Sensor system dyeing processes

Dyeing-process behaviour with and without sensor system... 

Urea in kidney dialysate can be determined by immobilizing urease (via silylation or with glutaraldehyde as binder) on commercially available acid-base cellulose pads the process has to be modified slightly in order not to alter the dye contained in the pads [57]. The stopped-flow technique assures the required sensitivity for the enzymatic reaction, which takes 30-60 s. Synchronization of the peristaltic pumps PI and P2 in the valveless impulse-response flow injection manifold depicted in Fig. 5.19.B by means of a timer enables kinetic measurements [62]. Following a comprehensive study of the effect of hydrodynamic and (bio)chemical variables, the sensor was optimized for monitoring urea in real biological samples. A similar system was used for the determination of penicillin by penicillinase-catalysed hydrolysis. The enzyme was immobilized on acid-base cellulose strips via bovine serum albumin similarly as in enzyme electrodes [63], even though the above-described procedure would have been equally effective. 

CT and catalysis in a polymer membrane coated on an electrode are important processes to create various sensors and devices for photochemical energy conversion. Among such devices, the apphcation to solar cells and future artificial photosynthetic systems to create energy from simshine is attracting a great deal of attention. In this section, appHcations of CT and catalysis in a polymer membrane coated on an electrode to a dye-sensitized solar cell and an artificial photosynthesis are reviewed. 

In the second type of experiments the polymer is vibrationally excited by the infrared pulse (Fig. 16.1b). The excitation energy is redistributed giving rise to an increased temperature of the pumped volume [5]. The energy equilibration in the polymer system involves intermolecular transfer of energy to the dye molecules which serve as sensors for the equilibration process. The instantaneous temperature is monitored via electronic transitions and the subsequently emitted fluorescence signal of the dispersed dye molecules as discussed above. Information is obtained on the time for complete energy equilibration but not on the individual relaxation steps which can be investigated e. g. by an IR double resonance technique. 

Polysquaraines, also known as wide absorption spectrum squaraines, are currently under development. The optical properties of these systems are ideal for a variety of optical-electronic materials, such as squaraine-based near-infrared dyes, low-band gap polymers, and cation sensors however, these compounds are difficult to solubilize and process [73]. 

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