Papers by Keyword: Polyaniline (PANI)

Abstract: With an average diameter of 148-285 nm and a conductivity of 2.38E^-2- 5.88 E^-2S/cm, Nanoscaled polyaniline (PANI) were synthesized based on template-free method in the presence of dicarboxylic acids dopants (e.g., D-tartaric acid, Succinic acid, maleic acid and fumaric acid). Furthermore, the trans-cis isomerization of butenedioic acid plays an important role in the formation of nanostructures from plane-like to nanofibers, and PANI-MA has larger diameter, higher crystallinity and conductivity than PANI-FA.

Abstract: A nitrite sensor based on a gold particles/polyaniline modified glassy carbon electrode (Au/PAni/GCE) was devoped by electrochemical method. The electrocatalytic oxidation of nitrite at Au/PAni/GCE was studied by cyclic voltammetry. The experimental parameters were optimized, and a voltammetric method for determining nitrite was developed. In phosphate buffered solution(PBS) of pH 3.0, the oxidation peak current of nitrite is proportional to the concentration of nitrite over the range of 4.0×10^-7～5.0×10^-3mol/L with the detection limit of 2.0×10^-7mol/L (r=0.9992). The presented methods of determing nitrite exhibited high sensitivity and good reproducibility.

Abstract: Polythionphene (PTH)/polyaniline (PANI)/activated carbon (AC) composites as electrode materials for supercapacitors were synthesized by in-situ polymerization of thionphene on PANI/AC. The surface morphology and the molecular structure of the composites were examined by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The electrochemical performances were tested by cyclic voltammetry, Galvanostatic charge-discharge and electrochemical impedance spectrometry. Results show that the PTH/PANI/AC composites exhibit better large current charge-discharge performance and higher capacitance than those of PANI/AC. The capacitance value of the composites would reach 597.4 F/g. The PTH/PANI/AC composites also have better cycle stability than that of PANI/AC.

Abstract: In this article, the polyaniline(PANI) spherical nanoparticles were synthesized by the way of emulsion polymerization. The effects of emulsifier concentration on the morphology and electrical properties were systematic studied. The structure of PANI prepared by this method was characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM). The electrochemical and capacitive behavior of PANI prepared by this way was systematically studied by cyclic voltammetry(CV) and electrochemical impedance spectroscopy (EIS) tests. The results showed that we obtained PANI spherical nanoparticles with diameter about 100nm and it had good electrochemical performance.

Abstract: In presence of nano-In₂O₃ which were synthesised via a reverse microemulsion, Polyaniline/nano-In₂O₃ composites were prepared by in-situ polymerization of aniline in 5-sulphosalicylic acid(SSA) aqueous solution. They were characterized by means of TEM, XRD and FTIR.. TEM and XRD showed that the average diameter of In₂O₃ particles was 15nm with a narrow size distribution and with a high degree of crystallization. The FTIR suggested that the structure of PAn-SSA was not be changed by the mixture of In₂O₃. Sensitivity of the composites to 100~1000ppm NH₃ were studied, the results reveal that polyaniline/nano-In₂O₃ composites have short response time and good reversibility, the gas sensitive of composites to NH₃ under 300ppm increased linearly with the increasing concentration of NH₃ and decreased with the increasing of In₂O₃ concentration. Long-term stability of polyaniline/nano-In₂O₃ composites were also investagated, it can be concluded that the organic-inorganic hybrid materials have better environmental stability.

Abstract: In recent years, conductive paper produced by in-situ chemical polymerization of pyrrole and aniline in aqueous electrolytes has aroused a great interest. The in-situ chemical polymerization process is a process in which a monomer such as aniline or pyrrole is polymerized in the presence of pulp fibers. This approach can not only impart to paper specific functions, but also provide a new possibility for the processing and utilization of conductive polymers. In this paper, the research progress on inherently conducting polymer coated paper was overviewed.

Abstract: Polyaniline nanoparticle was synthesized via the chemical oxidation of aniline with ammonium persulphate in aqueous hydrochloric acid where the polyaniline particle size obtained was in the range of 22-53 nm. Polyaniline is one type of conducting polymers, where this polymer exhibit high electrical conductivity and have a wide range of interesting application due to its light weight, conductivity and chemical properties. Amongst the family of conducting polymers, polyaniline is unique due to ease of synthesis, environmental stability, simple doping/dedoping chemistry and relatively inexpensive cost. Polyaniline has been used to improve hydrophilic property and permeability of substrate membrane. It is used to obtain superhydrophilic surface because of their high surface energy and hydrophilic property. In this research, these nanoparticles have been used to improve hydrophilic property and permeability of polyethersulfone membrane. The blended membrane was characterized using pure water flux, Scanning Electron Microscope (SEM), and contact angle. As a result, polyaniline can distribute stably in polyaniline membrane to produce stable structure and preferable performance.

Abstract: Intrinsically conductive polymer-Polyaniline had high conductivity and many other properties, such as environmental stability and rather simple synthesis. In addition, doping with organic acids could enhance its processing, so it had wide range of applications, such as solar cells, antistatic and electromagnetic interference shielding. In this study, the organic amine 1-Dodecylamine (DOA) modification of sodium montmorillonite (NA+-MMT), and conducting polymer / layered silicate salt nanocomposites (PANI-PTSA/DOA-MMT) had been prepared by doping aniline with organic acid (PTSA), then added organic clay. The thermal, electrical properties and EMI effects of nanocomposites had discussed by XRD, TEM, EMI, TGA analysis, conduction measure and EMI tested. The results indicated the organo-clay interlayer distance expanded from 1.29 to 1.8 nm, and DOA-MMT dispersed in the material, that formed an exfoliated nanocomposite. The thermal stability of nanocomposites depended on content of DOA-MMT, material had the better thermal stability when DOA-MMT load was 5 wt. %. The nanocomposites had the best conductivity when DOA-MMT load was 1 wt. % as well as the electromagnetic shielding effectiveness was increase with increase in conductivity. In addition, the electromagnetic shielding of nanocomposites also depended on thickness and frequency of electromagnetic wave, the electromagnetic shielding was increased with increase in thickness and frequency.

Abstract: Four polyaniline hybrid materials were prepared by liquid-state synthesis method in the presence of dopant which synthesized by transition metal mono-substituted Keggin structure silicotungstate anions α, βi-[SiW11Ga(H2O)O39]4-. The polyaniline hybrid materials were characterized by elemental analysis, IR spectroscopy, fluorescence spectroscopy, scanning electeon microscopy (SEM) and thermo gravimetric analysis, the properties of which such as thermal stability and conducting behavior were studied. It proved that the average diameter was 100nm, the conductivity was 9×10-2s•cm-1 and the flourescence property was better.

Abstract: Conductive polyaniline/zirconia (PANI/ZrO2) composites have been synthesized by in-situ polymerization of aniline in the presence of ZrO2 nanoparticles. The structure and morph- ology of composites were characterized by Fourier-transform infrared spectra (FTIR), thermo- gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscope (SEM). The conductivity was also investigated. The results showed that PANI and ZrO2 nanoparticles were not simply blended, and a strong interaction existed at the interface of ZrO2 and PANI. It was probably a composite at molecular level. The composites were more thermal stability than that of the pure PANI. XRD analyses confirmed PANI deposited on the surface of ZrO2 nanoparticles had no effect on crystallization performance of ZrO2 nanoparticles. Electrical conductivity measurements indicated that the conductivity of PANI/ZrO2 composites was much higher than that of PANI and the maximum conductivity obtained was 11.27S/cm at 15 wt% of ZrO2 nanoparticles.