Applications electrochromic windows

Metal-oxide-based electrochromic systems are especially interesting for the development of electrochromic windows because they mostly switch from a transparent state to a dark colored state [38,39]. In addition, their relatively slow response times are acceptable for this kind of application, possibly even preferable from an aesthetic point of view. Again, W03 has seen the most use in the development of actual devices. Several different deposition techniques have been applied. For example, a prototype electrochromic window based on W03 with reasonable dimensions (0.7 X 1 m) has been assembled that reduces light transmission by a factor of 4 in its colored state [28]. 

Many electrochemically dopant-induced structure-property changes in conducting polymers have been described for use in, for example, electrochromic windows and displays, electrochemically controlled chemical separation and delivery systems, redox capacitors, electromechanical actuators, etc.,32. Some of these are apparently close to commercial application. Polypyrrole capacitors are already in conunercial production,27. 

As naturally abundant and low-cost semiconductor, NiO is widely used in electrochromic windows [20], batteries [21], supercapacitors [22], and sensors [23], While all these applications benefit from an interconnected, three-dimensional NiO nanostructure that combines a high specific surface area with a good electric conductivity, the performance enhancement becomes vividly evident as an increased coloration contrast and improved switching behavior when applied in electrochromic devices. NiO nanomaterials recently employed in electrochromic studies include nanocomposites [24], inverse opals [25], macroporous [26] and mesoporous films [27-29],... 

Collomb-Dunand-Sauthier, M.-N., S. Langlois, and E. Genies. 1994. Spectroelectrochemical behaviour of poly(3-octylthiophene) Application to electrochromic windows with polyaniline and iridium oxide. / Appl Electrochem 24 72-77. 

Jelle, B.P. and G. Hagen. 1998. Electrochemical multilayer deposition of polyaniline and Prussian Blue and their application in solid state electrochromic windows. J Appl Electrochem 28 1061-1065. 

Polymer electrolytes are also sought for a variety of other applications such as sensors, electrochromic devices and photoelectrochemical cells. The ambient temperature operation of many of these requires conductivities of the same magnitude as for batteries. The need for high electrolytic conductivity stems from the fact that the rate at which the solid-state devices can be operated, for example, how fast energy from a Li battery can be drained or the colour of an electrochromic window can be switched, depends to a large extent on the mobility of ionic charge carriers, hence... 

K-Conjugated polymers and oligomers are organic materials with many interesting and useful properties [1, 2], Examples of this class of materials include polyacetylene, polythiophene, polypyrrole, poly(phenylenevinylene) and their derivatives. Electronic conductivity, luminescence and nonlinear optical behavior are all observed in these materials and these properties have been exploited in applications such as electroluminescent devices (polymer light-emitting devices or PLEDs), electrostatic coatings, electrochromic windows, chemical sensors and memory devices [3-9]. 

Poly (thiophene)s are of particular interest as electfochromic materials owing to their chemical stability, ease of synthesis and processability. For the most part, current research has been focused on composites, blends and copolymer formations of several conjugated polyheterocyclics, polythiophene and its derivatives, especially PEIX)T. In one example, poly(3,4-ethylenedioxythiophene) (PEDOT)/poly(2-acrylamido-2-methyl-l-propanesulfonate) (PAMPS) composite films were prepared by Sonmez et al. for alternative electrochromic applications [50]. Thin composite films comprised of PEDOT/PAMPS were reported to switch rapidly between oxidized and neufial states, in less than 0.4 s, with an initial optical contrast of 76% at A.max. 615 nm. Nanostructured blends of electrochromic polymers such as polypyrrole and poly(3,4-ethylenedioxythiophene) were developed via self-assembly by Inganas etal. for application as an electrochromic window [26]. Uniir etal. developed a graft-type electrochromic copolymer of polythiophene and polytetrahydrofuran for use in elecfiochromic devices [51]. Two EDOT-based copolymers, poly[(3,4-ethylenedioxythiophene)-aZ/-(2,5-dioctyloxyphenylene)] and poly[(3,4-ethylenedioxythiophene)-aft-(9,9 -dioctylfluorene)] were developed by Aubert et al. as other candidates for electrochromic device development [52],... 

In addition to conventimial applications such as electrocatalysis, electronic devices, solar cells, and electrochromic windows, conducting... 

The potential uses of this type of device are very broad, for exan le electrochromic windows, which control the radiant energy transfer in buildings and cars, inqtroving energy efficiency (1, 3), electrochromic rear-view minor systems in cars, flat panel displays, and smart paint The prospects for these l ds of applications have generated a high demand for new materials wifti inq)roved electrochromic response, thich is reflected in die increasing number of publications on the topic in recent years (4). 

Macfarlane D.R., Sun J., Forsyth M., Bell J.M., Evans L.A., Skryabin I.L. Polymer electrolytes for electrochromic window applications. Solid State Ion. 1996 86-88 959-964 Maheswari S.P., Habib M.A. Electrochromic aspects of phosphotungstic acid. Sol. Energy Mater. Sol. Cells 1988 18 75-82... 

The most restrictive drawback is that the deposition should be carried out on a conducting or a doped semiconducting surface. This is why it is not yet popular for most high-tech electro-optic applications, whereas it is extremely useful for coatings in the automotive industry, for the fabrication of batteries, fuel cells, and electrochromic windows, all of which involve films on conductive supports. Electrophoretic deposition conditions involve the presence of colloidal suspensions, but methods for in situ formation of particulates by faradaic acidification or base formation were amply described as well [44]. Finally, gas evolution (Hj) may be considered a technicality, but it adversely affects the film quality and may pose a safety hazard unless appropriately handled. 

The field of EISA-modified electrodes is one of the most vibrant in contemporary sol-gel electrochemistry, with applications in metal ion sensing [340,341,343], gas sensing [344], lithium intercalation anodes [345], electrochromic windows... 

The permanent coating of electrodes by a layer of an electroactive polymer is an effective strategy for providing it with functionalities very specific to various application fields, including sensors, actuators, batteries, electrochromic windows, light-emitting diodes, and solar cells. 

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