• Fruhner, Lisa Sarah
• Richtering, Walter
• Houston, Judith
• Allgaier, Jürgen
• Schweins, Ralf
• Fernandez-Nieves, Alberto
• Petrunin, Alexander V.
• González, Javier Rojo
• De La Cotte, Alexis
• Scotti, Andrea
• Gasser, Urs

Abstract

<jats:p>The bulk modulus,<jats:italic>K</jats:italic>, quantifies the elastic response of an object to an isotropic compression. For soft compressible colloids, knowing<jats:italic>K</jats:italic>is essential to accurately predict the suspension response to crowding. Most colloids have complex architectures characterized by different softness, which additionally depends on compression. Here, we determine the different values of<jats:italic>K</jats:italic>for the various morphological parts of individual nanogels and probe the changes of<jats:italic>K</jats:italic>with compression. Our method uses a partially deuterated polymer, which exerts the required isotropic stress, and small-angle neutron scattering with contrast matching to determine the form factor of the particles without any scattering contribution from the polymer. We show a clear difference in softness, compressibility, and evolution of<jats:italic>K</jats:italic>between the shell of the nanogel and the rest of the particle, depending on the amount of cross-linker used in their synthesis.</jats:p>

Topics

• impedance spectroscopy
• polymer
• isotropic
• small-angle neutron scattering
• bulk modulus