Infrared Regulating Smart Window Based on Organic Materials

Abstract

(IR), here defined as light with wavelengths between 700 nm and 2500 nm, accounts for around 50% of the total energy emitted by the sun reaching Earth (Figure 1b), [3,4] and this light produces interior heating but is invisible to the unaided eye.The absorption of sunlight by building materials and passage of IR through transparent surfaces such as windows is responsible for much of the interior overheating of office rooms, automobile interiors, greenhouses, and other similar spaces. The use of artificial cooling and heating systems will only increase with the continued influence of global climate change, with energy used for cooling systems surpassing energy used for heating around the year 2070, and a 40 fold increase in air cooling energy use is expected by 2100. [5] By controlling the influx of radiant heat transfer, calculations show that more than 50% of the energy used in lighting, heating and cooling could be saved by deploying better control systems over only 18% of available window stock. [6] In areas with human inhabitants employing windows, more aspects must be considered than simply reducing the use of energy in the room: any switchable window used in, for example, a commercial office space has several other requirements that must be met before it may be installed. Among these requirement are reasonably fast switching speeds [7] (although for IR control, relatively longer times compared to visible light switching should be acceptable), good optical transparency with minimum haze, an acceptable device lifetime, [8] and functionality over a range of exterior temperatures. Controlling the excess of solar energy without compromising the visible transparency of the window is an important consideration for human health: maintaining inside/outside contact and daylighting are vital in retaining well-being and productivity, as well as providing economic and aesthetic gain by reducing the need for artificial lighting systems. [9,10] These are challenging goals for a window to realize.A number of materials have been developed over the past few decades to maintain indoor temperatures. Many of these focus on the opaque structural building elements like walls and roofing. [10][11][12][13] Other solutions target the transparent window, employing external mechanical shutters and blinds, [14] phase change materials (PCMs), [15] thermochromic materials, [16] aerogels, [17] trapped gas in fluid membranes, [18] and even phononic materials, [19] among other options. Indeed, controlling heat passage through the window in response to changing climate conditions is a great challenge; ideally, one would accomplish Windows are vital elements in the built environment that have a large impact on the energy consumption in indoor spaces, affecting heating and cooling and artificial lighting requirements. Moreover, they play an important role in sustaining human health and well-being. In this review, we discuss the next generation of smart windows based on organic materials which can change their properties by reflecting or trans...

Simplified All‐Solid‐State WO3 Based Electrochromic Devices on Single Substrate: Toward Large Area, Low Voltage, High Contrast, and Fast Switching Dynamics

“…[1][2][3][4][5] They are recognized as a suitable "green" nanotechnology, because do not impede visibility as other conventional blinding systems, providing, at the same time, glare control, thermal, and visual comfort management. Electrochromic (EC) smart windows, or dynamic tintable glazings, belong to the promising category of products changing their light transmittance in response to external stimuli, like electric field or sunlight irradiance.…”

Graphene Oxide with Controlled Content of Oxygen Groups as a Filler for Polymer Composites Used for Infrared Radiation Shielding

“…To save the energy NIR shielding materials can be used as coatings in buildings and cars to reduce the heat transmission through their outer surfaces. These coatings can be divided into inorganic materials (such as heat-reflective glasses) [1,3,6,7] and polymer composites with inorganic fillers (such as indium tin oxide-ITO, antimony tin oxide-ATO, lanthanum hexaboride-LaB 6 , tungsten oxide-WO 3 nanoparticles) [4,[8][9][10][11]. The fillers should possess high absorption or high reflectance of infrared radiation.…”

The Halogen Bond: An Emerging Supramolecular Tool in the Design of Functional Mesomorphic Materials

“…LCs have been extensively applied in flat panel LC displays (LCDs) as the active switching components. Recently, their potential in numerous beyond display applications have been demonstrated and intense research and development activities in this direction is actively pursued to capitalize on the unique attributes of LC materials . Apart from technological applications, LCs provide greater and deeper insight into the fundamental understanding of self‐assembly and self‐organization of matter at different hierarchical levels .…”

“…Recently,t heir potentiali nn umerous beyond display applica-tions have been demonstrated and intense research and development activities in this direction is actively pursued to capitalize on the unique attributes of LC materials. [8][9][10][11][12][13][14][15][16][17] Apart from technological applications, LCs provideg reater and deeper insight into the fundamental understanding of self-assembly and self-organization of matter at different hierarchical levels. [18][19][20][21][22][23][24][25][26][27][28] Extreme sensitivity of LCs to different external stimuli of small magnitude qualifies them as functionals timuli-responsive soft materials.…”