Inducing Defects in Colloidal Crystals with Thermosensitive PNIPAm Particles

Abstract

Thermosensitive colloidal PNIPAm particles are employed to induce defect structures into a colloidal crystal. The PNIPAm particle size can be controlled by temperature due to collapse of the polymer network above the lower critical solution temperature (LCST). By embedding these PNIPAm particles into a colloidal crystal formed by non-thermoresponsive particles vacancy-like structures could be induced above the LCST and interstitial structures below the LCST. Our aim is to study the three-dimensional defect diffusion by tracing individual particles and to gain insight into the mechanism involved. Here, we present the observed defect diffusion induced in a mixed system of fluorescently labeled PNIPAm and PNIPAm-AAc particles in which defect diffusion was achieved.