The pigments with high near-infrared (NIR) reflectance hold great promise toward both fundamental types of researches and applications for the realization of comfortable indoor-temperature by mitigating urban heat island effect. However, the facile yet simple method for the NIR reflective pigments with bright color and non-toxic feature remains a huge challenge, limiting their practical application. Herein, we proposed a mild and universal method of solution combustion for constructing the non-toxic and NIR reflective yellow-green pigments of Al-doped Y 3 Fe 5 O 12 . The Y 3 Fe 4 AlO 12 pigment presented a high NIR reflectance of 87.66%, and an outstanding acid/alkali resistance. Moreover, the pigment had an impressive color performance (L* = 78.72, a* = − 4.05, b* = 40.04). Besides, the practical near-infrared reflection performance revealed that the transient surface temperature of the Y 3 Fe 4 AlO 12 pigment was 7.6 °C lower than that of the pigment with similar color on the market. This research supplied high NIR reflecting pigments of Y 3 Fe 5−x Al x O 12 as promising coatings for roofs and exterior walls of buildings, acting as a favorable solution for urban heat island effect.
Urban heat island effects are mainly caused by near infrared region (NIR) thermal radiation (700–2500 nm) produced by sunlight. To reduce accumulation of heat, cooling paintings containing NIR reflective pigments is one possible solution. In this research, 4- tert -butyl phthalocyanines were synthesized through environmentally friendly solvent-free methods. The NIR reflective behaviors could be readily tuned through modification of phthalocyanines structures, and it was found out that the distribution state of the electron in d orbit plays a key role in determining the intensity of NIR reflectance. 4- tert- butyl Cu(II) phthalocyanine showed the highest total solar reflectance (73 %) among all synthesized phthalocyanines, and It exhibited good heat resistance, weathering stability. Eventually, the film prepared by mixing polydimethylsiloxane and 4- tert -butyl Cu(II) phthalocyanine (PDMS- Pc ) showed a temperature difference of 7.5 °C compared to pure polydimethylsiloxane film in the model house study, demonstrating potential applications as cooling coatings. This cooling coating material can reduce the energy consumption caused by cooling equipment such as air conditioners which will achieve energy conservation in the future.
危险品化学品经营许可证（带存储）