalized polymers. The dual roles of Fe(III) in catechol-modified HA (HA-CA)-coordination with catechol groups and Fe(III)-induced catechol oxidation followed by covalent coupling-were exploited to generate distinct gelation mechanisms. In addition, tetra-poly(ethylene glycol) terminated with catechol groups (4-PCA) was crosslinked through Fe(III)-mediated coordination bonds. Depending on pH, catechol-Fe(III) interactions formed either bis- or tris-complexes, resulting in different network architectures. The structures and properties of 4-PCA hydrogels were investigated as functions of pH and the catechol-to-Fe(III) molar ratio. Coordination states were characterized by UV-visible and Raman spectroscopy. Correlation lengths (ξ) in semidilute polymer solutions and hydrogel networks were determined using dynamic light scattering, small angle X-ray scattering (SAXS), and small angle neutron scattering (SANS). Hydrogels dominated by bis-complex crosslinks exhibited ξ values comparable to the dimensions of individual polymer chains, indicating relatively homogeneous networks. In contrast, hydrogels containing predominantly tris-complex crosslinks showed larger ξ values, suggesting heterogeneous structures with partially crosslinked domains. The rheological behavior was analyzed in relation to the spatial, temporal, and thermal hierarchy of the hydrogel networks. These results provide insight into the structure-property relationships of metal-catechol-crosslinked hydrogels and offer guidelines for designing mechanically tunable biomimetic materials.
