Microencapsulation of Thermochromic Material by Silicon Oxide Nanoparticles

Abstract

This study is mainly focused on the fabrication of SiO2 as an inorganic shell material encapsulated an organic thermochromic (TC) core material comprises of either the (i) three-component as-synthesized blue dyes [BDTCM@SiO2] or (ii) off-the-shelf (commercial) black dyes [CDTCM@SiO2]. Both the SiO2 encapsulated thermochromic systems have successfully demonstrated the color transition at around 31 °C. For the three-component thermochromic microcapsules, we have used the crystal violet lactone (CVL) as a leuco dye, bisphenol-A (BPA) as a color developer, and 1-tetradecanol (TD) as a solvent. Different ratios of the thermochromic dye and the metal oxide were prepared to examine the effect of the core@shell ratio on the microstructural and thermal properties of the encapsulated microcapsules. The mean particles sizes of the BDTCM@SiO2 are below 100 nm, whereas, the CDTCM@SiO2 samples exhibited the mean particle sizes varied in a range of 100-1000 nm. The endothermic phase transition due to melting and in general, the thermal stabilities of these SiO2 encapsulated TCMs have been explored for the purpose of deploying these systems for thermal energy savings or storage applications.

Effect of surfactant on the TiO 2 microencapsulation of Thermochromic materials

“…The TCM phase change from solid to liquid, when the solvent melts, is responsible for the color change 36,37 . Differential scanning calorimetry (DSC) was utilized to analyze different types of materials, such as the CDTCM encapsulated with TiO 2 using CTAB, SDBS, and HEXA as surfactants.…”

“…The TCM phase change from solid to liquid, when the solvent melts, is responsible for the color change. 36,37 Differential scanning calorimetry (DSC) was utilized to analyze different types of materials, such as the CDTCM encapsulated with TiO 2 using CTAB, SDBS, and HEXA as surfactants. Table 2 shows the peak temperatures and the enthalpy values associated with the phase transition for samples, plain CDTCM and TiO 2 @CDTCM encapsulated using CTAB, SDBS, and HEXA, respectively.…”

Preparation of Temperature-Sensitive Colour-Changing Materials and Their Applications to Clothing Fabrics: Taking a Compound Composed of Crystal Violet Lactone, Bisphenol A, and Octadecanol as an Example

“…The fabric strength test follows the GB/T19976-2005 standard to measure the bursting strength of the fabric using a fabric strength machine [14]. During the testing process, the fabric was first cut into small pieces.…”

In vitro hydrolytic degradation properties of poly(D, L-lactic acid) / poly(L-lactide-co-ε-caprolactone) blend films

“…All of the coating procedures were performed in a Class-10,000 clean room within temperature range of 20~25°C and relative humidity of 40%~50%. Due to the different densities of the solutions prepared with different mixing ratios, the films prepared under the same spraying parameters had slight differences in thickness [7]. The thickness of all films was 85±5 μm.…”