Traditional passive radiative cooling materials typically exhibit high solar reflectance and mid-infrared emissivity, delivering excellent cooling performance when in direct contact with the surface of an object. However, when the surface of an object is not in contact with radiative cooling materials, the heat emitted by the object first passes through the air with a lower thermal conductivity and is then transferred to radiative cooling materials. Subsequently, the radiative cooling materials transmit the thermal radiation to outer space. This process significantly increases the thermal resistance of the radiative system, thereby impeding the dissipation of heat from the object. To enhance the performance of non-contact radiative cooling, radiative cooling materials must possess high solar reflectance and mid-infrared transmittance. While blocking solar radiation, they should enable the thermal radiation emitted by the object to pass directly through the infrared-transparent material. In this study, we prepared porous poly(4-methyl-pentene) (P-TPX) films with a solar reflectance of 88.6% and an infrared transmittance of 88.11%, aiming to achieve efficient non-contact radiative cooling. Under identical conditions, the P-TPX film, which is transparent to infrared radiation, exhibited superior cooling performance compared to the Poly(vinylidene fluoride-co-hexafluoropropene) porous (P-P(VdF-HFP)) film, which has higher infrared emissivity. The temperature difference between the two films reached up to 4.5 °C, indicating that the infrared-transparent P-TPX film can achieve efficient non-contact radiative cooling.
Plasmonic nanostructures can couple free space light into anultrafine space; therefore,they are employed extensively in the refractive index sensors to minimize the device size or further improve the detection sensitivity. In this work, the optical response of the plasmonic nanotube are investigated comprehensively by using full wave finite element method. With a subwavelength scale, the silver nanotube have prominent scattering peaks in the visible range, which is very suitable for observing through the dark field microscope. The geometric dependence of the scattering spectra and the sensing performance are evaluated carefully. Results show that the scattering peaks are in linear relationship to the circumstance refractive index and a sensitivity of ~337 nm/RIUcan be achieved easily by such a plasmonicnanotube with an optimized size.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.