X-ray irradiation induces local rearrangement of silica particles in swollen rubber

X-ray photon correlation spectroscopy (XPCS) of swollen rubber containing spherical silica nanoparticles is reported. It is shown that irradiation by intense X-rays leads to the breakdown of cross-links, thereby inducing the local rearrangement of silica nanoparticles. This rearrangement process depends on the cross-link density and is characterized by a compressed exponential relaxation with aging behaviour, which resembles a common feature of complex fluids observed with XPCS.