Researchers from the University of Science and Technology of China (USTC), has put forth an innovative approach for creating intelligent windows that effectively regulate solar radiation and manage heat in buildings. Their findings have been published in the esteemed journal Nature Communications.
The installation of intelligent windows that can block solar radiation and control indoor temperatures is crucial for constructing energy-efficient buildings. While existing smart windows are capable of regulating solar radiation by transitioning between transparent and opaque states, this often compromises the transmission of visible light, thereby impacting indoor illumination. Moreover, these smart windows face challenges in dynamically and selectively modulating solar radiation in response to complex weather changes and individual preferences.
The research team devised a novel strategy based on the unique optical properties of one-dimensional nanomaterials. They synthesized a mixture of gold nanorods with varying aspect ratios, which selectively absorb near-infrared light within a specific wavelength range while preserving the transmission of visible light. Consequently, the room maintains adequate illumination. By co-assembling these multi-sized gold nanorods with electrochromic tungsten bronze nanowires (W18O49) and conductive silver nanowires, the researchers formed an organized mesh structure. The application of an external power supply significantly alters the appearance of the smart windows, further enhancing their ability to block solar radiation.
Employing the same interfacial co-assembly approach, the team also developed thermochromic smart windows (WRT) with a broad response range. These windows were created through the co-assembly of tungsten-doped vanadium dioxide (W-VO2) nanowires with varying levels of W doping. This expands the range of temperatures to which the windows respond, allowing the number of W-VO2 nanowires in the thermochromic state to vary with the ambient temperature. As a result, the color change of the smart windows can be dynamically modulated.
These smart windows can selectively block solar radiation and dynamically adjust the room temperature based on applied voltage or ambient temperature. They contribute to significant energy savings, particularly during hotter months.
The research represents a significant advancement in enhancing the optical properties of windows by manipulating the composition and structure of multiple materials. It enables the rapid and large-scale production of smart windows capable of modulating solar spectrum, offering new possibilities for designing, developing, and implementing electrochromic and thermochromic smart windows.
Source: University of Science and Technology of China