Preparation of cool composite pigment by the layer-by-layer assembling of phthalocyanine green on the surface of rutile TiO2
Abstract
Purpose
This study aims to fabricate a cool phthalocyanine green/TiO2 composite pigment (PGT) with high near-infrared (NIR) reflectance, good color performance and good heat-shielding performance under sunlight and infrared irradiation.
Design/methodology/approach
With the help of anionic and cationic polyelectrolytes, the PGT composite pigment was prepared using a layer-by-layer assembly method under wet ball milling. Based on the light reflectance properties and color performance tested by ultraviolet-visible-NIR spectrophotometer and colorimeter, the preparation conditions were optimized and the properties of PGT pigment with different assembly layers (PGT-1, PGT-3, PGT-5 and PGT-7) were compared. In addition, their heat-shielding performance was evaluated and compared by temperature rise value for their coating under sunlight and infrared irradiation.
Findings
The PGT pigment had a core/shell structure, and the PG thickness increased with the self-assembly layers, which made the PGT-3 and PGT-7 pigment show higher color purity and saturation than PGT-1 pigment. In addition, the PGT-3 and PGT-7 pigment showed 11%–16% lower light reflectance in the visible region. However, their light reflectance in the NIR region was similar. Under infrared irradiation the PGT-5 and PGT-7 pigment coating showed 1.1°C–3.4°C and 1.3°C–4.7°C lower temperature rise value than PGT-1 pigment coating and physical mixture pigment coating, respectively. And under sunlight the PGT-3 pigment coating showed 1.5–2.6°C lower temperature rise value than the physical mixture pigment coating.
Originality/value
The layer-by-layer assembling makes the core/shell PGT composite pigment possess low visible light reflectance, high NIR reflectance and good heat-shielding performance.
Keywords
Acknowledgements
This work was financially supported by National Natural Science Foundation of China [grant numbers 51703155].
Conflict of interest: The authors declare no competing financial interest.
Ethics statement: This article is original, and we have conducted with the highest standards of rigors and integrity. This work has not been submitted elsewhere and is not under consideration for publication elsewhere, and it does not include libelous, defamatory or unlawful statements. Authorship has been agreed prior to submission and no one has been “gifted” authorship or denied credit as an author (ghost authorship).
Citation
Cao, L., Ren, S., Zhou, Z., Fei, X. and Huang, C. (2023), "Preparation of cool composite pigment by the layer-by-layer assembling of phthalocyanine green on the surface of rutile TiO2", Pigment & Resin Technology, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/PRT-03-2023-0027
Publisher
:Emerald Publishing Limited
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