writer：Jiawen Hou, Xiaoliang Wang, Pingchuan Sun,* and Fenfen Wang*
keywords：Polyelectrolyte complex, Toughness, Microstructure, Surfactant Micelles
source：期刊
specific source：Langmuir 2025, 41, 986?998
Issue time：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.