Infrared dielectric function of polydimethylsiloxane and selective emission behavior

Srinivasan, Arvind; Czapla, Braden; Mayo, Jeff; Narayanaswamy, Arvind

doi:10.1063/1.4961051

Cited by 76 publications

(44 citation statements)

References 32 publications

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“…PDMS is a promising inexpensive material for daytime radiative cooling due to its transparency in visible regime and strong thermal emissivity in the mid-infrared regime. 39 Here we propose a simple planar PDMS/metal (Al or Ag) film structure to realize an inexpensive thermal emitter for radiative cooling, as illustrated in Fig. 1A.…”

Section: Designing the Planar Pdms Coated Metal Thermal Emittermentioning

confidence: 99%

A polydimethylsiloxane-coated metal structure for all-day radiative cooling

et al. 2019

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Radiative cooling is a passive cooling strategy with zero consumption of electricity, and it can be used to radiate heat from buildings to reduce air conditioning requirements. Although this technology can work well during optimal atmospheric conditions at nighttime, it is essential to achieve efficient cooling during daytime when peak cooling demand actually occurs. In this article, we report an inexpensive planar polydimethylsiloxane (PDMS)/metal thermal emitter, i.e., a thin film structure, which was fabricated using a fast solution coating process that is scalable for large area manufacturing. By performing tests under different environmental conditions, temperature reductions of 9.5 °C and 11.0 °C were demonstrated in the laboratory and outdoor environment, respectively, with an average cooling power of ~120 W/m 2 for the thin film thermal emitter. In addition, a spectral-selective structure was designed and implemented to suppress the solar input and control the divergence of the thermal emission beam. This enhanced the directionality of the thermal emissions, so the emitter's cooling performance was less dependent on the surrounding environment. Outdoor experiments were performed in Buffalo NY realizing continuous allday cooling of 2~9 °C on a typical clear sunny day at Northern United States latitudes. This practical strategy that cools without electricity input could have a significant impact on global energy consumption.

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Section: Designing the Planar Pdms Coated Metal Thermal Emittermentioning

confidence: 99%

A polydimethylsiloxane-coated metal structure for all-day radiative cooling

et al. 2019

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“…It was attributed to the hierarchical porous structure leading to a gradual refractive index transition from the polymer matrix to air cavities, [28] as well as the strong inherent absorption performance of PDMS in the wavelengths localized in LWIR window ( Figure S14, Supporting Information). [35] Because the water droplets in the emulsion were quite stable, the cavity distribution could be easily controlled by simply mixing the emulsion for different durations, allowing us to prepare samples with hierarchical cavity structure to optimize reflection performance (Figure 3a). In addition, the reflection of SPDMS film increases when the film thickness was increased from 300 to 500 µm but not from 500 to 600 µm ( Figure S15, Supporting Information).…”

Section: Doi: 101002/adma202000870mentioning

confidence: 99%

Switchable Cavitation in Silicone Coatings for Energy‐Saving Cooling and Heating

et al. 2020

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Space cooling and heating currently result in huge amounts of energy consumption and various environmental problems. Herein, a switching strategy is described for efficient energy‐saving cooling and heating based on the dynamic cavitation of silicone coatings that can be reversibly and continuously tuned from a highly porous state to a transparent solid. In the porous state, the coatings can achieve efficient solar reflection (93%) and long‐wave infrared emission (94%) to induce a subambient temperature drop of about 5 °C in hot weather (≈35 °C). In the transparent solid state, the coatings allow active sunlight permeation (95%) to induce solar heating to raise the ambient temperature from 10 to 28 °C in cold weather. The coatings are made from commercially available, cheap materials via a facile, environmentally friendly method, and are durable, reversible, and patternable. They can be applied immediately to various existed objects including rigid substrates.

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“…They showed that PDMS can act as a viable material for passive radiative cooling engineering applications. The measurement setup is shown in Figure 7 b [ 48 ]. Lee et al conducted the analysis of high temperature absorber with a structure of a 2D nickel grating atop a thin SiO

film and a nickel substrate, as shown in Figure 7 c, they determined the size of the 2D grating with the Taguchi method optimizing the spectral absorptance in both S and P polarizations [ 49 ].…”

Section: Diverse Structures Of Metamaterialsmentioning

confidence: 99%

A Review of Tunable Wavelength Selectivity of Metamaterials in Near-Field and Far-Field Radiative Thermal Transport

et al. 2018

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Radiative thermal transport of metamaterials has begun to play a significant role in thermal science and has great engineering applications. When the key features of structures become comparable to the thermal wavelength at a particular temperature, a narrowband or wideband of wavelengths can be created or shifted in both the emission and reflection spectrum of nanoscale metamaterials. Due to the near-field effect, the phenomena of radiative wavelength selectivity become significant. These effects show strong promise for applications in thermophotovoltaic energy harvesting, nanoscale biosensing, and increased energy efficiency through radiative cooling in the near future. This review paper summarizes the recent progress and outlook of both near-field and far-field radiative heat transfer, different design structures of metamaterials, applications of unique thermal and optical properties, and focuses especially on exploration of the tunable radiative wavelength selectivity of nano-metamaterials.

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Infrared dielectric function of polydimethylsiloxane and selective emission behavior

Cited by 76 publications

References 32 publications

A polydimethylsiloxane-coated metal structure for all-day radiative cooling

A polydimethylsiloxane-coated metal structure for all-day radiative cooling

Switchable Cavitation in Silicone Coatings for Energy‐Saving Cooling and Heating

A Review of Tunable Wavelength Selectivity of Metamaterials in Near-Field and Far-Field Radiative Thermal Transport

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