Effect of surfactant on the TiO2 microencapsulation of Thermochromic materials

Abstract

This work investigates the effect of surfactant on the microencapsulation of thermochromic materials (TCMs) by TiO2. Three types of surfactants, namely Cetrimonium Bromide(CTAB), Sodium Dodecyl Benzene Sulphonate (SDBS), and Hexadecanol (HEXA) are deployed during the microemulsion process for the formation of a TiO2 shell layer on a commercial dyeTCM(CDTCM). These off-the-shelf CDTCMs are primarily Leuco dye particles that exhibit a color change (black to white) behavior at around 33°C. The role of TiO2 shell material encapsulation is to protect the CDTCMs from solar-irradiated photodegradation by absorbing harmful UV radiation. Various analytical characterization methods, such as XRD, FTIR, UV-Vis, DSC, SEM, HRTEM, and EDS were used to evaluate both the plain CDTCM and its TiO2 microencapsulated counterparts in terms of unraveling the structural, microstructural, chemical, and thermal properties. The reversible color change chromic characteristics were quantitatively and qualitatively examined via CIE Lab measurements. The microencapsulated TiO2@CDTCM fabricated in this study shows reversible thermochromic color change behavior and therefore has the potential for applications in energy-savings in building envelops, smart windows, thermal energy storage and textile industries.