Covalent Ferrohydrogels Based on Elongated Particulate Cross-Linkers

The incorporation of surface-functionalized spindle-like hematite nanoparticles as particulate cross-linkers in poly(acrylamide) hydrogel matrices delivers ferrogels with a covalent type of particlematrix interaction. By systematic investigation of the stability and the internal architecture of the resulting gels, the regime of resilient gels is identified. The swelling properties and the rheological behavior are in accordance with a network structure based on particle nodes interlinked by long polymer segments and a significant fraction of loops.