Sensor chromic

One of the early examples exploiting this chromic transition for sensing was the development of a metal ion sensor by Marsella and Swager [12],... 

Marsella MJ, Swager TM. Designing conducting polymer-based sensors—selective iono-chromic response in crown-ether containing polythiophenes. J Am Chem Soc 1993 115 12214-12215. 

Applications of titania nanotube arrays have been focused up to now on (i) photoelectrochemical and water photolysis properties, (ii) dye-sensitized solar cells, (iii) photocatalysis, (iv) hydrogen sensing, self-cleaning sensors, and biosensors, (v) materials for photo- and/or electro-chromic effects, and (vi) materials for fabrication of Li-batteries and advanced membranes and/or electrodes for fuel cells. A large part of recent developments in these areas have been discussed in recent reviews.We focus here on the use of these materials as catalysts, even though results are still limited, apart from the use as photocatalysts for which more results are available. 

Considering their possible applications in fuel cells, hydrogen sensors, electro-chromic displays, and other industrial devices, there has been an intensive search for proton conducting crystals. In principle, this type of conduction may be achieved in two ways a) by substituting protons for other positively charged mobile structure elements of a particular crystal and b) by growing crystals which contain a sufficient amount of protons as regular structure elements. Diffusional motion (e.g., by a vacancy mechanism) then leads to proton conduction. Both sorts of proton conductors are known [P. Colomban (1992)]. 

Electrochemical applications of polyanilines comprise - electro chromic devices, - electrochemical sensors, and bioelectrochemical devices (- biosensors, - biofuel cells). 

Because in zeolites the silver clusters change their color when in contact with water, it has been suggested that these compounds may be used as water-vapor-sensing materials. Ozin et al. observed the vapor-pressure chromic, cathode-ray chromic, water chromic, photochromic, and thermochromic properties for silver-sodalite, and they proposed that these compounds hold promise for use as sensors.[30] In addition, the silver clusters in zeolites are also sensitive to other molecules, and therefore, they have great potential as chemical-sensing materials. 

Probable applications in various fields like electro chromic displays, electronic devices, modified electrodes, chemical- and bio-sensors etc. [ 133] may be envisaged. Potentially, nanodimensional oxide- (Si02, Mn02 and Zr02) based composites of these polymers have shown promise as optical materials [50]. Conducting polymer-coated low Tg latexes of sub-micron (50-500 nm) dimensions are reported to find use in antistatic and anticorrosion applications [ 113]. In the light of this information it would be of interest to explore the usability of the corresponding MMT-based composites in these directions. 

PAEs are chromic and reveal fascinating spectroscopic properties upon exposure to external stimuli. The UV-vis and fluorescence properties of selected PAEs are treated with regard to inter- and intrachain processes and a model for the spectral changes in PPEs is developed. In the last part, the uses of PAEs as fluorescent sensors and in semiconductor devices are discussed. 

The electrochemical behavior of redox molecules in polymer films and gels has been investigated [4,7,18,23,61-66], but such behavior has usually been studied by using a modified electrode coated with a polymer film or gel in the presence of an outer electrolyte solution. In a few examples, entirely solid-state voltammetry was also achieved, but by using a microelectrode array [65,66] composed of working, counter, and reference electrodes because of the slow ionic or molecular diffusion in the soHd matrices. The apparent diffusion coefficient (Dapp) of a redox substrate in the films or solids coated on an electrode was very small [4,7,18,23,62-66], usually of the order of less than 10 cm s Another example of solid state votammetry is a report on the electrochemistry of Prussian blue in silica sol-gel electrolytes [67], but only Pt gauze working and counter electrodes for a - 1 mm-thick silica solid were used. Moreover, it is well known that solid electrolytes have been used on various sensors, electro chromic devices, etc. [68,69]. However, in spite... 

Based on conducting polymer nanomaterials, various apphcations are reviewed in the final section. These applications include chemical sensor and biosensor, transistor and switch, data storage, supercapacitor, photovoltaic cell, electro chromic device, field emission display, actuator, optically transparent conducting material, surface protection, and substituent for carbon nanomaterials (Fig. 1). Because large amounts of research have been dedicated to this field, it is very difficult to cover whole apphcation fields of conducting polymers. Some comprehensive review articles related to applications of conducting polymers are available [67-73]. 

Polyphosphazenes such as (12.240) form amorphous solvent-free complexes with various salts. These are polymer electrolytes which have potential application in batteries, ion sensors, electro-chromic displays, and so on [83-85]. 

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