Molecular Forces Governing Shear and Tensile Failurein Clay-Dye Hybrid Materials.

Hybrid materials based on photoactivemolecules confined into nanostructuredsubstrates are very promising for technological applications. However,little is known about the impact of organic dyes on the mechanicalproperties of the substrate, a key aspect for their practical implementation.In this work, we use atomistic simulation methods to investigate themechanical properties of two hybrid systems consisting on a clay matrix(laponite) loaded with two different cationic dyes (LDS-722 and pyroninY). We applied tensile and shear deformations to the layered hybridmaterials and characterize the key mechanism triggering their failure.It has been observed that the water and dye molecules located in theinterlaminar spaces are those involved in the deformation processes,while the structure of the laponite layers does not change. Furthermore,it has been also found that the incorporation of dye molecules modifiesthe hydrogen-bonding network of water in the interlaminar space, worseningthe mechanical properties of the hybrids with respect to the clay.The information obtained by molecular simulation help us to assessthe mechanical behavior of these materials, and to design materialswith tailored strength. [ABSTRACT FROM AUTHOR]