New Publication from Prof. Del Gado

Graph on left, with steeper slope demonstrating attractive interactions at a lower nanofiller volume. Images on right showing shaded gray region around nanofiller representing effective filler and how stress coupling extends through the network. — Image from the research demonstrating the key nature of attractive interactions, along with the effective filler and effect on stress coupling through the matrix.

ISM Director Emanuela Del Gado has put forth a new publication in collaboration with researchers from the ISM and MIT. “Local Mechanism Governs Global Reinforcement of Nanofiller-Hydrogel Composites” was recently published in ACS Nano. Simulations for the research were done by Minaspi Bantawa during his PhD at Georgetown and by Brian Damerau when he was an undergraduate student in the Physics Department. The research aims to discover general mechanisms for reinforcing hydrogels through the addition of inorganic nanofillers, to make materials with advanced mechanical performance and functionalization. They found enhanced mechanical strength could be realized with a low volume fraction of nanofillers. Using 3-D numerical simulations, it was demonstrated that the attractions between nanofillers and hydrogels were essential for reaching a strong reinforcement, as they lead to the local densification of the gel matrix around nanofillers. The effective filler of nanofiller and surrounding densified region then percolates through the matrix, enhancing long-range stress correlations and constraining gel displacement. Understanding this mechanism can help material design strategies moving forward.