Determination of the electronic conductivity of polybithiophene films at different doping levels using in situ electrochemical impedance measurements

2003 ◽  
Vol 83 (11) ◽  
pp. 2178-2180 ◽  
Author(s):  
Germà Garcia-Belmonte ◽  
Juan Bisquert ◽  
George S. Popkirov
Keyword(s):  
Electrochemical Impedance ◽  
Electronic Conductivity ◽  
Impedance Measurements

A Facile In-Situ Development of L-Valine Film onto the Surface of Carbon Paste Electrode Towards the Detection of Environmentally Hazardous 4-Amino Phenol

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
T. Venu Gopal ◽  
Tukiakula Madhusudana Reddy ◽  
P. Shaikshavali ◽  
G. Venkataprasad ◽  
P. Gopal
Keyword(s):  
Cyclic Voltammetry ◽  
Carbon Paste Electrode ◽  
Electrochemical Impedance ◽  
Limit Of Detection ◽  
Small Scale ◽  
Carbon Paste ◽  
Relative Standard ◽  
Paste Electrode

Abstract A small scale of environmentally hazardous 4-aminophenol can show significant impact on human health. Hence, in the present work, we have designed L-Valine film (Vf) modified carbon paste electrode (Vf/CPE) for the determination of 4-aminophenol. Herein, a facile in-situ L-Valine film was developed by electrochemical polymerization method onto the surface of bare carbon paste electrode (BCPE) with the help of cyclic voltammetry (CV) technique. A two-folds of electrochemical peak current enhancement was achieved at Vf/CPE in comparison with BCPE towards the determination of 4-aminophenol in optimum pH 7.0 of phosphate buffer solution (PBS). This was achieved due to the large surface area and conductive nature of Vf/CPE, which was concluded through the techniques of cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The effect of pH of buffer and scan rate studies were successfully studied. Morphological changes of BCPE and Vf/CPE was studied with the help of scanning electron microscopy (SEM). The formation of Vf on CPE was also analyzed by Fourier transform infrared (FTIR) spectra. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of 4-aminophenol were estimated with the aid of chronoamperometry (CA) technique and was found to be 9.8 μM and 32 μM, respectively. Finally the proposed method was found to have satisfactory repeatability, reproducibility and stability results with low relative standard deviation (RSD) values.

In-situ electrochemical impedance measurements of corroding stainless steel in high subcritical and supercritical water

2019 ◽  
Vol 150 ◽  
pp. 9-16 ◽  
Author(s):  
J. Macák ◽  
R. Novotný ◽  
P. Sajdl ◽  
V. Bystrianský ◽  
L. Tůma ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Supercritical Water ◽  
Electrochemical Impedance ◽  
Impedance Measurements

scholarly journals New Electrode Based on Polymer Bacteria Modified Aluminum for Degradation of Phenol

2021 ◽  
Author(s):  
Raja MAALLAH ◽  
Raja MAALLAH
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Polymer Matrix ◽  
Electrochemical Impedance ◽  
Aluminum Electrode ◽  
Simultaneous Production ◽  
Modified Aluminum Electrode

The aims of this work were to examine the new electrode, based on polymer bacteria modified aluminum electrode for simultaneous production of electricity and degradation of phenol. This electrode is based aluminum modified by bacteria inserted in the polymer matrix, developed in situ on the surface. This electrode, designated subsequently by bacteria-polymer-aluminum, Showed stable response and was characterized with voltametric methods, as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental results revealed that the prepared electrode could be a feasible for degradation of hazardous phenol pollutants. The sensor was successfully applied to the determination of phenol in a real sample with satisfactory results.

A facial in-situ approach to synthesize Ti2Nb10O29@PANI core-shell microspheres for high performance lithium ion battery anodes

2021 ◽  
Vol 11 (5) ◽  
pp. 749-757
Author(s):  
Luying He ◽  
Xin Shen ◽  
Yang Yao ◽  
Hui Li
Keyword(s):  
Electrochemical Properties ◽  
Lithium Ion Battery ◽  
Electrode Material ◽  
Electrochemical Impedance ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Transfer Resistance ◽  
Composite Microspheres ◽  
Pani Composite

Polyaniline (PANI) wrapped Ti2Nb10O29 (TNO) micro-spherical composites were successfully synthesized via a solvothermal approach combined with a facial post in-situ polymerization method. Effects of different amounts of the PANI coatings on the composite microspheres’ electrochemical properties were studied in detail. Results showed that the electrochemical performance of TNO@PANI anodes with 5 wt% PANI is the optimum among all the samples, giving capacity values as high as 272 mAh/g (1 C) and 190.1 mAh/g (20 C), respectively. Moreover, the electrochemical impedance measurements exhibited that 5 wt% TNO@PANI composite electrode material possess a weaker charge transfer resistance. This indicates that an appropriate amount of polyaniline coating can effectively improve the electronic conductivity of TNO microspheres and subsequently the electrochemical properties. In this work, we have demonstrated that 3D TNO@PANI composite microspheres not only deliver a higher initial Columbic efficiency but also can serve as next-generation lithium-ion battery electrode material with enhanced rate performance.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

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