Single and Double Microencapsulation of Organic Thermochromic Material

• Published in: International journal of energy research 2024-01, Vol.2024 (1)
• Main Authors: Nagare, Sushant M., Hakami, Abdullatif, Stefanakos, Elias K., Srinivasan, Sesha S.
• Format: Article
• Language: English
• Subjects: Absorbance; Carbon; Cations; Construction; Core-shell structure; Differential scanning calorimetry; Dyes; Electron microscopy; Emulsification; Encapsulation; Energy consumption; Energy storage; Enthalpy; Fatigue tests; Fourier transforms; Glass substrates; Green buildings; Heat; Hydrochloric acid; Infrared spectroscopy; Inorganic materials; Metal concentrations; Metal oxides; Microencapsulation; Micrography; Microstructure; Nanoparticles; Photodegradation; Photomicrographs; Scanning electron microscopy; Silica; Silicon; Silicon dioxide; Spectra; Spectroscopic analysis; Spectrum analysis; Sunlight; Surfactants; Thermal energy; Thermal resistance; Thermography; Thermogravimetric analysis; Titanium; Titanium dioxide; Ultraviolet radiation; Ultraviolet spectroscopy; Urban areas; Urban heat islands; X-ray spectroscopy; Zinc oxides
• ISSN: 0363-907X; 1099-114X
• DOI: 10.1155/2024/6149335

With the increase in temperature, urban areas face issues like urban heat islands. The reduction of green vegetation across urban areas has led to a tremendous rise in temperature. Many studies suggest significant cities are currently experiencing this issue to a greater extent. Many researchers are working on building paints and dyes to reduce the heat intake of the building. Organic thermochromic materials are one such alternative for building dye and stain. The main issue with using organic thermochromic materials is that they quickly degrade under sunlight, which makes them less useful for building paint. To overcome this issue, many organic thermochromic black dye materials (OTCBDM) are encapsulated with inorganic materials such as metal oxide, which block sunlight and reduce the effect of degradation. Encapsulation is achieved via the emulsification method of metal oxide. This paper deals with the single and double microencapsulation methods with different surfactant concentrations, metal oxides, and combinations thereof. Various techniques were used such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) with energy‐dispersive X‐ray spectroscopy technique (EDS), and differential scanning calorimeter (DSC), UV‐Vis spectroscopy, thermogravimetric analysis (TGA), and CIE Lab space analysis to determine the materials’ encapsulation and chromatic nature. The FTIR spectra suggested the absorption peaks for the Ti─OH bond (at 814, 903, and 913 cm −1 ) and Si─OH group (at 1,084 and 1,178 cm −1 ) for the commercial dye encapsulated with TiO 2 and SiO 2 . The Ti─O─Si bonds at 1,054 and 1,145 cm −1 showed for the double encapsulation of SiO 2 and TiO 2 either (i) doped or in (ii) layered structures. From the EDS analysis, we can clearly say that the presence of SiO 2 and TiO 2 indicates the encapsulation of the commercial thermochromic black dye material. The SEM micrographs of the TiO 2 encapsulation of OTCBDM seem more promising and uniform core–shell structure formation with CTAB as a surfactant than the SDBS. Moreover, the SEM microstructure results of double encapsulation using both TiO 2 and SiO 2 suggested thicker coating of particles when compared with single encapsulated counterparts. The cold phase of layered double encapsulation of OTCBDM + SiO 2 /TiO 2 shows a darker color than the doped combination as obtained from the CIE Lab results. This feature suggested that an efficient encapsulation and chromatic transitio