Conductive polymer

About: Conductive polymer is a research topic. Over the lifetime, 21817 publications have been published within this topic receiving 692491 citations. The topic is also known as: intrinsically conducting polymer & ICP.

ZnO assisted polyaniline nanofibers and its application as ammonia gas sensor

Abstract: A novel route for the synthesis of polyaniline nanofibers in the presence of varying amounts of zinc oxide has been reported in this paper. The homogeneous PANI nanofibers were prepared through template approach, in which the ZnO nanoparticles were used as template. Structural, optical and morphological analysis of synthesized nanofibers was carried out using X-ray diffraction, UV–vis, IR spectroscopy and FESEM techniques. The thick films of the synthesized polyaniline powder were deposited on alumina substrate and their sensing response to ammonia gas was investigated. Optimum sensing response was achieved with PANI nanofibers synthesized in the presence of 30 wt% ZnO powder. The sensing response of fabricated sensor was proportional to the ammonia gas concentration and exhibited excellent selectivity toward ammonia gas.

Biocompatibility implications of polypyrrole synthesis techniques.

Abstract: Polypyrrole (PPy) is an inherently conducting polymer that has shown great promise for biomedical applications within the nervous system. However, to effectively use PPy as a biomaterial implant, it is important to understand and reproducibly control the electrical properties, physical topography and surface chemistry of the polymer. Although there is much research published on the use of PPy in various applications, there is no systematic study linking the methodologies used for PPy synthesis to PPy's basic polymeric properties (e.g., hydrophilicity, surface roughness), and to the biological effects these properties have on cells. Electrochemically synthesized PPy films differ greatly in their characteristics depending on synthesis parameters such as dopant, substrate and thickness, among other parameters. In these studies, we have used three dopants (chloride (Cl), tosylate (ToS), polystyrene sulfonate (PSS)), two substrates (gold and indium tin oxide-coated glass), and a range of thicknesses, to measure and compare the biomedically important characteristics of surface roughness, contact angle, conductivity, dopant stability and cell adhesion (using PC-12 cells and Schwann cells). As predicted, we discovered large differences in roughness depending on the dopant used and the thickness of the film, while substrate choice had little effect. From contact angle measurements, PSS was found to yield the most hydrophilic material, most likely because of free charges from the long PSS chains exposed on the surface of the PPy. ToS-doped PPy films were tenfold more conductive than Cl- or PSS-doped films. X-ray photoelectron spectroscopy studies were used to evaluate dopant concentrations of PPy films stored in water and phosphate buffered saline over 14 days, and conductance studies over the same timeframe measured electrical stability. PSS proved to be the most stable dopant, though all films experienced significant decay in conductivity and dopant concentration. Cell adhesion studies demonstrated the dependence of cell outcome on film thickness and dopant choice. The strengths and weaknesses of different synthesis parameters, as demonstrated by these experiments, are critical design factors that must be leveraged when designing biomedical implants. The results of these studies should provide practical insight to researchers working with conducting polymers, and particularly PPy, on the relationships between synthesis parameters, polymeric properties and biological compatibility.

High performance polymeric charge recombination layer for organic tandem solar cells

Abstract: We report on inverted polymer tandem solar cells wherein the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), modified at one interface with ethoxylated polyethylenimine (PEIE), acts as an efficient charge recombination layer. This recombination layer shows very low optical absorption, high electrical conductivity, and a large work function contrast of 1.3 eV between its top and bottom interfaces. Its use yields tandem cells in which the open-circuit voltage is the sum of that of individual cells. The fill factor of tandem cells connected in series is found to be larger than that of single-junction cells. Its simple polymeric composition and its unprecedented performance make it a promising component for emerging organic photovoltaic technologies.

Vapor-phase polymerization of pyrrole and thiophene using iron (III) sulfonates as oxidizing agents

Abstract: Vapor phase polymerization is a versatile technique that can be used to obtain highly conducting coatings of conjugated polymer on both conducting and nonconducting substrates. This is demonstrated here by preparation of polypyrrole, polybithiopene, and polyterthiopene, coatings that otherwise must be prepared electrochemically in order to achieve the desired high conjugation. The method is based on the use of organic ferric sulfonates as oxidant as these salts easily form smooth, noncrystalline films. By proper choice of the sulfonate anion, the oxidizing power of the ferric salt can be varied over a wide range. The described technique can easily be adapted to different patterning techniques.