New paper on gel mechanics selected as Editor’s Pick

A paper from Prof. Emanuela Del Gado’s group, led by post-doctoral researcher Vinutha H.A. and with co-author Clare Boothe Luce Graduate Fellow Fabiola Diaz Ruiz, was published in the Journal of Chemical Physics and selected as an Editor’s Pick [1]. The paper is an all-women collaboration, with Prof. Xiaoming Mao (University of Michigan) and Prof. Bulbul Chakraborty (Brandeis University), funded by the National Science Foundation Division of Materials Research.

The research focuses on soft particulate gels, which are materials consisting of particulate matter (polymers, colloids, proteins, etc.) aggregated in a solid matrix, sparse and porous, typically embedded in a fluid. Gels of this type are ubiquitous in personal care products and food, in inks for 3D printing technologies and even in construction materials. While the gel structures can be extremely soft because of the overall low solid content, they naturally develop internal stresses during their solidification. The spatial organization of these internal stresses is central to the stress transmission through these materials, and therefore their behavior when used, but it is poorly understood.

Vinutha H.A. used computer simulations and a new theory, originally developed for granular solids like compressed sand, to extract the spatial pattern of local stresses in model particulate gels. The numerical analysis performed by Vinutha H.A. and Fabiola Diaz Ruiz revealed that local stresses are organized into anisotropic structures, similar to force chains found in sand and other granular materials. The new understanding opens new paths to predict the elasticity and mechanical response of soft particulate gels.

[1] Vinutha H. A., Fabiola Diaz Ruiz, Xiaoming Mao, Bulbul Chakraborty and Emanuela Del Gado, “Stress–stress correlations reveal force chains in gels,” Journal of Chemical Physics 158, 114104 (2023), Editor’s Pick. DOI: 10.1063/5.0131473