A Polyaniline-Based Selective Hydrogen Sensor

Conn, Costa; Sestak, S.; Baker, Anthony T.; Unsworth, J.

doi:10.1002/(sici)1521-4109(199811)10:16<1137::aid-elan1137>3.0.co;2-1

Cited by 59 publications

(35 citation statements)

References 13 publications

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“…These reactions lead to the protonation of polyaniline nitrogen atoms, resulting in more delocalized charge carriers (polarons and bipolarons) on the backbone for conduction and an increase of the film conductivity. It has also been suggested that the resistance change is caused by the formation of water [25]. The effects of water on the conductivity of polyaniline are well known [26,27] and have been established from nuclear magnetic resonance (NMR) spectroscopy studies that presence of water molecules in the polyaniline facilitates the charge transfer in the polyaniline backbone leading to an increase in polymer's conductivity.…”

Section: Resultsmentioning

confidence: 99%

Doped and dedoped polyaniline nanofiber based conductometric hydrogen gas sensors

Sadek

Włodarski

Kalantar‐zadeh

et al. 2007

Sensors and Actuators A: Physical

141

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Template-free, rapid polymerisation was employed to synthesize polyaniline nanofibers using chemical oxidative polymerisation of aniline, with HCl as a dopant. The doped and dedoped nanofibers were deposited onto conductometric sapphire transducers for gas sensing applications. The sensors were exposed to various concentrations of hydrogen (H 2 ) gas at room temperature. The sensitivity was measured to be 1.11 for doped and 1.07 for dedoped polyaniline nanofiber sensors upon exposure to 1% H 2 . Fast response times of 28 seconds and 32 seconds were observed for dedoped and doped sensors respectively. The dedoped nanofiber sensor outperforms the doped sensor in terms of baseline stability and repeatability. Due to its room temperature operation, the gas sensor is promising for environmental applications.

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Section: Resultsmentioning

confidence: 99%

Doped and dedoped polyaniline nanofiber based conductometric hydrogen gas sensors

Sadek

Włodarski

Kalantar‐zadeh

et al. 2007

Sensors and Actuators A: Physical

141

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“…Surprisingly, an opposite effect was observed for PPY/Pd composites [78], PANI [79] and PANI/PtO composites [80]. The mechanism of these effects is not clear, however it was suggested that the conductivity increase is caused by formation of water inside the CP film.…”

Section: Conducting Polymers With Affinity To Gasesmentioning

confidence: 97%

“…Composites of CP with metal [78] or metaloxide [63,80,[89][90][91][92][93] nanoparticles, carbon nanotubes [94][95][96], organic and metalorganic [97] compounds and insulating polymers [98][99][100] provide new analytical possibilities. Metaloxide particles are assumed to form n-p hetero junctions with the CP with a depletion region.…”

Section: Conducting Polymers With Affinity To Gasesmentioning

confidence: 99%

Conducting polymers in chemical sensors and arrays

Lange¹,

Roznyatovskaya²,

Mirsky³

2008

Analytica Chimica Acta

850

434

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“…To enhance the operating of these sensors, composites of CP and metal oxides [46,[128][129][130][131][132][133] and nanoparticles and carbon nanotubes [134][135][136] have been proposed and tested.…”

Section: Affinity To Gases and Vaporsmentioning

confidence: 99%

Conducting Polymers as Artificial Receptors in Chemical Sensors

Lange

Roznyatovskaya

Hao

et al. 2010

Artificial Receptors for Chemical Sensors

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Conducting polymers are commonly used materials in chemical and biological sensors. These materials possess receptor as well as transducer functions [1]. Typical examples of conducting polymers (CPs) include polythiophenes, polypyrroles, polyanilines, and polyphenylenes. Such polymers show some intrinsic receptor properties towards analytes that can react/interact with the polymer, like, for example, redox active or acidic/basic gases. Oxidation/reduction and in some cases protonation/ deprotonation introduces/removes charge carriers in the conjugated backbone, whereas conformational changes alter the planarity of the conjugated backbone, which leads to changes in the mobility of the charge carriers. Figure 12.1 demonstrates the example of PANI (polyaniline), showing the influence of redox potential and pH on the interconversion between the different forms of PANI.These changes can be detected by in situ resistance, UV-vis, IR, or fluorescence measurements. Direct interactions with the p-system often produce very large signal changes; however, they are quite non-specific. A possible way to introduce some selectivity in these polymers is to modify their conjugated backbone with receptors.Usually, receptors can be introduced into a polymer backbone either after polymerization or directly to monomer, which is polymerized or copolymerized. The synthetic availability and the ability to polymerize the monomer under certain conditions are the most common limitations in the choice of a derivative with receptor group. Some classes of these receptors are discussed in Section 12.4. Doping of CPs by counter ions bearing the required receptor [2-8], the inclusion of ionophores into the polymer matrix [9], and the chemical linkage of ligands or receptor units to the polymer backbone [10] are also applied to enhance the selectivity and sensitivity of CPs. Receptors attached to the p-system via some short side chain can communicate with the p-system of the polymer by, for example, electron donating/withdrawing, electrostatic interactions or by inducing conformational changes upon analyte binding. As there is no direct interaction with the polymer backbone, the signal change may be smaller, but also much more specific. Artificial Receptors for Chemical Sensors. Edited

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A Polyaniline-Based Selective Hydrogen Sensor

Cited by 59 publications

References 13 publications

Doped and dedoped polyaniline nanofiber based conductometric hydrogen gas sensors

Doped and dedoped polyaniline nanofiber based conductometric hydrogen gas sensors

Conducting polymers in chemical sensors and arrays

Conducting Polymers as Artificial Receptors in Chemical Sensors

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