Thermally switchable dispersions of thermochromic Ag2HgI4 nanoparticles

Abstract

Thermochromic Ag(2)HgI(4) nanoparticles 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 Ag(2)HgI(4) nanoparticles 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 Ag(2)HgI(4). Stable dispersions with a reversible temperature-induced colour change from yellow to orange (T(trs) = 25-40 degrees C) were obtained.

Waterborne UV-curable polyurethane acrylate/silica nanocomposites for thermochromic coatings

“…The thermochromic coating was prepared by mixing PUA/SiO 2 binders, photoinitiator 2959, HgI 2 , KI, AgNO 3 and deionized water. The synthesis reaction equations 28 of thermochromic pigments are as follows:…”

Investigation of thermochromic photoluminescent, dielectric and crystal structural properties for an inorganic–organic hybrid solid of [1-hexyl-3-methylimidazolium][PbBr3]

“…4 The thermochromic behavior of a material is based on its absorption spectrum change with temperature. Most of the current thermochromic materials are still traditional inorganic oxides, sulfides or halides, for instance, VO 2 , 1b,5 Ag 2 S, 6 Cu 2 HgI 4 , 7 Ag 2 HgI 4 , 8 as well as nematic mesophase liquid crystals, 9 poly(phenylenevinylene)-based polymers 10 and coordination compounds. [11][12][13][14] In the above-mentioned materials, the thermochromic behavior is generally associated with a structural phase transition.…”

A guest-dependent thermochromic feature in a metal–organic framework and its thin film on different supports

“…The color of a thermochromic material is sensitive to the temperature; such a material has many technological applications in elds such as smart windows which have been used to improve the solar energy efficiency of houses and vehicles and hence for the reduction of energy consumption and CO 2 emission, 1 temperature sensors, 2 color lters 3 and displays. 4 Most of the thermochromic materials, to date, are still traditional inorganic oxides, suldes or halides, for instance, VO 2 , 5 Ag 2 S, 6 Cu 2 HgI 4 , 7 Ag 2 HgI 4 8 as well as nematic mesophase liquid crystals 9 and poly(phenylenevinylene)-based polymers. 10 In this context, the studies on the thermochromic nature of metalorganic framework-based (MOFs) coordination polymers, to the best of our knowledge, have remained sparse, even if some mononuclear transition metal complexes, bis(dimethylammonium)-tetrachloronickelate, 11 bis(diethylammonium)tetrachlorocuprate 12 and Cu(acac) 2 , 13 have been known to show the thermochromic behavior.…”