X-ray photoelectron spectroscopic studies of conducting polyaniline, poly bisphenol A carbonate and electrochemically synthesized composite of the two

Bhattacharyya, Arpan; Roy, Rita; Sk, Sen; Sen, Shrabanee; Chakraborty, A.K.; Tk, Bhattacharyya

doi:10.1016/s0042-207x(97)00169-3

Cited by 11 publications

(6 citation statements)

References 8 publications

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“…The second peak at 73.4 eV could be assigned to the reduced Pt-PANI species described formerly, which seems to be stable under the applied hydrogen pre-treatment conditions. The observed N 1s binding energy (BE = 399.3 eV, Figure 2), which could be assigned to [-NH-], [10,22] definitely reveals the existence of the benzenoid, fully reduced form of PANI, and this is consistent with the application of the reducing agent THPC during the syntheses. Thus, one could assume that this catalyst, prepared by the sol-method, mostly comprises very small metallic Pt species or even atoms on the leucoemeraldine form (Scheme 2; x = 1) of PANI.…”

Section: In Depth Characterization By Xps and Exafs/ Xanes X-ray Photsupporting

confidence: 56%

Carbon‐Carbon Double Bond versus Carbonyl Group Hydrogenation: Controlling the Intramolecular Selectivity with Polyaniline‐Supported Platinum Catalysts

et al. 2008

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The use of polyaniline (PANI) as catalyst support for heterogeneous catalysts and their application in chemical catalysis is hitherto rather poorly known. We report the successful synthesis of highly dispersed PANI-supported platinum catalysts (particle sizes between 1.7 and 3.7 nm as revealed by transmission electron microscopy, TEM) choosing two different approaches, namely (i) deposition-precipitation of H 2 PtCl 6 onto polyaniline, suspended in basic medium (DP method) and, (ii) immobilization of a preformed nanoscale platinum colloid on polyaniline (sol-method). The PANI-supported platinum catalysts were applied in the selective hydrogenation of the a,b-unsaturated aldehyde citral. In order to benchmark their catalytic performance, citral hydrogenation was also carried out by using platinum supported on the classical support materials silica (SiO 2 ), alumina (Al 2 O 3 ), active carbon and graphite. The relations of the structural characteristics and surface state of the catalysts with respect to their hydrogenation properties have been probed by EXAFS and XPS. It is found that the DP method yields chemically prepared PtO 2 on polyaniline and, thus, produces a highly dispersed and immobilized Adams catalyst (in the b-PtO 2 form) which is able to efficiently hydrogenate the conjugated C=C bond of citral (selectivity to citronellal = 87%), whereas reduction of the C=O group occurs with polyanilinesupported platinum (selectivity to geraniol/nerol = 78%) prepared via the sol-method. The complete reversal of the selectivity between the preferred hydrogenation of the conjugated C=C or C=O group is not only particularly useful for the selective hydrogenation of a,b-unsaturated aldehydes but also unveils the great potential of conducting polymer-supported precious metals in the field of hitherto barely investigated chemical catalysis.

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Section: In Depth Characterization By Xps and Exafs/ Xanes X-ray Photsupporting

confidence: 56%

Carbon‐Carbon Double Bond versus Carbonyl Group Hydrogenation: Controlling the Intramolecular Selectivity with Polyaniline‐Supported Platinum Catalysts

et al. 2008

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“…Gaussian function describing separate components prescribed to the chemical form) into few subcomponents. For a polyaniline emeraldine base (PANI base) the number of nitrogen amine groups (−NH−) situated at the binding energy equals 399.6 eV and should approach the number of nitrogen imine groups (N−) situated at the binding energy equal to 398.5 eV. − The presence of about equal amounts of imine and amine nitrogens is consistent with the intrinsic oxidation state of PANI emeraldine base − This residual high binding energy tail above 400 eV in the spectra is associated with surface oxidation products or weakly charge-transfer-complexed oxygen species (N + ) .…”

Section: Resultsmentioning

confidence: 86%

“…Similarly, the total C 1s spectra can be decomposed into few carbon forms: (i) carbon bonded to carbon (C−C) (284.4 eV); (ii) carbon singly bonded to oxygen or nitrogen (CO/CN) (286.1 eV); (iii) carbonyl carbon (CO) (287.5 eV); (iv) ester carbon (289.3 eV). , The results of recorded C 1s photoelectron spectra decomposition for the polyanilines are shown in Table .…”

Section: Resultsmentioning

confidence: 99%

“…Due to the variety of applications and complexity of structure, constantly growing research has been devoted to disclose new emerging chemistry and physical properties of these materials. Among all the available techniques, the most commonly applied methods were the electron spectroscopy − and infrared (IR) spectroscopy. − It seems that electron spectroscopy methods, like X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and electron energy loss spectroscopy (EELS), combined with infrared spectroscopy can give answers to many questions on the electronic structure of the surface region of conjugated polymers.…”

Section: Introductionmentioning

confidence: 99%

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Determination of the Inelastic Mean Free Path of Electrons in Different Polyaniline Samples

et al. 1999

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Polyaniline specimens, emeraldine sulfate, emeraldine hydrochloride, and emeraldine base, were characterized by infrared spectroscopy, X-ray photoelectron spectroscopy, elastic peak electron spectroscopy, and density measurements using helium pycnometry. This work has been stimulated by a considerable interest in potential technological applications of polyaniline. The chemical state of polyaniline has been verified with infrared spectroscopy. X-ray spectroscopy was used for the qualitative and quantitative surface composition analysis of studied samples. The inelastic mean free path of electrons has been determined from the measurements of the elastic electron backscattering probability. This is one of the most frequent applications of elastic peak electron spectroscopy. The inelastic mean free path is needed for the quantitative analysis of polyaniline surface using electron spectroscopies. The method of elastic peak electron spectroscopy utilizes the theoretical model of the electron transport, accounting for the multiple elastic scattering events in the studied material. The inelastic mean free path values have been measured in the energy range 400−1600 eV. The resulting dependence has been compared to the values obtained using the G1 predictive formula of Gries.

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“…The main doublet with the Cl 2p 3/2 peak lying at 197.7 eV corresponds to ionic species (Cl − ). The doublet with the Cl 2p 3/2 peak lying at 200.3 eV can be assigned to covalent species 30. Then, all chlorine atoms introduced in the plasma film after exposition to HCl vapours are not involved in the doping process.…”

Section: Resultsmentioning

confidence: 99%

Effect of Fluorine Substitution of Aniline Ring on Pulsed Plasma Polymer Growth and Structure

Mérian

Debarnot

Poncin-Epaillard

2011

Plasma Processes & Polymers

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The pulsed plasma polymerization of 3‐fluoroaniline is investigated. The resulting polymer is characterized in terms of growth kinetics and chemical structure using X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, profilometry and quartz crystal microgravimetry. The characteristics of plasma polyfluoroaniline are compared with those of plasma polyaniline. The doping mechanism of these two plasma polymers is also examined. The results showed that the substitution of the aniline ring in meta position by a fluorine atom results in obtaining a more linear polymer structure. However, the doping is more efficient for polyaniline than for polyfluoroaniline. Moreover, discharge power and on‐time are the major determinants of the growing and the structure of the polymer.

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X-ray photoelectron spectroscopic studies of conducting polyaniline, poly bisphenol A carbonate and electrochemically synthesized composite of the two

Cited by 11 publications

References 8 publications

Carbon‐Carbon Double Bond versus Carbonyl Group Hydrogenation: Controlling the Intramolecular Selectivity with Polyaniline‐Supported Platinum Catalysts

Carbon‐Carbon Double Bond versus Carbonyl Group Hydrogenation: Controlling the Intramolecular Selectivity with Polyaniline‐Supported Platinum Catalysts

Determination of the Inelastic Mean Free Path of Electrons in Different Polyaniline Samples

Effect of Fluorine Substitution of Aniline Ring on Pulsed Plasma Polymer Growth and Structure

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