Thermally switchable dispersions of thermochromic Ag2HgI4nanoparticles

Abstract

Thermochromic Ag₂HgI₄nanoparticles were prepared by rapid precipitation from aqueous solution. Stable colloids were formed by coating the particles with four different polymers, respectively. The four resulting systems of functionalised Ag₂HgI₄nanoparticles were characterised with respect to their polymer content (elemental analysis), particle size (dynamic light scattering, scanning electron microscopy), optical properties in dispersion (UV spectroscopy), crystallinity (X-ray powder diffraction), and thermochromic transition temperature (differential scanning calorimetry) and also compared to the unfunctionalised bulk phase Ag₂HgI₄. Stable dispersions with a reversible temperature-induced colour change from yellow to orange (T_trs = 25–40 °C) were obtained.