Subscriber access provided by University of Florida | Smathers Libraries
Article
Hybrid Nanocomposite Films Comprising Dispersed VO2 Nanocrystals: A Scalable Aqueous-Phase Route to Thermochromic Fenestration Nathan Fleer, Kate Pelcher, Jian Zou, Kelly Nieto, Lacey Douglas, Diane Sellers, and Sarbajit Banerjee ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.7b09779 • Publication Date (Web): 17 Oct 2017 Downloaded from http://pubs.acs.org on October 19, 2017
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
ACS Applied Materials & Interfaces is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 48
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
ACS Applied Materials & Interfaces
Hybrid Nanocomposite Films Comprising Dispersed VO2 Nanocrystals: A Scalable Aqueous-Phase Route to Thermochromic Fenestration Nathan A. Fleer,a,b Kate E. Pelcher,a,b Jian Zou,a,b Kelly Nieto,a,b Lacey D. Douglas,a,b Diane G. Sellers,a,b* and Sarbajit Banerjee*a,b a
Department of Chemistry, Texas A&M University, College Station, Texas 77842-3012, United
States b
Department of Materials Science and Engineering, Texas A&M University, College Station,
Texas, 77843-3003, United States Corresponding authors E-mail:
[email protected];
[email protected] Keywords: fenestration, nanocrystals, optical coatings, smart glass, smart windows, sustainable nanotechnology, vanadium dioxide
Abstract: Buildings consume an inordinate amount of energy, accounting for 30—40% of worldwide energy consumption. A major portion of solar radiation is transmitted directly to building interiors through windows, skylights, and glazed doors where the resulting solar heat gain necessitates increased use of air conditioning. Current technologies aimed at addressing this problem suffer from major drawbacks, including a reduction in the transmission of visible light, thereby resulting in increased use of artificial lighting. Since currently used coatings are 1 ACS Paragon Plus Environment
ACS Applied Materials & Interfaces
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
temperature-invariant in terms of their solar heat gain modulation, they are unable to offset coldweather heating costs that would otherwise have resulted from solar heat gain. There is considerable interest in the development of plastic fenestration elements that can dynamically modulate solar heat gain based on the external climate and are retrofittable onto existing structures. The metal—insulator transition of VO2 is accompanied by a pronounced modulation of near-infrared transmittance as a function of temperature and can potentially be harnessed for this purpose. Here, we demonstrate that a nanocomposite thin film embedded with well dispersed sub-100 nm diameter VO2 nanocrystals exhibits a combination of high visible light transmittance, effective near-infrared suppression, and onset of NIR modulation at wavelengths 10 kg, the maximum limit tested under the specified method, further demonstrating the excellent adherence of the coatings to glass. Conclusions: In summary, fenestration units that are able to adapt to changes in ambient temperature have the potential to bring about considerable energy savings in both residential and industrial buildings by dynamically modulating solar heat gain in response to the external temperature without requiring human intervention. VO2 exhibits a reversible insulator to metal transition that is accompanied by a massive and dynamically switchable suppression of NIR transmittance and reflectance as a function of temperature. This phase transition can be utilized to limit NIR solar heat gain at high ambient temperatures, while allowing for use of solar heat gain to warm interiors at low ambient temperatures. In this work, we demonstrate that nanocomposite thin films embedded with well dispersed
