Thermochromic Fenestration Elements Based on the Dispersion of Functionalized VO 2 Nanocrystals within a Polyvinyl Butyral Laminate.

Autor: Cool NI; Department of Chemistry, Texas A&M University, College Station, Texas 77843-3012, United States.; Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843-3012, United States., Larriuz CA; Department of Chemistry, Texas A&M University, College Station, Texas 77843-3012, United States.; Department of Chemistry, University of Puerto Rico, Cayey, Puerto Rico 00736, United States., James R; Department of Chemistry, Texas A&M University, College Station, Texas 77843-3012, United States., Ayala JR; Department of Chemistry, Texas A&M University, College Station, Texas 77843-3012, United States.; Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843-3012, United States., Anita; Department of Chemistry, Texas A&M University, College Station, Texas 77843-3012, United States.; Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843-3012, United States., Al-Hashimi M; Department of Chemistry, Texas A&M University at Qatar, Doha 23874, Qatar., Banerjee S; Department of Chemistry, Texas A&M University, College Station, Texas 77843-3012, United States.; Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843-3012, United States.
Jazyk: angličtina
Zdroj: ACS engineering Au [ACS Eng Au] 2022 Dec 21; Vol. 2 (6), pp. 477-485. Date of Electronic Publication: 2022 Jul 21.
DOI: 10.1021/acsengineeringau.2c00027
Abstrakt: The energy required to heat, cool, and illuminate buildings continues to increase with growing urbanization, engendering a substantial global carbon footprint for the built environment. Passive modulation of the solar heat gain of buildings through the design of spectrally selective thermochromic fenestration elements holds promise for substantially alleviating energy consumed for climate control and lighting. The binary vanadium(IV) oxide VO 2 manifests a robust metal-insulator transition that brings about a pronounced modulation of its near-infrared transmittance in response to thermal activation. As such, VO 2 nanocrystals are potentially useful as the active elements of transparent thermochromic films and coatings. Practical applications in retrofitting existing buildings requires the design of workflows to embed thermochromic fillers within industrially viable resins. Here, we describe the dispersion of VO 2 nanocrystals within a polyvinyl butyral laminate commonly used in the laminated glass industry as a result of its high optical clarity, toughness, ductility, and strong adhesion to glass. To form high-optical-clarity nanocomposite films, VO 2 nanocrystals are encased in a silica shell and functionalized with 3-methacryloxypropyltrimethoxysilane, enabling excellent dispersion of the nanocrystals in PVB through the formation of siloxane linkages and miscibility of the methacrylate group with the random copolymer. Encapsulation, functionalization, and dispersion of the core-shell VO 2 @SiO 2 nanocrystals mitigates both Mie scattering and light scattering from refractive index discontinuities. The nanocomposite laminates exhibit a 22.3% modulation of NIR transmittance with the functionalizing moiety engendering a 77% increase of visible light transmittance as compared to unfunctionalized core-shell particles. The functionalization scheme and workflow demonstrated, here, illustrates a viable approach for integrating thermochromic functionality within laminated glass used for retrofitting buildings.
Competing Interests: The authors declare no competing financial interest.
(© 2022 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE
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