The compressibility of soft colloids influences their phase behavior and flow properties, especially in concentrated suspensions. Particle compressibility, which is proportional to the reciprocal of the bulk modulus K, is a key parameter for soft polymer-based particles that can be compressed in crowded environments. Here, microgels with different degrees of crosslinking, i.e. softness, are investigated below and above their volume phase transition temperature VPTT. By combining molecular dynamics simulations with small-angle neutron scattering with contrast variation, a change in the particle bulk moduli of two orders of magnitude is observed. The degree of crosslinking has a significant impact on the bulk modulus of the swollen microgel, while above the VPTT the values of K are almost independent of the crosslinking density. The excellent agreement between experimental results and simulations also highlight that the model microgels posses both the internal architecture and the elastic properties of real polymeric networks. This paves the way to a systematic use of simulations to investigate the behavior of dense microgel suspensions. This article is protected by copyright. All rights reserved.
Keywords: bulk modulus; contrast variation; microgels; molecular dynamics simulations; small‐angle scattering; soft colloids; soft matter.
This article is protected by copyright. All rights reserved.