• KSTLE International Journal
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• v.7 no.1
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• pp.18-21
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• 2006

The electrorheology of hollow PANI derivative suspensions in silicone oil was investigated by varying the electric fields and shear rates, respectively. The hollow PANI derivative susepnsions showed a typical electrorheological (ER) response caused by the polarizability of an amide polar group and shear yield stress due to the formation of chains upon application of an electric field. The shear stress for the hollow PANI succinate suspension exhibited an electric field power of 0.67. On the basis of the experimental results, the newly synthesized hollow PANI derivative suspensions were found to be an anhydrous ER fluid.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.334-336
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• 2003

Polyaniline(PANi) composite panicles were synthesized by chemical oxidation polymerization of aniline in presence of Poly-N-Isopropyl acryl amide(PNIPAM). The PANi panicles are formed in the reaction medium deposited onto non-conducting PNIPAM template to produce PANi-coated composite panicles. The formation of composite was confirmed by FT-IR spectroscopy, and UV-VIS spectroscopy, and their morphological structures were examined by scanning electron microscopy(SEM). From the experimental results, it was determined that PANi was successfully coated onto non-conducting PANIPAM.

• Journal of the Korean Applied Science and Technology
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• v.32 no.1
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• pp.85-92
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• 2015

The 50 mole% HCl doped polyaniline(PAni) was synthesized by polymerization of aniline in the presence of hydrochloric acid and ammonium persulfate(APS) as dopant and oxidant, respectively. Then, conducting biodegradable cellulose acetate composite films were also prepared with PAni in acetone to find their applicability to antistatic packaging materials. The tensile strength of PCA05 film with 5 wt% of PAni was decreased by 27% from $377.1kg_f/cm^2$ for CA film itself to $275.2kg_f/cm^2$. Elongation was also decreased from 7.65% to 4.35%. Surface registance of $7.0{\times}10^9{\Omega}/sq$ could be achieved for the PCA containing 5 wt% of PAni. Therefore, this PCA05 film can be applied to antistatic package film for electronic board. In addition, decomposition temperature of these PCA films obtained by thermogravimetric analysis(TGA) was decreased with the amount of PAni in PCA films, and the final weight of char was directly proportional to PAni contents. From this thermal result we can calculate the content of PAni in unknown PCA films.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1799-1805
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• 2014

In this article, we described about the preparation and electrochemical properties of a flexible energy storage system based on a plastic polyethylene terephthalate (PET) substrate. The PET treated with UV/ozone was fabricated with multilayer films composed of 30 polyaniline (PANi)/graphene oxide (GO) bilayers using layer-by-layer assembly of positively charged PANi and negatively charged GO. The conversion of GO to the reduced graphene oxide (RGO) in the multilayer film was achieved using hydroiodic acid vapor at $100^{\circ}C$, whereby PANi structure remained nearly unchanged except a little reduction of doping state. Cyclic voltammetry and charge/discharge curves of 30 PANi/RGO bilayers on PET substrate (shorten to PANi-$RGO_{30}$/PET) exhibited an excellent volumetric capacitance, good cycling stability, and rapid charge/discharge rates despite no use of any metal current collectors. The specific capacitance from charge/discharge curve of the PANi-$RGO_{30}$/PET electrode was found to be $529F/cm^3$ at a current density of $3A/cm^3$, which is one of the best values yet achieved among carbon-based materials including conducting polymers. Furthermore, the intrinsic electrical resistance of the PANi-$RGO_{30}$/PET electrodes varied within 20% range during 200 bending cycles at a fixed bend radius of 2.2 mm, indicating the increase in their flexibility by a factor of 225 compared with the ITO/PET electrode.

• Korean Chemical Engineering Research
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• v.56 no.6
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• pp.884-889
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• 2018

In this study, polyaniline $(PANI)/WO_3$ electrode was prepared as an anode of a lithium ion capacitor, and its electrochemical characteristics were measured and analyzed. When PANI was electrochemically deposited on the surface of $WO_3$ electrode, the capacity of $PANI/WO_3$ was improved with increase of the deposited amounts of PANI. Furthermore, the effect of light irradiation on capacity and coulombic efficiency was examined by irradiating sunlight during charging and discharging. When the light was irradiated to the $WO_3$ electrode and the $PANI/WO_3$ electrode, those capacities and coulombic efficiencies were increased compared to that measured under the dark condition. It is attributed to the photocatalytic property of $WO_3$ that can generate photoelectrons by light irradiation. In $PANI/WO_3$ electrode, PANI also can be excited under the light irradiation with affecting the electrochemical property of electrode. The photoelectrons improve the capacity by participating in the intercalation of $Li^+$ ions, and also improve the coulombic efficiency by facilitating electrons' transport. Under the dark condition, the capacity of $PANI/WO_3$ was gradually reduced with increase of cycles due to a poor stability of PANI. However, the stability of PANI was significantly improved by the light irradiation, which is attributed to the oxidation-reduction reaction originated from the photogenerated electrons and holes in $PANI/WO_3$.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.196-201
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• 2023

In this study, a CNT fiber flexible electrode grafted with CuO nanoparticles (CuO NPs) and polyaniline (PANI) was developed and applied to a nonenzymatic electrochemical sensor for H₂O₂ detection. CuO NPs/PANI/CNT fiber electrode was fabricated through the synthesis and deposition of PANI and CuO NPs on the CNT fiber surface using an electrochemical method. Surface morphology and elemental composition of the CuO NPs/PANI/CNT fiber electrode were characterized by scanning electron microscope with energy dispersive X-ray spectrometry. And its electrochemical characteristics were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Compared with a bare CNT fiber as a control group, the CuO NPs/PANI/CNT fiber electrode showed a 4.78-fold increase in effective surface area and a 8.33-fold decrease in electron transfer resistance, which leads to excellent electrochemical properties such as a good electrical conductivity and an efficient electron transfer. These improved characteristics were due to the synergistic effect through the grafting of CNT fiber, PANI and CuO NPs. As a result, this electrode enhanced the H₂O₂ sensing performance.

• Membrane Journal
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• v.13 no.3
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• pp.162-173
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• 2003

The pseudo n-type polyaniline was prepared by doping of camphorsulfonic acid(CSA) and dodecylbenzenesulfonic acid(DBSA) as the dopants in solvent of N-methyl-2-pyrrolidinone(NMP). The dopants in polymer structure was qualitatively analyzed using FT-IR. The influence on electrochemical properties with dopant concentration of PANI film were investigated. The electrochemical characteristics of the n-type PANI electrode that coated on ITO were evaluated by cyclic voltammetry(CV) and AC impedance method. The prepared PANI were confirmed as n-type PANI from FT-IR and CV. The charge transfer resistance of film on PANI/CSA electrode were measured as 1.14{\sim}1.09k{\mu}$by AC impedance. The charge transfer resistance of PANI/DBSA electrode decreased with increasing the mole ratio of DBSA as 27.73{\sim}8.37 k{\mu}$. The double layer capacitance of PANI/CSA electrode was showed almost constant value as $13.47{\sim}14.59 {\mu}F$ and that of PANI/DBSA electrode increased with increasing mole ratio of DBSA from 0.49 to $1.20 {\mu}F$.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.220-220
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• 2012

The supercapacitors with extraordinarily high capability for energy storage are attracting growing attention for their potential applications in portable electronic equipments, hybrid vehicles, cellular devices, and so on. The nanostructuring of the electrode surface can provide large surface area and consequently easy diffusion of ions in the capacitors. In addition, compared to two-dimensional nanostructures, the three-dimensional (3D) nano-architecture is expected to lead to significant enhancement of mechanical and electrical properties such as capacitance per unit area of the electrode. Polyaniline (PANi) is known as promising electrode material for supercapacitors due to its desirable properties such as high electro activity, high doping level and environmental stability. In this context, we fabricated well-ordered 3D PANi nanostructures on 3D polystyrene (PS) nanospheres which was arrayed by layer-by-layer stacking method. The height of the PANi nanostructures could be controlled by the number of PS layers stacked. 3D PANi hollow nanospheres were also fabricated by dissolving inner PS nanospheres, which resulted in further enhancement of the surface area and capacitance of the electrode.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2111-2116
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• 2013

This paper reports substituent effects on the conformational changes in polyaniline (PAni) derivatives. PAni, poly-o-toluidine (POT), and poly-o-anisidine (POA) were formed by potentiodynamic electropolymerization in aqueous solution containing (+)-camphorsulfonic acid (CSA) as a dopant. UV-Vis spectroscopy and cyclic voltammetry measurements revealed that the methyl group showed a greater steric hindrance than the methoxy group. Further, the doping level decreased with increasing steric hindrance. The sign pattern of the circular dichroism (CD) bands for POA was opposite to that for PAni. However, no CD bands were observed in POT. The steric hindrance caused helical inversion, but at a high level of steric hindrance, the helical conformation could not be adopted, because of the reduced doping level. The reduced crystallinity was greatly affected by the decreased doping level. The steric effect influenced the polymer conformation and the doping level, thus determining the optical activity, morphology, and crystallinity of the PAni derivatives.

• Korean Journal of Materials Research
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• v.14 no.4
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• pp.260-264
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• 2004

The problem of polyaniline (PANi) sensor has been poor mechanical and chemical stability under atmosphere condition. In order to overcome these problems, the PANi sensor coated with polyvinylidenefluoride ($PVF_2$) was employed. The morphology of $PVF_2$ coated-PANi layer was showed smooth and transparent properties at 15% concentration of coating solution. The resistance of $PVF_2$ coated-PANi was kept at constant value and had a good stability at long-term periods in presence of humidity.