Page 239 - Polymer-based Nanocomposites for Energy and Environmental Applications
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Polymer nanocomposites for sensor devices                         211

























           Fig. 7.4 Schematic preparation of the polythiophene-coated gold nanoparticles from
           3-(10-bromodecyl)thiophene (BDT) via thiol 3-(10-mercaptodecyl)thiophene (MDT).
           Reproduced from Rajesh TA, Kumar D. Recent progress in the development of nano-structured
           conducting polymers/nanocomposites for sensor applications. Sens Actuators B 2009;
           136:275–86, with permission from Elsevier Science.

           7.5.1  Polyurathene based nanocomposites

           Electrically conductive CB, insulating needle form of nanoclay, sepiolite, with con-
           junction of multiwalled CNTs (MWCNTs), is used for the development of thermo-
           plastic polyurethane and MWCNT-based materials. The prepared nanocomposites
           have applications in film sensing and nanocomposite fibers in smart textiles, because
           nanocomposite materials show high conductivity and multidimensional functioning.
           We can control the dynamic percolation of CNTs in the polymer matrix before the
           addition of a second nanofiller to a polymer/CNT composite [28]. It was also observed
           that different nanofillers were uniformly distributed into the polymeric host matrix.
           Ternary CNT-based nanocomposite filaments were sensitive and act as multi-
           functional strain sensors in smart textiles.


           7.5.2  Poly(2-phenyl-1,4-xylylene) (PPPX) based nanocomposites
           A new composite-based chemiresistive sensor that was developed by doping with
           free-base and metallated porphyrins instead of organic Lewis acids with conducting
           polymers was developed for the identification of four organic solvents and used as
           standard analytes: propanone, ethylacetate, ethanol, and toluene. A dynamic head-
           space technique was used for the sampling, and the experiments were carried out
           at 35°C. Dry air was used for purging of the sensor chamber, and the flow was
           maintained at 0.6 L min  1  (61% relative humidity). Different combination of conduc-
           tive polymer, porphyrin, and Lewis acid was deposited on the sensors for evaluation of
           the performance of the sensor. The sensors are classified as sensor 1, porphyrin
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