# Double-Layer Coating Containing Boron Nitride Powder for Efficient Daytime Radiative Cooling

https://mdr.nims.go.jp/datasets/774f94cc-7f96-48fc-9a21-5972d895cab7

## File

- [radcool_BN_v5a_clean.pdf](https://mdr.nims.go.jp/filesets/f1ece087-2f56-4d6d-8adc-c0217418f07f/download) ([Detail](https://mdr.nims.go.jp/filesets/f1ece087-2f56-4d6d-8adc-c0217418f07f.md))

## Id

774f94cc-7f96-48fc-9a21-5972d895cab7

## Local identifier



## Visibility

open_to_public

## State

published

## Created at

2025-05-03T04:45:48.350167Z

## Updated at

2026-02-21T07:30:20.304099Z

## Published at

2026-02-21T04:38:38.118472Z

## Doi

https://doi.org/10.48505/nims.5463

## First published url

https://doi.org/10.1021/acsaom.4c00519

## Date published

2025-03-28

## Recorded date published

2025-3-28

## Resource type

journal_article

## Manuscript type

accepted_manuscript

## Collection



## Title

- title: Double-Layer Coating Containing Boron Nitride Powder for Efficient Daytime
    Radiative Cooling
  title_type: original
  lang: en

## Description

- description: Daytime radiative cooling outdoors is a passive cooling method that
    emits thermal radiation toward the sky while reflecting sunlight. Many different
    daytime radiative coolers have been developed, and some have been commercialized.
    Coatings offer advantages in ease of application and versatility across different
    surfaces. Typical daytime radiative cooling coatings are mixtures of powders or
    particles in polymer hosts. As these paintings reflect sunlight diffusively, the
    coating thicknesses are sub-millimeters or thicker. Thick coatings result in high
    thermal resistance, which is undesirable for cooling the objects below the coating.
    To address this problem, boron nitride (BN) powder has been used as a material
    with high thermal conductivity to reduce thermal resistance. However, the high
    refractive index of BN in the mid-infrared regions prevents the mid-infrared emissivity
    of BN-containing coatings from achieving values above 0.9 if the concentration
    is high. In the current work, we demonstrate a high average emissivity reaching
    0.93 and solar reflectance of 0.99 by adding a layer containing silica powder
    where the silica layer is instrumental in enhancing the emissivity without deteriorating
    the solar reflectance. The double-layer coatings exhibit subambient outdoor temperatures
    in Japan. Introducing a silica layer for thermal emission on top of a BN-containing
    base layer presents a straightforward method to enhance the daytime radiative
    cooling performance of the BN-containing layer.
  description_type: abstract
  lang: und

## Creator

- name: Satoshi Ishii
  role: author
  orcid: https://orcid.org/0000-0003-0731-8428
  organization: National Institute for Materials Science
- name: Etsuko Shimada
  role: author
- name: Ryugo Hosokawa
  role: author
  orcid: https://orcid.org/0009-0001-7579-4752
  organization: National Institute for Materials Science
- name: Minoru Morioka
  role: author
- name: Motoharu Fukazawa
  role: author
- name: Takashi Kawasaki
  role: author

## Contact agent



## Publisher

organization: American Chemical Society (ACS)

## Managing organization



## Keyword

- subject: Daytime radiative cooling
  schema: not_defined
- subject: Boron nitride
  schema: not_defined
- subject: Thermal radiation
  schema: not_defined
- subject: Double-layer coating
  schema: not_defined

## Rights

- description: This document is the Accepted Manuscript version of a Published Work
    that appeared in final form in ACS Applied Optical Materials, copyright © 2025
    American Chemical Society after peer review and technical editing by the publisher.
    To access the final edited and published work see https://doi.org/10.1021/acsaom.4c00519
  identifier: http://rightsstatements.org/vocab/InC/1.0/

## Other identifier(s)



## Data origin

- data_origin_type: other

## Embargo

start_date: 2025-02-21
end_date: 2026-02-21

## Journal

- title: ACS Applied Optical Materials
  issn: '27719855'
  volume: '3'
  issue: '3'
  start_page: 720
  end_page: 726

## Conference



## Related item



## Funding

- identifier: JPMJPR19I2
  funder_name: Precursory Research for Embryonic Science and Technology
- identifier: 22H01917
  funder_name: Japan Society for the Promotion of Science
- identifier: JPMJFR2139
  funder_name: Fusion Oriented REsearch for disruptive Science and Technology

## Instrument



## Instrument operator



## Instrument managing organization



## Measurement method



## Specimen



## Chemical composition



## Structure for specimen



## Structural feature for specimen



## Specific property for specimen



## Process for specimen treatment



## Computational method



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## Fileset

- id: f1ece087-2f56-4d6d-8adc-c0217418f07f
  filename: radcool_BN_v5a_clean.pdf
  content_type: application/pdf
  size: 838621
  md5: 3721d5cfe038fc07ca92629e88298713

## Thumbnail

fileset_id: f1ece087-2f56-4d6d-8adc-c0217418f07f
filename: radcool_BN_v5a_clean.pdf