Self-assembled polyelectrolyte-based composite hydrogels with enhanced stretchable and adsorption performances

Abstract

Hydrogels have attracted great attention due to their soft and moist properties, but the preparation of hydrogels with good mechanical properties requires further investigation. In this study, we report on the preparation of polyelectrolyte-based polyion complex (PIC) hydrogels polymerized sequentially via two monomers with cationic and anionic groups. The PIC hydrogel was doped with graphene oxide (GO), carbon nanotubes (CNTs), and layered double hydrotalcites (LDHs) with different weight ratios, respectively. The structures and mechanical properties of the formed composite hydrogels were investigated by SEM, BET, nanoindentation, and tensile tests. The addition of GO, CNTs, and LDHs improved the mechanical properties compared to the original hydrogel, and the GO doped composite hydrogel showed the maximum fracture strain above 800%. We also studied the dye adsorption capacities of the prepared hydrogels for methylene blue (MB) and rhodamine B (RhB), and the doped composite hydrogels showed different adsorption properties compared to the original PIC hydrogel. This work provides new clues in the preparation of composite hydrogel materials with enhanced mechanical properties and wider applications.