Transparent nanocellulose metamaterial enables controlled optical diffusion and radiative coolingShow others and affiliations
2020 (English)In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 8, no 34, p. 11687-11694Article in journal (Refereed) Published
Abstract [en]
Materials that provide independent control of infrared thermal radiation and haze in the visible could benefit many areas and applications, including clothing, packaging and photovoltaics. Here, we study this possibility for a metamaterial composite paper based on cellulose nanofibrils (CNF) and silicon dioxide (SiO2) microparticles with infrared (IR) Fröhlich phonon resonances. This CNF-SiO2composite shows outstanding transparency in the visible wavelength range, with the option of controlling light diffusion and haze from almost zero to 90% by varying the SiO2microparticle concentration. We further show that the transparent metamaterial paper could maintain high thermal emissivity in the atmospheric IR window, as attributed to strong IR absorption of both the nanocellulose and the resonant SiO2microparticles. The high IR emissivity and low visible absorption make the paper suitable for passive radiative cooling and we demonstrate cooling of the paper to around 3 °C below ambient air temperature by exposing it to the sky.
Place, publisher, year, edition, pages
Royal Society of Chemistry , 2020. Vol. 8, no 34, p. 11687-11694
Keywords [en]
Cellulose, Cellulose nanocrystals, Electromagnetic wave emission, Metamaterials, Nanocellulose, Radiative Cooling, Silica, Silicon oxides, Ambient air temperature, Cellulose nanofibrils, Independent control, Light diffusion, Micro-particles, Optical diffusion, Phonon resonance, Visible-wavelength range, Absorption cooling, Absorption, Cooling, Diffusion, Emissivity, Haze, Paper
National Category
Natural Sciences
Identifiers
URN: urn:nbn:se:ri:diva-48885DOI: 10.1039/d0tc01226bScopus ID: 2-s2.0-85090590147OAI: oai:DiVA.org:ri-48885DiVA, id: diva2:1469762
Note
Funding details: Wallenberg Wood Science Center, WWSC, 2009 00971; Funding details: Stiftelsen för Strategisk Forskning, SSF; Funding details: Linköpings Universitet, LiU; Funding details: Knut och Alice Wallenbergs Stiftelse; Funding text 1: The authors acknowledge financial support from the Knut and Allice Wallenberg Foundation via a Wallenberg Scholarship; the Knut and Alice Wallenberg foundation, Linköping University and industry through the Wallenberg Wood Science Center; the Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linköping University (Faculty Grant SFO-Mat-LiU No. 2009 00971), the Swedish Foundation for Strategic Research and the Swedish Armed Forces Research and Technology programme. The authors also thank Meysam Karami Rad for help with constructing the temperature and cooling power measurement setup.
2020-09-222020-09-222025-09-23Bibliographically approved