| Full text | |
| Author(s): |
Hidalgo-Araujo, Ana Carolina
;
Salomao, Rafael
;
Berardi, Umberto
;
Dornelles, Kelen Almeida
Total Authors: 4
|
| Document type: | Journal article |
| Source: | SOLAR ENERGY MATERIALS AND SOLAR CELLS; v. 289, p. 15-pg., 2025-04-21. |
| Abstract | |
This experimental study focuses on developing and characterizing thermochromic roof coatings contributing to energy-efficient building solutions. It addresses two key challenges: the limited durability of organic thermochromic pigments and the lack of research on applying thermochromic materials to opaque surfaces, especially inorganic pigments. Two coatings were developed: whereas the first contained a microencapsulated organic pigment (TC), the second used inorganic vanadium dioxide-based particles (VO2-W). Both were applied to ceramic and fiber cement tiles with a formulation that combined a binder (colloidal silica, SiO2) and titanium dioxide (TiO2) to improve durability. The novelty of the paper was the addition of a TiO2-P25 protective layer that retarded photodegradation and improved the long-term stability of the TC pigment. Coating components were evaluated using differential scanning calorimetry, solar reflectance, scanning electron microscopy, infrared spectroscopy, and X-ray diffraction. Coating performance was assessed regarding solar reflectance, thermal emissivity, and hydrophobicity. The results showed that the TC coating responded dynamically to temperature changes, indicating potential for improving buildings' thermal comfort and energy efficiency. On the other hand, the VO2-W coating showed limited performance in the infrared. In particular, TC coatings with TiO2-P25 exhibited 57 % less degradation below the transition temperature and 37 % less when heated. The main finding of this study demonstrated that TiO2-P25 significantly improved the durability of organic thermochromic coatings, offering a promising strategy to reduce the need for artificial cooling, reduce CO2 emissions, and mitigate the urban heat-island effect. The results also addressed critical gaps in the durability of organic thermochromic pigments and the application of inorganic pigments to opaque surfaces. (AU) | |
| FAPESP's process: | 10/19274-5 - Novel methodology for hydrotalcite (Mg6Al2(OH)16CO3.4H2O) synthesis from aqueous suspensions of magnesium oxide (MgO) and aluminum hydroxide (Al(OH)3) and its application in porous ceramics for high temperature thermal insulation |
| Grantee: | Rafael Salomão |
| Support Opportunities: | Research Grants - Young Investigators Grants |
| FAPESP's process: | 22/03655-7 - Reducing energy losses in industrial processes with high-efficiency thermal insulation of microporous castable calcium silicate produced from elements of biomass: eggshells and rice husk ash |
| Grantee: | Rafael Salomão |
| Support Opportunities: | Program for Research on Bioenergy (BIOEN) - Regular Program Grants |
| FAPESP's process: | 24/00850-9 - Characterization and thermo-energetic simulation of multifunctional tiles |
| Grantee: | Ana Carolina Hidalgo Araujo |
| Support Opportunities: | Scholarships abroad - Research Internship - Doctorate |
| FAPESP's process: | 22/14074-5 - Thermochromic and self-cleaning tiles: an adaptive and resilient roof |
| Grantee: | Ana Carolina Hidalgo Araujo |
| Support Opportunities: | Scholarships in Brazil - Doctorate |
| FAPESP's process: | 24/10060-5 - COATINGS FOR THE BUILDING ENVELOPE AND THE AGING ASSESSMENT OF ABSORPTANCE TO SOLAR RADIATION: proposition of a national method for accelerated aging practice |
| Grantee: | Kelen Almeida Dornelles |
| Support Opportunities: | Regular Research Grants |