Passive radiative cooling technologies are highly attractive in pursuing sustainable development. However, current cooling materials are often static, which makes it difficult to cope with the varying needs of all-weather thermal comfort management. Herein, a strategy is designed to obtain flexible thermoplastic polyurethane nanofiber (Es-TPU) membranes via electrospinning, realizing reversible in-situ solvent-free switching between radiative cooling and solar heating through changes in its optical reflectivity by stretching. In its radiative cooling state (0% strain), the Es-TPU membrane shows a high and angular-independent reflectance of 95.6% in the 0.25-2.5 mu m wavelength range and an infrared emissivity of 93.3% in the atmospheric transparency window (8-13 mu m), reaching a temperature drop of 10 degrees C at midday, with a corresponding cooling power of 118.25 W/ m2. The excellent mechanical properties of the Es-TPU membrane allows the continuous adjustment of reflec-tivity by reversibly stretching it, reaching a reflectivity of 61.1% (Delta R = 34.5%) under an elongation strain of 80%, leading to a net temperature increase of 9.5 degrees C above ambient of an absorbing substrate and an equivalent power of 220.34 W m- 2 in this solar heating mode. The strong haze, hydrophobicity and outstanding aging resistance exhibited by this scalable membrane hold promise for achieving uniform illumination with tunable strength and efficient thermal management in practical applications.

Strain-adjustable reflectivity of polyurethane nanofiber membrane for thermal management applications / Li, Xin; Ding, Zhenmin; Emanuele Lio, Giuseppe; Zhao, Jiupeng; Xu, Hongbo; Pattelli, Lorenzo; Pan, Lei; Li, Yao. - In: CHEMICAL ENGINEERING JOURNAL. - ISSN 1385-8947. - 461:(2023), p. 142095. [10.1016/j.cej.2023.142095]

Strain-adjustable reflectivity of polyurethane nanofiber membrane for thermal management applications

Lorenzo Pattelli
;
2023

Abstract

Passive radiative cooling technologies are highly attractive in pursuing sustainable development. However, current cooling materials are often static, which makes it difficult to cope with the varying needs of all-weather thermal comfort management. Herein, a strategy is designed to obtain flexible thermoplastic polyurethane nanofiber (Es-TPU) membranes via electrospinning, realizing reversible in-situ solvent-free switching between radiative cooling and solar heating through changes in its optical reflectivity by stretching. In its radiative cooling state (0% strain), the Es-TPU membrane shows a high and angular-independent reflectance of 95.6% in the 0.25-2.5 mu m wavelength range and an infrared emissivity of 93.3% in the atmospheric transparency window (8-13 mu m), reaching a temperature drop of 10 degrees C at midday, with a corresponding cooling power of 118.25 W/ m2. The excellent mechanical properties of the Es-TPU membrane allows the continuous adjustment of reflec-tivity by reversibly stretching it, reaching a reflectivity of 61.1% (Delta R = 34.5%) under an elongation strain of 80%, leading to a net temperature increase of 9.5 degrees C above ambient of an absorbing substrate and an equivalent power of 220.34 W m- 2 in this solar heating mode. The strong haze, hydrophobicity and outstanding aging resistance exhibited by this scalable membrane hold promise for achieving uniform illumination with tunable strength and efficient thermal management in practical applications.
File in questo prodotto:
File Dimensione Formato  
2302.13043.pdf

embargo fino al 23/02/2025

Descrizione: accepted manuscript and supporting information
Tipologia: accepted manuscript (author’s post-print)
Licenza: Creative Commons
Dimensione 3.34 MB
Formato Adobe PDF
3.34 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
1-s2.0-S1385894723008264-main.pdf

non disponibili

Descrizione: editorial version
Tipologia: final published article (publisher’s version)
Licenza: Non Pubblico - Accesso privato/ristretto
Dimensione 2.8 MB
Formato Adobe PDF
2.8 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11696/76699
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 15
social impact