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Increased energy consumption, driven by climate change and the rise of new industries, has spurred a demand for alternative cooling technologies to replace energy‐intensive systems and mitigate environmental pollution. Radiative cooling, leveraging the optical properties of materials to cool without emitting pollutants or consuming energy, is considered a suitable solution. Among the various form of radiative cooling devices, paint stands out as a practical application for radiative cooling. Hence, a passive daytime radiative cooling (PDRC) paint is developed using a polyurethane binder and zeolitic imidazolate framework (ZIF)‐8. ZIF‐8 is synthesized in an environmentally friendly manner using deionized water as the solvent, resulting in paint with a reflectance of 94.9%, emissivity of 94%, and cooling power of 113 W m−2. Temperature measurements reveal that the paint reduced ambient temperatures by an average of 5.7 °C, reaching up to 8.1 °C during the day. Additionally, with a self‐assembly monolayer coating, the PDRC surface exhibited super‐hydrophobicity and self‐cleaning capabilities. Therefore, the proposed ZIF‐8‐based PDRC paint offers sub‐room temperature cooling potential and is anticipated to reduce energy consumption for cooling, thereby alleviating environmental pollution in various applications, particularly in building exteriors. [ABSTRACT FROM AUTHOR]

Daytime radiative cooling is an eco‐friendly cooling technique that does not consume additional fuel and is a promising technology now being developed using various materials and methods. Existing radiative cooling emitters are typically in the form of multilayered or mixed thin films and photonic structures, which are difficult to apply in industrial fields. Moreover, the complicated processes and materials used increase the cost. Herein, a dual‐modal radiative cooling emitter in the form of a cover sheet developed by electrospinning polyacrylonitrile (PAN) with alumina (Al2O3) and silica (SiO2) nanoparticles is reported; it is an easily accessible and highly practical architecture that can be applied and used in daily life. Additionally, this radiative cooling cover sheet exhibits dual selective‐ and broadband‐like optical properties in the IR region depending on the substrate characteristics for efficient cooling. The cooling power is numerically proven to be 89.51 W m−2, and experimentally, a temperature drop of 9.67 °C could be measured on a daily car model. [ABSTRACT FROM AUTHOR]

Anti-reflection technology is a core technology in the field of optoelectronic devices that is used to increase efficiency by reducing reflectance. In particular, the bio-mimetic moth-eye pattern has the advantage of being independent of wavelength, polarization, and angle of incidence. In this study, we fabricated a 1.1 m wide meter-scale moth-eye film using roll-to-roll printing. A uniform moth-eye pattern with a height of 170 nm was formed, which reduced the average reflectance value by 3.2% and increased the average transmittance value by 3.1%, in a wide wavelength range of 400–700 nm. Additionally, the moth-eye film coated with a self-assembled monolayer (SAM) exhibited a contact angle of 140.3°, almost equal to the superhydrophobic angle of 150°. Furthermore, the contact angle, transmittance, and reflectance of the SAM-coated moth-eye film were maintained after an environmental test, which was conducted for 168 h at 60 °C and 80% humidity. [ABSTRACT FROM AUTHOR]

Daytime radiative cooling serving as a method to pump heat from objects on Earth to cold outer space is an attractive cooling option that does not require any energy input. Among radiative cooler structures, the multilayer‐ or photonic‐structured radiative cooler, composed of inorganic materials, remains one of the most complicated structures to fabricate. In this study, transparent sapphire‐substrate‐based radiative coolers comprising a simple structure and selective emitter‐like optical characteristics are proposed. Utilizing the intrinsic optical properties of the sapphire substrate and adopting additional IR emissive layers, such as those composed of silicon nitride thin film or aluminum oxide nanoparticles, high‐performance radiative coolers can be fabricated with a low mean absorptivity (3–4%) at 0.3–2.5 µm and a high mean emissivity of over 90% at 8–13 µm. Experiments show that the fabricated radiative coolers reach temperature drops of ≈10 °C in the daytime. From the theoretical calculations of radiative cooling performance, the sapphire‐substrate‐based radiative coolers demonstrate a net cooling power as high as 100 Wm−2. [ABSTRACT FROM AUTHOR]

Daytime radiative cooling (DRC) has emerged as a promising method for temperature reduction of surfaces exposed to sunlight, without energy consumption. Despite advancements in DRC design, existing reflector‐based methodologies often lack transparency because of visible reflection, hindering the widespread application of this technology using glass. Efforts to address this challenge have led to the development of transparent radiative cooling (TRC), although efficient cooling during daylight remains challenging because of the dominant solar energy absorption. This paper proposes a novel TRC design comprising a polydimethylsiloxane (PDMS) emitter atop a transparent dual‐reflector structure. An optimized Bragg reflector (OBR) and a 90 µm‐hole‐punctured Ag window screen reflector (WR) are used to reflect band A of the near‐infrared (NIR) spectrum (0.74 < λ < 1.4 µm) and the overall solar spectrum, respectively. During the daytime, the proposed TRC lowers the temperature by 22.1 °C through the transparent dual reflector system, compared to a PDMS‐coated glass. Thus, this approach optimizes the balance between solar reflection and visibility using a dual reflector, offering an optimal solution for applications requiring both cooling and transparency. [ABSTRACT FROM AUTHOR]