Mechanically robust hydrogels could find applications such as biomimetic cell scaffolds, drug delivery agents, and materials for soft robotics, however, many hydrogel matrixes are too brittle or weak for such applications. One efficient approach to improve the mechanical characteristics of their matrices is to make reinforced hydrogels that incorporate inorganic or polymeric fillers such as nanofibers into the hydrogel network matrices. Here, we will report a new class of hydrogels with internal hierarchical reinforcing network from soft dendritic colloids (SDCs). The SDCs are a novel colloidal material invented in our group, which has fibrillar polymer backbone decorated by with corona of branched, self-similar fibers down to the nano-scale. The hydrogel SDCs are fabricated in a scalable process of turbulent ionic precipitation. The SDCs have high excluded volume and van der Waals interactions and readily form percolated 3D networks within a medium, resulting in gelation at low volume fractions. We will first show how soft dendritic colloids are fabricated and how system parameters govern the resulting particle morphology and properties. We will then demonstrate that alginate soft dendritic colloids can be incorporated into molecular alginate hydrogel matrices to form hierarchical networks with mechanical properties resulting from synergistic combination of networks at the molecular and particle-scale. Because the reinforcing network and the hydrogel matrix are composed of the same material, these strengthened hydrogel materials are designated “homocomposites”. We show that alginate homocomposites have remarkable mechanical properties. They are also capable of retaining their structure prior to the molecular crosslinking due to the SDC microgel network, granting the ability both 3D print and inject these biodegradable hydrogel materials into designed patterns and architectures with increased toughness.

Self-reinforced hydrogels with hierarchical homocomposite molecular, nano-, and micro-scale networks

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.