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1.
Polyaniline (PANI) nanotubes were prepared by oxidation of aniline in 0.4 M acetic acid. They were subsequently used as a
reductant of silver nitrate in 1 M nitric acid, water or 1 M ammonium hydroxide at various molar ratios of silver nitrate
to PANI. The resulting PANI-silver composites contained silver nanoparticles of 40–60 nm size along with macroscopic silver
flakes. Under these experimental conditions, silver was always produced outside the PANI nanotubes. Changes in the molecular
structure of PANI were analyzed by FTIR spectroscopy. Silver content in the composites was determined as a residue by thermogravimetric
analysis, and confirmed by density measurements. The highest conductivity of a composite, 68.5 S cm−1, was obtained at the nitrate to PANI molar ratio of 0.67 in water. Also, the best reaction yield was obtained in water. Reductions
performed in an acidic medium gave products with conductivity of 10−4–10−2 S cm−1, whereas the reaction in alkaline solution yielded non-conducting products. 相似文献
2.
Martin Stěnička Vladimír Pavlínek Petr Sáha Natalia V. Blinova Jaroslav Stejskal Otakar Quadrat 《Colloid and polymer science》2008,286(12):1403-1409
The formation of chain structures by polarized polyaniline (PANI) particles suspended in silicone oil in the electric field
has been monitored by recording suspension conductivity in the course of time. For that purpose, three types of PANI particles
differing in the conductivity (3.1 × 10−3, 1.7 × 10−1, and 2.0 × 10−1 S cm−1) have been chosen out of a series of nine samples prepared by controlled protonation of PANI base in orthophosphoric acid
solutions. Relaxation times reflecting this process and characterizing the rate of the response to the electric field decreased
with particle conductivity, indicating a higher polarizability of particles. At the same time, the maximum conductivity of
suspension increased as a consequence of the electric and shear forces acting on the particles. In the shear fields, shorter
relaxation times appeared than at rest. The simultaneous measurement of the shear stress confirmed that the conductivity investigation
can reliably characterize the development of electrorheological structures. 相似文献
3.
Electrically conducting fibers based on coconut fibers (CF) and polyaniline (PANI) were prepared through in situ oxidative polymerization of aniline (ANI) in the presence of CF using iron (III) chloride hexahydrate (FeCl3.6H2O) or ammonium persulfate (APS) as an oxidant. The PANI-coated coconut fibers (CF-PANI) displayed various morphologies, electrical conductivities and percentages of PANI on the CF surface. For both systems, a PANI conductive layer was present on the CF surface, which was responsible for an electrical conductivity of around 1.5 × 10−1 and 1.9 × 10−2 S cm−1 for composites prepared with FeCl3.6H2O and APS, respectively; values that are similar to that of pure PANI. In order to modify the structure and properties of polyurethane derived from castor oil (PU) both CF-PANI and pure PANI were used as conductive additives. The PU/CF-PANI composites exhibited higher electrical conductivity than pure PU and PU/PANI blends. Additionally, the PU/CF-PANI composites showed a variation in electrical resistivity according to the compressive stress applied, indicating that these materials could be applied for pressure-sensitive applications. 相似文献
4.
O. A. Smirnova A. M. Mikhailova A. G. Yashin M. A. Chernova 《Russian Journal of Electrochemistry》2009,45(12):1393-1396
This work presents the results of a study of acrylic copolymer films from aqueous and nonaqueous media. Films prepared from
aqueous emulsions possess good physico-mechanical properties, are optically transparent, and are chemically resistant to concentrated
solutions of acids and bases. They may also be safely heated to a temperature of 333 K. Charge transport occurs through ion
exchange, and film conductivity is 1 × 10−3 S cm−1 at 298 K and 50% humidity. Acrylic copolymer films prepared from nonaqueous media (toluene, benzene, isopropyl acetate) exhibit
a conductivity of 5 × 10−3 S cm−1 at 298 K and 50% humidity, and modifying agents can be added to increase conductivity to 5 × 10−2 S cm−1. 相似文献
5.
Vandana A. Mooss Abhijit A. Bhopale Pravin P. Deshpande Anjali A. Athawale 《Chemical Papers》2017,71(8):1515-1528
In the present work, a set of polyaniline–graphene oxide (PANI–GO) nanocomposites which exhibit superior properties in terms of shelf life, processability and conductivity due to the synergistic effect of GO and PANI, have been synthesized by varying the concentration of highly non-conducting GO with respect to aniline. The obtained materials were characterized by UV–Vis, FTIR, XRD, Raman, TGA as well as FESEM, TEM analysis. The results reveal that nanocomposites show better dispersibility, crystallinity, thermal stability, and conductivity. Further, the synthesized composites have been tested for their anti-corrosion properties. The potentiodynamic results reveal that PANI nanocomposites with 1% GO exhibited long-term anti-corrosion behavior with a corrosion rate of 6.5 × 10?5 mm year?1, which is much lower than its individual components and commercial-grade red oxide. Also, it possesses highest impedance modulus ~33 kΩ cm2 and real impedance ~32 kΩ cm2, maximum coating resistance ~14.81 × 103 Ω cm2 and minimum coating capacitance after 96 h of immersion in 3.5% mass NaCl than those exhibited by all other coated samples. Higher concentration of GO could not retard the corrosion rate confirming that hydrophilicity of GO play an important role in the redox mechanism of PANI. 相似文献
6.
T. M. W. J. Bandara B.-E. Mellander I. Albinsson M. A. K. L. Dissanayake H. M. J. C. Pitawala 《Journal of Solid State Electrochemistry》2009,13(8):1227-1232
The anion-conducting polymer electrolyte polyethylene oxide (PEO)/ethylene carbonate (EC)/Pr4N+I−/I2 is a candidate material for fabricating photo-electrochemical (PEC) solar cells. Relatively high ionic conductivity values
are obtained for the plasticized electrolytes; at room temperature, the conductivity increases from 7.6 × 10−9 to 9.5 × 10−5 S cm−1 when the amount of EC plasticizer increases from 0% to 50% by weight. An abrupt conductivity enhancement occurs at the melting
of the polymer; above the melting temperature, the conductivity can reach values of the order of 10−3 S cm−1. The melting temperature decreases from 66.1 to 45.1 °C when the EC mass fraction is increased from 0% to 50%, and there
is a corresponding reduction in the glass transition temperature from −57.6 to −70.9 °C with the incorporation of the plasticizer.
The static dielectric constant values, , increase with the mass fraction of plasticizer, from 3.3 for the unplasticized sample to 17.5 for the 50% EC sample. The
dielectric results show only small traces of ion-pair relaxations, indicating that the amount of ion association is low. Thus,
the iodide ion is well dissociated, and despite its large size and relatively low concentration in these samples, the iodide
ion to ether oxygen ratio is 1:68, a relatively efficient charge carrier. A further enhancement of the ionic conductivity,
especially at lower temperatures, is however desired for these applications. 相似文献
7.
The effect of partial substitution of Zr4+ ions for Ge4+ ions in highly conducting lithium-cationic solid electrolyte Li3.75Ge0.75P0.25O4 is studied. It is found that the introduction of zirconium ions considerably raises the conductivity of basic electrolyte
in the high-temperature range. For the optimal composition, the conductivity is 2.82 × 10−1 S cm−1 at 400°C and 1.55 S cm−1 at 700°C. Possible reasons for the effects are discussed. 相似文献
8.
The use of high-voltage electroaccumulation in the determination of silver by stripping voltammetry at a mechanically renewed
graphite electrode with an area of 2.5 × 10−3 cm2 in 0.2% boric acid acidified with acetic acid at a voltage of 400 V and at an accumulation time of 5 min lowered the detection
limit for silver to 1 × 10−12 M. 相似文献
9.
E. I. Burmakin E. I. Volegova G. Sh. Shekhtman 《Russian Journal of Electrochemistry》2010,46(11):1323-1327
New solid rubidium-conducting electrolytes based on rubidium monoferrite in the system of Rb2 − 2x
Fe2−x
V
x
O4 are synthesized and studied. It is found that introduction of V5+ ions causes a drastic decrease in the electronic conductivity component prevalent in pure RbFeO2 with a simultaneous increase in the ionic conductivity. The latter becomes predominant at an increase in the concentration
of vanadium. The optimum compositions of the studied electrolytes feature a very high cationic rubidium conductivity (∼1.8
× 10−2 S cm−1 at 200°C, more than 10−1 S cm−1 at 700°C). The results are compared with the data obtained earlier for similar systems based on RbGaO2 and RbAlO2. 相似文献
10.
T. M. Wijendra Jayalath Bandara Piyasiri Ekanayake M. A. K. Lakshman Dissanayake Ingvar Albinsson Bengt-Erik Mellander 《Journal of Solid State Electrochemistry》2010,14(7):1221-1226
Various iodide ion conducting polymer electrolytes have been studied as candidate materials for fabricating photoelectrochemical
(PEC) solar cells and energy storage devices. In this study, enhanced ionic conductivity values were obtained for the ionic
liquid tetrahexylammonium iodide containing polyethylene oxide (PEO)-based plasticized electrolytes. The analysis of thermal
properties revealed the existence of two phases in the electrolyte, and the conductivity measurements showed a marked conductivity
enhancement during the melting of the plasticizer-rich phase of the electrolyte. Annealed electrolyte samples showed better
conductivity than nonannealed samples, revealing the existence of hysteresis. The optimum conductivity was shown for the electrolytes
with PEO:salt = 100:15 mass ratio, and this sample exhibited the minimum glass transition temperature of 72.2 °C. For this
optimum PEO to salt ratio, the conductivity of nonannealed electrolyte was 4.4 × 10−4 S cm−1 and that of the annealed sample was 4.6 × 10−4 S cm−1 at 30 °C. An all solid PEC solar cell was fabricated using this annealed electrolyte. The short circuit current density (I
SC), the open circuit voltage (V
OC), and the power conversion efficiency of the cell are 0.63 mA cm−2, 0.76 V, and 0.47% under the irradiation of 600 W m−2 light. 相似文献
11.
Budimir Marjanović Ivan Juranić Slavko Mentus Gordana Ćirić-Marjanović Petr Holler 《Chemical Papers》2010,64(6):783-790
Anilinium 5-sulfosalicylate was prepared and characterized by elemental analysis, and FTIR and NMR spectroscopies. It was
polymerized in an aqueous solution using ammonium peroxydisulfate as an oxidant. The precipitated polyaniline 5-sulfosalicylate
exhibited high thermal stability and conductivity of 0.13 S cm−1. Its mass-average molar mass and polydispersity index were determined by gel-permeation chromatography as 22,900 g mol−1 and 2.7, respectively. Elemental analysis and FTIR spectroscopy study of polyaniline 5-sulfosalicylate revealed the doping
level and the oxidation state between emeraldine and protoemeraldine salt while corresponding studies of the polyaniline base
indicate a small extent of the covalent bonding of 5-sulfosalicylate anions to polyaniline chains. 相似文献
12.
Polyaniline (PANI) base has been suspended in 9 M potassium hydroxide at 20 °C or 90 °C for various time intervals extending to 4 months. The fraction of acetone-soluble material increased from 1.2 wt.% to 4.5 wt.% after exposure to an alkaline medium for 60 days at 20 °C. Gel-permeation chromatography indicates that the aggregation of PANI is reduced, while the chain degradation itself is negligible. FTIR spectroscopy confirms this trend and the absence of hydrolytic changes in the PANI structure. Polyaniline retains the ability to be reprotonated with a 1 M sulfuric acid to a conducting form. No marked changes in the molecular structure have been found, even after suspension of PANI in 9 M KOH at 90 °C for 60 days.Similar immersion of PANI salt in 5 M sulfuric acid at 20 °C was responsible for changes in the protonation, and the mass increased by 11 wt.%. This was explained by the exchange of the original sulfate or chloride counter-ions for hydrogen sulfate anions or by the protonation of secondary amine sites in PANI in addition to imine ones. The changes in the molecular structure are discussed on the basis of FTIR spectra. The conductivity decreased from 1.2 S cm−1 to ∼10−3 S cm−1 but no time-dependence of conductivity was observed. There was no fraction of PANI soluble in acetone. PANI in the protonated state is thus stable also in the strongly acidic medium.The study is supplemented by the assessment of the thermal stability of PANI base, which is of importance for the processing of PANI. Loss of moisture has been observed after exposure to 250 °C for 10 h in both nitrogen atmosphere and in air. Good stability was found at 350 °C only in the nitrogen atmosphere, while a marked mass loss in weight was registered in air. 相似文献
13.
G. Sh. Shekhtman E. I. Volegova E. I. Burmakin 《Russian Journal of Electrochemistry》2009,45(4):465-469
RbAlO2-based solid solutions are synthesized in the systems Rb2 − x
Al2 − x
A
x
O4 (A = P, V). Temperature and concentration dependences of their conductance are studied; the rubidium-cationic character of
the conductance is corroborated. The high ionic conductivity of the synthesized phases (∼5 × 10−3 S cm−1 at 300°C, ∼2 × 10−2 S cm−1 at 700°C) is caused by (a) formation of rubidium vacancies as a result of the replacing of Al3+ ions by fivefold-charged cations of phosphorus or vanadium and (b) disordered crystal structure of γ-KAlO2 type. The obtained data are compared with the results of the studying of similar systems.
Original Russian Text ? G.Sh. Shekhtman, E.I. Volegova, E.I. Burmakin, 2009, published in Elektrokhimiya, 2009, Vol. 45, No.
4, pp. 495–499. 相似文献
14.
Electrical conductivity of some dibenzoylmethane arylhydrazones (DBMAH) were measured during heating and reheating runs. The
observed variation of the conductance of the polycrystalline sample during thermal agitation was found to depend on the ordering
and disordering of molecules which in turn cause the lattice dipole to distort. A semiconducting behavior was detected for
these systems as it was deduced from their conductance values (1.7 × 10−6 − 8.25 × 10−7 ohm−1 cm−1). The presence of substituents affects markedly the measured electrical conductivity and calculated activation energy values. 相似文献
15.
A simple, sensitive, and reliable method based on a combination of multi-walled carbon nanotubes with incorporated β-cyclodextrin
(β-CD-MWNTs) and a polyaniline (PANI) film-modified glassy-carbon (GC) electrode has been successfully developed for determination
of dopamine (DA) in the presence of ascorbic acid (AA). The PANI film had good anti-interference properties and long-term
stability, because of the permselective and protective properties of the conducting redox polymer film. The acid-treated MWNTs
with carboxylic acid functional groups promoted the electron-transfer reaction of DA and inhibited the voltammetric response
of AA. Sensitive detection of DA was further improved by the preconcentration effect of formation of a supramolecular complex
between β-CD and DA. The analytical response of the β-CD-MWNTs/PANI film to the electrochemical behavior of DA was, therefore,
better than that of a MWNTs/PANI film, a PANI film, or a bare glassy-carbon (GC) electrode. Under the conditions chosen a
linear calibration plot was obtained in the range 1.0 × 10−7–1.0 × 10−3 mol L−1 and the detection limit was 1.2 × 10−8 mol L−1. Interference from AA was effectively eliminated and the sensitivity, selectivity, stability, and reproducibility of the
electrodes was excellent for determination of DA. 相似文献
16.
I. K. Larin N. A. Messineva A. I. Spasskii E. M. Trofimova L. E. Turkin 《Kinetics and Catalysis》2000,41(4):437-443
The reactions of iodine monoxide (IO•) with sulfur-containing compounds, which are important for the atmospheric chemistry, are studied. An attempt is made to
distinguish between the heterogeneous and homogeneous reaction pathways. It is shown that, under the experimental conditions,
the reactions proceed on the wall and generate iodine atoms into the gas phase. It is found that, at room temperature, the
rate constants for the gas-phase reactions of IO• with (CH3)2S and H2S are lower than 2.5 × 10−14 and 8.0 × 10−14 cm3 molecule−1 s−1, respectively; the rate constant for the gas-phase reaction of iodine monoxide with SO2 ≤ 5.6 × 10−15 cm3 molecule−1 s−1. 相似文献
17.
B. A. Trofimov T. A. Skotheim A. G. Mal'kina L. V. Sokolyanskaya G. F. Myachina S. A. Korzhova E. S. Stoyanov I. P. Kovalev 《Russian Chemical Bulletin》2000,49(5):863-869
Polyethylene is exhaustively sulfurized by elemental sulfur at 160–365 °C to release hydrogen sulfide and form black lustrous
powders (sulfur content ≈80%) that possess electric conductivity (10−6–10−8 S cm−1 when doped with I2). Elemental analysis data, IR spectra, X-ray patterns, DSC-TGA. derivatographic data, electric conductivity, and mass spectrometric
characteristics of the polymers synthesized suggest the presence of fused polythienothiophene and polynaphthothienothiophene
blocks in the polymers.
For Part 1, see Ref. 1
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 865–871, May, 2000. 相似文献
18.
Poly(vinylferrocenium) perchlorate–polyaniline (PVF+–PANI) composite film was synthesized electrochemically on Pt electrode in a methylene chloride solution containing a mixture
of poly(vinylferrocene) (PVF) polymer and aniline monomer. PVF+ polymer in the composite film was used as an electron transfer mediator. The composite coating showed significant electrochemical
activity towards hydroquinone (HQ) at pH 4, with high sensitivity and a wide linearity range. The interaction of HQ with PVF+ and PANI homopolymer films was investigated electrochemically and spectroscopically. HQ molecules are accumulated on the
electrode surface due to trapping by both polymers in the composite film and then oxidized catalytically by PANI. The most
significant contribution of PVF+ polymer is that it facilitates electron transfer in the composite film. The linear response range was found to be between
1.60 × 10−4 mM and 115 mM (R
2 = 0.999) at 0.45 V vs saturated calomel electrode. The limit of detection (LOD) was 4.94 × 10−5 mM. 相似文献
19.
Yuzhong Zhang Guiying Jin Wangxing Cheng 《Journal of Solid State Electrochemistry》2006,10(4):260-263
The stable electroactive thin film of rhein has been investigated by cyclic voltammetry and electrochemical impedance spectroscopy.
Electrochemical impedance spectroscopy of the electrodeposited film derived from rhein indicated the electrode reaction was
kinetically controlled in the region of higher frequency, the charge transfer resistance was 2.6×103 Ω cm2 and capacitance value was 13.2 μF cm2 . The electrodeposited film derived from rhein exhibited a good electrocatalytic activity for myoglobin (Mb) reduction. In
0.30 mol dm−3 H2SO4solution, the catalysis currents were proportional to the concentrations of Mb over the range of 1.5×10−7–1.3×10−5 mol dm−3. The detection limit is 1.0×10−7 mol dm−3 (S/N=3). The relative standard deviation is 4.8% for eight successive determinations of 5.0×10−7 mol dm−3 Mb. 相似文献
20.
Jiawei Zhang Xiaobin Huang Hao Wei Jianwei Fu Yawen Huang Xiaozhen Tang 《Journal of Solid State Electrochemistry》2012,16(1):101-107
Solid composite polymer electrolytes consisting of polyethylene oxide (PEO), LiClO4, and porous inorganic–organic hybrid poly (cyclotriphosphazene-co-4, 4′-sulfonyldiphenol) (PZS) nanotubes were prepared using the solvent casting method. Differential scanning calorimetry
and scanning electron microscopy were used to determine the characteristics of the composite polymer electrolytes. The ionic
conductivity, lithium ion transference number, and electrochemical stability window can be enhanced after the addition of
PZS nanotubes. The electrochemical impedance showed that the conductivity was improved significantly. Maximum ionic conductivity
values of 1.5 × 10−5 S cm−1 at ambient temperature and 7.8 × 10−4 S cm−1 at 80 °C were obtained with 10 wt.% content of PZS nanotubes, and the lithium ion transference number was 0.35. The good
electrochemical properties of the solid-state composite polymer electrolytes suggested that the porous inorganic–organic hybrid
polyphosphazene nanotubes had a promising use as fillers in SPEs and the PEO10–LiClO4–PZS nanotube solid composite polymer electrolyte might be used as a candidate material for lithium polymer batteries. 相似文献