(654f) Functional Hybrids Based on Assembly of 2D Materials and Polymeric Nanoparticles

Taheri Qazvini, N. - Presenter, University of Chicago
Zane, K., University of Chicago
de Pablo, J. J., University of Chicago
Tirrell, M. V., University of Chicago
Schwartz, B., University of Chicago
The increasing demand for systems with multiple functionalities requires developing new hybrid materials containing multiple nanocomponents. Despite this demand, the question of how the interactions in these systems can be engineered to control their bottom-up self-assembly into scalable and stable materials remains essentially unexplored. Here we show that self-assembly via different pathways can integrate graphene oxide, nanosilicates and gelatin nanoparticles into macroscopic hybrid structures with tunable properties and tissue compatibility. Depending on the overall concentration, charge, shape, and aspect ratio of the 2D components, the investigated hybrid systems exhibit distinct rheological behaviors and signatures from a viscoelastic liquid to viscoelastic soft solid and from a gel-like to glass-like dynamics. The structural evolution and the arrested dynamics are explained via the interaction potential among the components. The hybrid soft solids reveal a noticeable shear-induced failure but immediately recover their elasticity upon removal of the shear strain. Complementary single-step stress relaxation experiments provide a comprehensive description of the nonlinear rheological response of these materials. The tunability of the rheological properties, demonstrated by our hybrid system, is valuable for emerging technologies such as 3D printing. Further, we show that upon drying under controlled conditions, these hybrid soft materials can be converted to preformed dense structures, self-standing films, coatings on metallic or glass substrates, and 3D porous scaffolds. The prepared scaffolds are biocompatible and synergistically promote osteogenic differentiation of mesenchymal stem cells.