A Study on the Synthesis, Characterization and Properties of Polyaniline Nanofibers Using Ferric Chloride as both Oxidant and Dopant

2013 ◽  
Vol 807-809 ◽  
pp. 2757-2761
Author(s):  
Hang Jun Ding ◽  
Zhou Yang ◽  
Huai Yang ◽  
Mei Xiang Wan
Keyword(s):  
Ferric Chloride ◽  
Main Chain ◽  
Ftir Spectra ◽  
High Conductivity ◽  
Probe Method ◽  
Synthetic Methods ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Polyaniline Nanofibers ◽  
Uv Visible

PANI nanofibers with a really nanoscaled diameter of 20 ~ 30 nm and a high conductivity of 100 S/cm were successfully prepared by using FeCl3 · 6H2O as oxidant at the acidic dopant-free. Compared with other synthetic methods for nanostructures, this approach is most simple and cheap because of FeCl3 · 6H2O having two-function of oxidant and dopant at the same time, resulting in further simplifying reaction reagents. Characterizations of UV-visible, FTIR spectra, XRD as well as conductivity measured by four-probe method definitely proved the nanofibers oxidized by FeCl3 as oxidant at dopant-free are identical to the emeraldine salt form of PANI, although without external acidic dopant, and Cl- anion is incorporated the PANI main chain as counter-ion.

scholarly journals Application of an enzymatic cascade reaction for the synthesis of the emeraldine salt form of polyaniline

2021 ◽  
Author(s):  
Minoru Kurisu ◽  
Reinhard Kissner ◽  
Masayuki Imai ◽  
Peter Walde
Keyword(s):  
Cascade Reaction ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Experimental Conditions ◽  
Peroxidase Isoenzyme ◽  
Large Unilamellar Vesicles ◽  
Dark Green ◽  
Catalyzed Oxidation ◽  
Reference Reaction

AbstractThe synthesis of the emeraldine salt form of polyaniline (PANI-ES) from aniline with Aspergillus sp. glucose oxidase (GOD), d-glucose, dissolved O2, and horseradish peroxidase isoenzyme C (HRPC) in the presence of large unilamellar vesicles of AOT (sodium bis-(2-ethylhexyl)sulfosuccinate) as templates at pH = 4.3 and T ~ 25 °C was investigated in a systematic way. In this cascade reaction mixture, the oxidation of aniline is catalyzed by HRPC with H2O2 that is formed in situ as byproduct of the GOD-catalyzed oxidation of d-glucose with O2. Under the elaborated experimental conditions which we considered ideal, the formation of PANI-ES products is evident, as judged by UV/Vis/NIR and EPR measurements. Comparison was made with a reference reaction, which was run under similar conditions with added H2O2 instead of GOD and d-glucose. Although the reference reaction was found to be superior, with the cascade reaction, PANI-ES products can still be obtained with high aniline conversion (> 90%) within 24 h as stable dark green PANI-ES/AOT vesicle dispersion. Our results show that the in situ formation of H2O2 does not prevent the inactivation of HRPC known to occur in the reference reaction. Moreover, the GOD used in the cascade reaction is inactivated as well by polymerization intermediates.

scholarly journals Reproduction of vesicles coupled with a vesicle surface-confined enzymatic polymerisation

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Minoru Kurisu ◽  
Harutaka Aoki ◽  
Takehiro Jimbo ◽  
Yuka Sakuma ◽  
Masayuki Imai ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
External Solution ◽  
Molecular Assembly ◽  
Darwinian Evolution ◽  
Assembly Systems ◽  
Emeraldine Salt ◽  
Minimal Cell ◽  
Salt Form ◽  
Reproduction System

Abstract Molecular assembly systems that have autonomous reproduction and Darwinian evolution abilities can be considered as minimal cell-like systems. Here we demonstrate the reproduction of cell-sized vesicles composed of AOT, i.e., sodium bis-(2-ethylhexyl) sulfosuccinate, coupled with an enzymatic polymerisation reaction occurring on the surface of the vesicles. The particular reaction used is the horseradish peroxidase-catalysed polymerisation of aniline with hydrogen peroxide as oxidant, which yields polyaniline in its emeraldine salt form (PANI-ES). If AOT micelles are added during this polymerisation reaction, the AOT - PANI-ES vesicles interact with the AOT molecules in the external solution and selectively incorporate them in their membrane, which leads to a growth of the vesicles. If the AOT vesicles also contain cholesterol, the vesicles not only show growth, but also reproduction. An important characteristic of this reproduction system is that the AOT-based vesicles encourage the synthesis of PANI-ES and PANI-ES promotes the growth of AOT vesicles.

Synthesis and Characterization of Polyaniline -Crooked Gold Nanocomposite with Reduced Conductivity

2009 ◽  
Vol 5 ◽  
pp. 79-85 ◽  
Author(s):  
Ranjit R. Hawaldar ◽  
M. Kulkarni ◽  
Sandesh R. Jadkar ◽  
Umapada Pal ◽  
Dinesh Amalnerkar
Keyword(s):  
Oxidative Polymerization ◽  
Emeraldine Salt ◽  
One Dimensional ◽  
Nano Gold ◽  
Doped Polyaniline ◽  
Salt Phase ◽  
Uv Visible ◽  
Gold Nanocomposites

Conducting Polyaniline (Pani)-crooked Gold nanocomposites were synthesized by in situ chemo-oxidative polymerization of aniline with previously made crooked gold nanoparticles by using ammonium per oxidisulphate as oxidizing agent and p-toluene sulphonic acid (p-TSA) as dopant. The formation of nano gold was established by UV-visible spectroscopy with a SPR peak at 512 nm and crooked morphology was confirmed by TEM. Spectroscopic analysis confirmed the formation of the conducting emeraldine salt phase of the polymer. Due to clustering of composite nanoparticles, the polymer composite formed one-dimensional rod-like morphologies. Thermogravimetric analysis revealed a typical three-step decomposition pattern pertaining to polyaniline emeraldine salt. The conductivity of the nanocomposite was found to be lower (2.47 S/cm) than the virgin p-TSA doped polyaniline (5.55 S/cm).

The influence of heat treatment on the semi-crystalline structure of polyaniline Emeraldine-salt form

2017 ◽  
Vol 1128 ◽  
pp. 707-717 ◽  
Author(s):  
Lilian R. de Oliveira ◽  
Lizandro Manzato ◽  
Yvonne P. Mascarenhas ◽  
Edgar A. Sanches
Keyword(s):  
Heat Treatment ◽  
Crystalline Structure ◽  
Emeraldine Salt ◽  
Salt Form

scholarly journals The Use of Le Bail Method to Analyze the Semicrystalline Pattern of a Nanocomposite Based on Polyaniline Emeraldine-Salt Form andα-Al2O3

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Edgar A. Sanches ◽  
Adriano de S. Carolino ◽  
Amanda L. dos Santos ◽  
Edson G. R. Fernandes ◽  
Daniela M. Trichês ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Pure Pani ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Absorption Bands ◽  
Physical Deposition ◽  
Average Size

Ceramic nanocomposites constituted by a matrix ofα-Al2O3microparticles reinforced by polyaniline emeraldine-salt form (PANI-ES) nanoparticles were prepared byin situpolymerization and characterized structural and morphologically. Peaks related to both materials were observed through XRD technique: PANI-ES presented peaks at2θ= 8.9, 14.9, 20.8, 25.3, 27.1, and 30.0° and inα-Al2O3phase peaks were found at2θ= 25.6, 35.2, 37.9, 43.5, 52.6, 57.6, and 68.1°. Nanocomposite crystallinity percentage was estimated around 70%. SEM showed a polymerization of PANI-ES over alumina plates. By Le Bail method it was observed that PANI-ES andα-Al2O3have crystallite average size around, respectively, 41 and 250 Å. By FTIR analysis characteristic absorption bands of both materials were identified. Additional bands indicating new chemical bonds were not observed, suggesting that nanocomposite was formed by physical deposition. Nanocomposite DC electrical conductivity was found around 0.24 S/cm (against1.84×10-4 S/cm for pure PANI-ES), showing an increase of about 1,300 times compared to the pure PANI-ES at room temperature. Thus, this paper showed that both materials have kept its original structural characteristics and exhibited high electrical conductivity when combined in nanocomposite form.

Preparation and characterization of polyaniline–cadmium sulfide nanocomposite for gas sensor application

2017 ◽  
Vol 31 (26) ◽  
pp. 1750234 ◽  
Author(s):  
Selma M. H. Al-Jawad ◽  
Sewench N. Rafic ◽  
Mustafa M. Muhsen
Keyword(s):  
Cadmium Sulfide ◽  
Oxidative Polymerization ◽  
Sol Gel ◽  
High Resistivity ◽  
Emeraldine Salt ◽  
Electrical Measurements ◽  
Salt Form ◽  
Operation Temperature ◽  
Cds Nanocomposites

Polyaniline (PANI) was prepared by chemical oxidative polymerization of aniline monomers as emeraldine salt form. By the same method, polyaniline–cadmium sulfide nanocomposites were synthesized in the presence of different percentages (10–50 wt.%) of cadmium sulfide (CdS) which was prepared by using sol–gel method. The optical band gap was decrease with increasing of CdS concentration, that is obtained from UV-VIS measurements. From SEM and AFM, there is uniform distribution for cadmium sulfide nanoparticles in the PANI matrix. The electrical measurements of nanocomposites exhibit the effect of crystallite size and the high resistivity of CdS on the resistivity of nanocomposites. Emeraldine salt PANI, CdS and PANI–CdS nanocomposites were investigated as gas sensors. From this investigation, the sensitivity of PANI–CdS for NO2 gas increase with the increasing of operation temperature and the optimum sensitivity was obtained at 200[Formula: see text]C. The sensitivity of nanocomposites at best temperature (200[Formula: see text]C) was increased and faster response time with the increasing of CdS contents.

scholarly journals Structural Characterization of Emeraldine-Salt Polyaniline/Gold Nanoparticles Complexes

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
E. A. Sanches ◽  
J. C. Soares ◽  
R. M. Iost ◽  
V. S. Marangoni ◽  
G. Trovati ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Electrostatic Interactions ◽  
Sodium Citrate ◽  
X Ray Diffraction ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Au Nps ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Polyamidoamine Dendrimers

Gold nanoparticles (Au NPs) stabilized with polyamidoamine dendrimers (Au-PAMAM) or sodium citrate (Au-CITRATE) were synthesized and complexed with polyaniline emeraldine-salt form (ES-PANI). The complexes were characterized using structural and morphological techniques, including X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Zeta Potential analyses, and Fourier-Transformed Infrared spectroscopy (FTIR). When the Au-CITRATE NPs are added to the polymeric solution, the formation of a precipitate is clearly observed. The precipitate exhibited a different morphology from that found for ES-PANI and Au-CITRATE NPs, suggesting the formation of ES-PANI coating over the surface of Au-CITRATE NPs. On the other hand, when the Au-PAMAM NPs are incorporated into the ES-PANI solution, none interaction was observed, probably due to the repulsive electrostatic interactions, being the organization of the ES-PANI chains unaffected by the presence of the Au-PAMAM NPs.

Novel Surfactant Free and Solid State Polymerization to Dendritic Polyaniline Nanofibers

2008 ◽  
Vol 47-50 ◽  
pp. 638-641 ◽  
Author(s):  
Xu Sheng Du ◽  
Cui Feng Zhou ◽  
Zong Wen Liu ◽  
Simon P. Ringer ◽  
Yiu Wing Mai
Keyword(s):  
Solid State ◽  
Growth Mechanism ◽  
Solid State Reaction ◽  
Fiber Diameter ◽  
Emeraldine Salt ◽  
Polyaniline Nanofibers ◽  
Good Crystallinity ◽  
Solid State Polymerization ◽  
Ft Ir

A novel solid state and surfactant-free method has been developed for synthesis of polyaniline superstructure composed of dendritic nanofibers. The good crystallinity of the product is confirmed by XRD, while FT-IR analyses indicate the formation of highly doped emeraldine salt of polyaniline product. Microscopic observations show that the product is in the form of polyaniline dendrites with a less-than-40 nm fiber diameter. The unique growth mechanism of the superstructure in solid-state reaction has been discussed.

Synthesis and effect of secondary dopant on the conductivity of conducting polymer polyaniline

2013 ◽  
Vol 33 (9) ◽  
pp. 785-792 ◽  
Author(s):  
Kedir Mamma ◽  
Khalid Siraj ◽  
Nathan Meka
Keyword(s):  
Electrical Conductivity ◽  
Conductivity Measurement ◽  
Emeraldine Base ◽  
Cyclic Voltammograms ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Aniline Monomer ◽  
Electrical Conductivity Measurement ◽  
Secondary Doping ◽  
Ft Ir

Abstract Polyaniline (PANI) in its emeraldine salt form was synthesized by chemical method from aniline monomer in the presence of HCl mixed with LiCl and ammonium persulfate as oxidant. Then, a portion of sample was dedoped with NH3 solution and another equal portion was separately postdoped with secondary dopants, such as H2SO4 and HClO4, respectively. Finally, the dried samples of PANI prepared in all its three different forms (emeraldine salt form, undoped emeraldine base, and the two secondary doped forms of PANI) were characterized by UV-visible spectroscopy, cyclic voltammetry (CV) techniques, Fourier transform infrared (FT-IR) spectroscopy, and electrical conductivity measurement. The cyclic voltammograms of PANI in its emeraldine base (PANI-EB) determined the electrochemical behavior and the growth mechanisms of the polymer. The FT-IR and UV-vis spectra confirmed the expected structural modification up on doping, undoping, and postdoping processes of the polymer. Their measured electrical conductivities were from 0.02 for undoped, 156 for primary doped form, and increasing from 158 to 257 S/cm for those secondary doped PANI. The influence of secondary doping on the electrical conductivity was also investigated from their spectroscopic data which shows dramatic rise in conductivity. The result also shows that secondary doping increased the π conjugation.

scholarly journals TRANSFORMATION OF THE NATURE OF THE CONDUCTIVITY OF HIGHLY CONDUCTIVE CHALCOGENIDE MELTS TO TOWARDS THEIR ELECTROLYTIC CAPACITY

2021 ◽  
Vol 1 (48) ◽  
pp. 208-216
Author(s):  
Melnik N ◽  
◽  
Mustyatsa O ◽  
Keyword(s):  
Electrical Conductivity ◽  
Systematic Error ◽  
Direct Current ◽  
Differential Method ◽  
High Conductivity ◽  
Probe Method ◽  
Metal Chalcogenides ◽  
Accuracy Class ◽  
Iron Chalcogenides ◽  
Polarization Characteristics

Ibe aim of this work is to study the nature of the conductivity of melts of iron chalcogenides (Fe-Se, Fe-Te, FeS-Na2S) and the conditions of its possible transformation in order to bring the high-conductivity melt to a state suitable for electrolytic decomposition into metal and chalcogen. To solve this problem, a set of methods was used - electrical conductivity (ж), thermo-EMF (a), polarization characteristics (І-V) and electrolysis (n). ж of high-conductivity melts was investigated by the four-probe method on a direct current in a quartz U-shaped cell of capillary type with graphite electrodes and molybdenum current leads in the direct current mode. The systematic error due to the accuracy class of the devices is 1%; random - does not exceed 1%. Low ж melts were studied by the two-probe AC method. Due to the high chemical aggressiveness of FeS-Na2S melts, a measuring cell with an alundum capillary was developed. Random error when measuring ж two-probe method on alternating current is 3%, systematic - is within 2%. Thermo-EMF was measured by the differential method with respect to tungsten probes. The temperature difference between the probes was recorded by a differential thermocouple. Systematic error in measuring thermo-EMF was 2%, random - 1.5%. Polarization characteristics were removed by the method of direct current in a simple cell without separation of electrode spaces. In cells of this type in an argon medium over the melt and experiments on electrolysis were performed. It is established that all samples are characterized by significant values of electrical conductivity (of the order of thousands of Sm/cm) and its negative temperature coefficients; the absolute thermo-EMF of all samples is units of цУ/deg. Melts are qualified as electron-ion (polyfunctional) conductors with a predominant metallic contribution to the conductivity. The introduction of Na2S into the FeS melt leads to a decrease in electrical conductivity and the transformation of its temperature dependence to the inherent ionic compounds. The melt electrolysis of the FeS-Na2S system with the production of iron was carried out. Thus the possibility of transformation of the nature of conductivity of highly conductive chalcogenide melts of iron towards their electrolytic ability is proved. The obtained results must be taken into account when using electrochemical technology of processing polymetallic sulfide ores, which include metal chalcogenides of iron family. KEYWORDS: MELTS, IRON CHALCOGENIDES, NATURE OF CONDUCTIVITY, ELECTRIC CONDUCTIVITY, TRANSFORMATION, ELECTROLYTIC CAPACITY.

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