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Title: Size-Dispersed Calcium Phosphate-Based Paints for Sustainable, Durable Cool Roof Applications
Passive radiative cooling materials are widely recognized as attractive innovations for reducing emissions and expanding life-saving cooling access. Despite immense research attention, the adoption of such technologies is limited largely due to a lack of scalability and cost compatibility with market needs. While paint and coating-based approaches offer a more sensible solution, many demonstrations suffer from issues such as a low solar reflectance performance or a lack of material sustainability due to the use of harmful solvents. In this work, we demonstrate a passive radiative cooling paint which achieves an extremely high solar reflectance value of 98% using a completely water-based formulation. Material sustainability is promoted by incorporating size-dispersed calcium phosphate biomaterials, which offer broadband solar reflectance, as well as a self-crosslinking water-based binder, providing water resistance and durability without introducing harmful materials. Common industry pigments are integrated within the binder for comparison, illustrating the benefit of finely-tuned particle size distributions for broadband solar reflectance, even in low-refractive-index materials such as calcium phosphates. With scalability, outdoor durability, and eco-friendly materials, this demonstrated paint offers a practical passive radiative cooling approach without exacerbating other environmental issues.  more » « less
Award ID(s):
2321446
PAR ID:
10541205
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
MDPI
Date Published:
Journal Name:
Energies
Volume:
17
Issue:
16
ISSN:
1996-1073
Page Range / eLocation ID:
4178
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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