Manipulating Toughness and Microstructure in Polyelectrolyte Complex Hydrogels with Competitive Surfactant Micelles
作者：Jiawen Hou, Xiaoliang Wang, Pingchuan Sun,* and Fenfen Wang*
關(guān)鍵字：Polyelectrolyte complex, Toughness, Microstructure, Surfactant Micelles
論文來源：期刊
具體來源：Langmuir 2025, 41, 986?998
發(fā)表時間：2024年
Polyelectrolyte complex (PEC) hydrogels provide a promising
strategy to develop a class of physically cross-linked networks characterized by
exceptional toughness and self-healing properties. However, the precise control
of the microstructure and the enhancement of mechanical properties still pose
challenges in the field of PEC hydrogels. Herein, we propose a strategy to
manipulate the structure of PEC with competitively charged surfactant
micelles, leveraging the spatially confined surface charge and excluded volume
effects to overcome coacervation issues associated with the PEC, thus
achieving a simple one-step preparation of macroscopically uniform and tough
PEC hydrogels. Specifically, polyelectrolyte complex/surfactant micelle (PECSM)
hybrid hydrogels were prepared by one-step copolymerization of chitosan
(CS)/acrylic acid/cetyltrimethylammonium bromide (CTAB) micelles. The content of CTAB micelles was found to continuously
modulate both the structure and the mechanical properties of the resulting PEC-SM hydrogel network. On one hand, reversible
deformation-recovery behavior exhibited by CTAB cavity micelles through hydrophobic interactions efficiently dissipates energy; on
the other hand, competition between CS chains and CTAB micelles for electrostatic binding sites with poly(acrylic acid), along with
excluded volume effects of CTAB micelles, imparts a hierarchical structure upon the PEC-SM hydrogel. Rheology provided detailed
insights into the viscoelastic behaviors of PEC-SM hydrogels at varying CTAB concentrations. The intermolecular interaction and
heterogeneous network structure of physically cross-linked PEC-SM hydrogels with CTAB micelles were elucidated by solid-state
nuclear magnetic resonance (NMR) spectroscopy. On the basis of rheology and NMR results, complemented by other
characterization analyses, the physical illustration of the PEC-SM hybrid hydrogel network structure regulated by competitive
surfactant micelles is presented. This work offers valuable in-depth insight into polyelectrolyte complexation and provides a
foundation for the development of robust PEC hydrogel materials.