EFFECT OF PRIMARY DOPANTS ON THE CONDUCTIVITY OF POLYANILINE SYNTHESIZED BY ELECTROCHEMICAL POLYMERIZATION (original) (raw)
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Conductive polymer as Polyaniline (PANI-ES) prepared by chemical oxidation polymerization method at room temperature and studied the effect the dopant sulfuric acid on the structure of the polymer, which prepared with molarity of sulfuric acid (1M), the changes taking place were follow-up by the following measurements: FESEM, FT-IR, I-V character. The diagnosis of the output polymer films by using infrared spectroscopy FT-IR, for doped samples with 1M of sulfuric acid observed change in the intensity of emission opposite the wave number corresponding to each bond, while not noticed any change in the position of the bonds with appearance anew peak return to SO 4 compound. By the FESEM properties of the surface study using the topography FESEM (Field Emission Scanning Electronic Microscopic) and calculated the particle revealed, that the compound has micro granular affected with the presence of acid. Electrical characteristic study by using the two-probe manner, it found that the samples had ohmic plots in which high linear coefficients. The doped samples of polymer had a highest conductivity of 2.98x10-4 S.cm-1 at 383 K, which observed for the H 2 SO 4 doped sample, which shows that was more prominent of localized salt in polymer.
Effects of Dopant Ions on the Properties of Polyaniline Conducting Polymer
ORIENTAL JOURNAL OF CHEMISTRY, 2018
This work will show, for the frst time, the effect of nicotinic acid (NA) and 2-methylnicotinic acid (MNA)on the synthesis and properties of conducting polyaniline (PANI). The work investigates the effects of sulphuric acid (H2SO4), nicotinic acid (NA), and 2-methylnicotinic acid (MNA) on the synthesis and properties of polyaniline. The results show that the preparation of polyaniline from a sulphuric acid electrolyte is faster than the preparation from nicotinic acid and 2- methylnicotinic acid electrolytes. Moreover, the electrical conductivity and thermal stability of PANI/H2SO4 were greater than PANI/NA and PANI/MNA. All the polymers prepared in this study were identifed using FT-IR. Scanning electron microscopy (SEM) was used to examine the morphologies of the PANI samples, from which it was determined that PANI/H2SO4 has a fbrous and open structure with a higher porosity morphology compared to PANI/NA and PANI/MNA. The electrical conductivities of the PANI samples were measured as 1.09 S cm-1, 0.65 S cm-1 and 0.089 S cm-1 for PANI/H2SO4, PANI/NA and PANI/MNA, respectively. The thermal stability of PANI was examined using the Thermogravimetric Analysis (TGA) technique. PANI/H2SO4 was found to degrade between 450-500°C, while PANI/NA and PANI/MNA decomposed at temperatures between 300-400°C.
The International Journal of Science & Technoledge, 2020
This article reports the synthesis of Polyaniline (PANI) in emeraldine form (EB) by in-situ chemical oxidation method using different dopants and ammonium persulphate (APS) as an oxidant. The samples were characterized by FTIR, UV-Vis, and their conductivity determined by four-point probe method. Quinoid and benzenoid bands at 1553-1596 cm-1 and 1437-1496 cm-1 respectively where observed in all the samples. The band gaps and conductivity values for all the bulk samples were obtained using the absorption spectra and Stern relation. It was found that the transition π i-iπ* iforiPANI-H2SO4 ioccurs iearlier ithan iin iPANI-HCl isample.i This ican ionly ibe ias ia iresult iof ithe iH2SO4 iacid ibeen ia istronger iacid ithan ithe iHCl iand ias ia iresult ithe itransition ifrom iπ i-iπ* irequired ilower swavelength ifor iPANI-H2SO4 isample ias icompared ito ithe iPANI-HCl isample.iBy icomparing ithe ifour isamples ithe iπ i-iπ* itransition ithen ican ibe iarranged ifrom ithe istrongest ito ithe iweakest ias iPANI-H2SO4 ifollowed iby iPANI-HCl ithen iPANI-HNO3 iand ithe iweakest ibeing iPANI-CH3COOH. The same trend is also observed for electrical conductivity of these samples.
The present work reports the chemical oxidation synthesis of polyaniline using ammonium persulphate (APS) as an oxidizing agent and H 2 SO 4 , HCl and CH 3 COOH as dopants. The samples were characterized by FTIR, UV-Vis, and their conductivity determined by four-point probe method. Quinoid and benzenoid bands at 1553-1596 cm-1 and 1437-1496 cm-1 respectively where observed in all the samples. Different transitions present in the bulk samples of PANI were determined by UV-VIS spectroscopy. It was found that the transition π i-iπ* iforiPANI-H 2 SO 4 i occurs iearlier ithan iin iPANI-HCl isample.iThis ican ionly ibe ias ia iresults iof ithe iH 2 SO 4 i acid ibeen ia istronger iacid ithan ithe iHCl iand ias ia iresults ithe itransition ifrom iπ i-iπ* irequired ilower swavelength ifor iPANI-H 2 SO 4 i sample ias icompared ito ithe iPANI-HCl isample.iBy icomparing ithe ifour isamples ithe iπ i-iπ* itransition ithen ican ibe iarranged ifrom ithe istrongest ito ithe iweakest ias iPANI-H 2 SO 4 i followed iby iPANI-HCl ithen iPANI-HNO 3 i and ithe iweakest ibeen iPANI-CH 3 COOH that also show the trend of observed conductivities in these samples.
The present work reports the chemical oxidation synthesis of polyaniline using ammonium persulphate (APS) as an oxidizing agent and H 2 SO 4 , HCl and CH 3 COOH as dopants. The samples were characterized by FTIR, UV-Vis, and their conductivity determined by four-point probe method. Quinoid and benzenoid bands at 1553-1596 cm -1 and 1437 -1496 cm -1 respectively where observed in all the samples. Different transitions present in the bulk samples of PANI were determined by UV-VIS spectroscopy. It was found that the transition π i-iπ* iforiPANI-H 2 SO 4 i occurs iearlier ithan iin iPANI-HCl isample.iThis ican ionly ibe ias ia iresults iof ithe iH 2 SO 4 i acid ibeen ia istronger iacid ithan ithe iHCl iand ias ia iresults ithe itransition ifrom iπ iiπ* irequired ilower swavelength ifor iPANI-H 2 SO 4 i sample ias icompared ito ithe iPANI-HCl isample.iBy icomparing ithe ifour isamples ithe iπ i-iπ* itransition ithen ican ibe iarranged ifrom ithe istrongest ito ithe iweakest ias iPANI-H 2 SO 4 i followed iby iPANI-HCl ithen iPANI-HNO 3 i and ithe iweakest ibeen iPANI-CH 3 COOH that also show the trend of observed conductivities in these samples.
This article reports the synthesis of Polyaniline (PANI) in emeraldine form (EB) by in-situ chemical oxidation method using different dopants and ammonium persulphate (APS) as an oxidant. The samples were characterized by FTIR, UV-Vis, and their conductivity determined by four-point probe method. Quinoid and benzenoid bands at 1553-1596 cm-1 and 1437-1496 cm-1 respectively where observed in all the samples. The band gaps and conductivity values for all the bulk samples were obtained using the absorption spectra and Stern relation. It was found that the transition π i-iπ* iforiPANI-H2SO4 ioccurs iearlier ithan iin iPANI-HCl isample.i This ican ionly ibe ias ia iresult iof ithe iH2SO4 iacid ibeen ia istronger iacid ithan ithe iHCl iand ias ia iresult ithe itransition ifrom iπ i-iπ* irequired ilower swavelength ifor iPANI-H2SO4 isample ias icompared ito ithe iPANI-HCl isample.iBy icomparing ithe ifour isamples ithe iπ i-iπ* itransition ithen ican ibe iarranged ifrom ithe istrongest ito ithe iweakest ias iPANI-H2SO4 ifollowed iby iPANI-HCl ithen iPANI-HNO3 iand ithe iweakest ibeing iPANI-CH3COOH. The same trend is also observed for electrical conductivity of these samples.
PANI Conductivity: A Dependence of the Chemical Synthesis Temperature
This work evaluated the influence of the synthesis temperature on the polyaniline (PANI) properties obtained by in-situ polymerization onto a poly (terephthalate) (PET) substrate. The residual mass of these syntheses was dried under vacuum, obtaining PANI powders for each temperature investigated. PANI/PET thin films and PANI powders were characterized by atomic force microscopy (AFM), field emission scanning electron microscopy (FEG-SEM), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis) and four-point probe techniques. The UV-Vis results showed that the synthesized PANI presents the emeraldine oxidation state. By means of XRD technique, it was possible to verify that the PANI powders present crystalline form. The AFM and FEG-SEM techniques showed that the decrease in PANI/PET and PANI powders electrical conductivity with increasing of the synthesis temperature is related to the polymeric aggregates morphology.
A Study on The Conductivity of Polyaniline Polymers
IOP Conference Series: Materials Science and Engineering
Polyaniline (PANI) is a promising conducting material to be used in a variety of electronic applications ranging from sensors, through solar cells to touch screens. Enhancing the electrical characteristics of polyaniline by increasing the charge carriers, using doping materials, allows for using it as a good alternative for semiconductors in the fabrication of integrated circuits. Zinc sulfide (Zns) is considered one of the attractive doping materials that improve the electrical characteristics of polyaniline owing to the distinctive optical characteristics in the visible range. In this work, a practical study on the electrical properties of polyaniline doped with zinc sulfide is presented and compared with pure PANI. Different volume rates of doping are tested, experimentally, and the results are collected. Voltage-current characteristics and the activation energy levels are obtained for different temperatures. From the results, it has been observed that the conductivity increases by increasing the doping rate and inversely related to temperature. A low activation energy level and improved I-V characteristics are shown to be approachable by careful choice of doping rate. Polyaniline doped with zinc sulfide provides low cost conductors for integrated circuits industry.
Materials Letters, 2002
An attempt has been made to prepare polyaniline (PA), poly(o-toluidine) (POT) and copolymer (PA-POT) thin films doped by several inorganic salts (sulphates and chlorides) with varying size of cation using aqueous solution of H 2 SO 4 as electrolyte. Effect of dopant in presence of electrolyte is rarely studied in the field of conducting polymers. Various inorganic salts as dopants, viz. K 2 SO 4 , Na 2 SO 4 , Li 2 SO 4 , MgSO 4 , KCl, NaCl, LiCl and MgCl 2 are used at room temperature. The films were electropolymerized in solution containing 0.1 M monomer, 1 M H 2 SO 4 as electrolyte and 1 M inorganic salt by applying sequential linear potential scan rate 50 mV/s between À 0.2 and 1.0 V versus Ag/AgCl electrode. The electrosynthesized films were characterized by cyclic voltammetry, UV-visible spectroscopy and conductivity measurements using four-probe technique. It was observed that the UV-visible peaks are appearing at about 800-810 nm with a shoulder at 410-420 nm for emeraldine salt (ES) phase of PA, POT and PA-POT without any doping salt. In the presence of salts, a shift for these absorption spectra is observed to lower wavelength in 760-800 nm, however, a shift of shoulder is to higher wavelength in 435-445 nm. In the overall study, an increase in conductivity is observed for all above-mentioned dopants, and among these, K 2 SO 4 is found to be the best in sulphate category and KCl in chloride category.