Poly(2-methoxyaniline-5-sulfonic Acid) - Surfactant Complexes and Their Redox and Solvatochromic Behaviour

2007 ◽  
Vol 60 (3) ◽  
pp. 159 ◽  
Author(s):  
Simon E. Moulton ◽  
Yingpit Pornputtkul ◽  
Leon A. P. Kane-Maguire ◽  
Gordon G. Wallace
Keyword(s):  
Indium Tin Oxide ◽  
Sulfonic Acid ◽  
Polymer Chains ◽  
Oxidation States ◽  
Emeraldine Base ◽  
Applied Potential ◽  
Emeraldine Salt ◽  
Salt Form ◽  
Base Form ◽  
Redox Switching

Novel stoichiometric (1:1) complexes between the anionic conducting polymer poly(2-methoxyaniline-5-sulfonic acid) (PMAS) and a range of cationic ammonium surfactants have been prepared and characterized. The supramolecular PMAS–surfactant complexes are stable in chloroform and ethanol solutions, in which the PMAS moiety adopts an ‘extended coil’ conformation. Thin films of the complexes can be cast onto indium tin oxide-coated glass from these solutions. The application of an appropriate applied potential leads to redox switching of the PMAS from the emeraldine salt form to its pernigraniline and leucoemeraldine oxidation states. Immersion of the PMAS–surfactant films in 1.0 M NaOH causes the PMAS moiety to undergo conversion into a ‘compact coil’ conformation rather than alkaline de-doping to the emeraldine base form. When the PMAS–surfactant complexes are dissolved in polar organic solvents such as N,N-dimethylformamide, N-methylpyrrolidinone, and acetone, they undergo marked solvatochromism, which is interpreted in terms of rearrangement of the PMAS polymer chains from an ‘extended coil’ to a ‘compact coil’ conformation.

scholarly journals Chemical Oxidative Synthesis and Characteristion of Organica acid Doped Soluble Conducting Poly(o-anisidine)

2009 ◽  
Vol 3 (2) ◽  
pp. 95-99
Author(s):  
Vasant Chabukswar ◽  
◽  
Ganesh Sable ◽  
Keyword(s):  
Acrylic Acid ◽  
Tartaric Acid ◽  
Sharp Peak ◽  
Emeraldine Base ◽  
Spectral Studies ◽  
Ammonia Vapor ◽  
Emeraldine Salt ◽  
Base Form ◽  
Doped Polymer ◽  
Polymerization Method

Synthesis of poly(o-anisidine) with and without acrylic acid doping is carried out by chemical oxidative polymerization method. This is a new polymerization method for the direct synthesis of the emeraldine salt of poly(o-anisidine), i.e. it is directly soluble in known organic solvent such as m-cresol, N-methyl pyrrolidone (NMP), DMSO, DMF, etc. without the need for a conversion of salt phase to base form. The reaction is unique since it eliminates the post processing step which involves neutralization of emeraldine salt to form emeraldine base and again reprotonating the base with a secondary protonic acid. The acrylic acid doped polymer prepared using tartaric acid is comparatively more soluble in m-cresol and NMP than the poly(o-anisidine) prepared without acrylic acid. UV-visible spectra for acrylic acid doped poly(o-anisidine) reveals the coil conformation at higher wavelength ~800–1000 nm along with sharp peak ~440 nm, which may be attributed to secondary doping due to extended coil conformation. Whereas in the presence of NMP as a solvent, the extended tail at higher wavelength disappears while a sharp peak (~630 nm) is observed representing the polymer insulting emeraldine base form. This fact confirms the effect of the solvent on the polymer properties. This is further manifested by the FT-IR spectral studies. Broad and intense band at ~3300–3200cm–1 and 1100–1200 cm–1 in acrylic acid doped polymer accounts for higher degree of doping. The conductivity of acrylic acid doped poly(o-anisidine) is greater than poly(o-anisidine) without acrylic acid. The change in resistance of tartaric acid doped poly(o-anisidine) prepared in acrylic acid media upon its exposure to ammonia vapor suggests the applicability of these polymeric materials for ammonia.

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.

Nonlinear Optical Properties of Polyaniline

1987 ◽  
Vol 109 ◽  
Author(s):  
A. J. Epstein ◽  
J. M. Ginder ◽  
M. G. Roe ◽  
T. L. Gustafson ◽  
M. Angelopoulos ◽  
...  
Keyword(s):  
Optical Properties ◽  
Laser Intensity ◽  
Emeraldine Base ◽  
Photoinduced Absorption ◽  
Salt Form ◽  
Time Resolved ◽  
Base Form ◽  
Exciton Decay ◽  
Base Polymer ◽  
Molecular Excitons

ABSTRACTPolyaniline is a family of polymers whose electronic and optical properties can be controlled through variation of the number of electrons and protons on the polymer chain. For example, the emeraldine base form of the polymer (EB) is insulating while the emeraldine salt form (ES) is metallic. We present here results for photoinduced absorption spectroscopy of the emeraldine base form of polyaniline. Unlike earlier studied polymers, the spectrum of emeraldine base contains both subgap photoinduced bleaching (at 1.8 eV) and photoinduced absorption (at 0.9, 1.4, and 3.0 eV). The existence of the bleaching peak is consistent with a model of optically excited localized molecular excitons in the emeraldine base polymer. The energies of the three photoinduced absorptions peaks and an associated interband bleaching (at energies greater than ∼3.5 eV) are in agreement with the photogeneration of polaron pairs. Laser intensity studies support that the excitons decay monomolecularly while the polarons decay bimolecularly. Picosecond time-resolved spectroscopy of the exciton decay demonstrates the rapid response of this system.

Electrochemical Synthesis of Optically Active Polyanilines

1998 ◽  
Vol 51 (1) ◽  
pp. 23 ◽  
Author(s):  
Mir Reza Majidi ◽  
Leon A. P. Kane-Maguire ◽  
Gordon G. Wallace
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Quartz Crystal ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Spectroscopic Studies ◽  
Optically Active ◽  
Emeraldine Base ◽  
Applied Potential ◽  
Potential Cycling ◽  
Glass Electrodes

The synthesis of optically active polyaniline salt films of the type PAn.HCSA (HCSA = camphor-10-sulfonic acid) has been achieved via the enantioselective electropolymerization of aniline on indium-tin-oxide (ITO)-coated glass electrodes in the presence of (+)- or (–)-HCSA. Similar results were obtained under potentiostatic, galvanostatic and potentiodynamic conditions. The chiroptical and electrical properties of these novel materials have been characterized by u.v.–visible and circular dichroism (c.d.) spectroscopy, electrochemical quartz crystal microbalance techniques and resistometry. The intensity of the c.d. spectra of potentiostatically grown PAn.(+)-HCSA films was found to increase with increasing applied potential over the range 0·8–1·1 V (v. Ag/AgCl) and with increasing charge consumed. C.d. spectroscopic studies also showed that the polyaniline chains retained their initial configuration when the (+)-HCSA dopant acid in PAn.(+)-HCSA films was replaced by HCl via potential cycling in 1 mol dm-3 HCl. Similarly, chemical de-doping of PAn.(+)-HCSA with 0·5 mol dm-3 NH4OH produced optically active emeraldine base, which upon re-doping with HCl gave optically active PAn.HCl with a c.d. spectrum very similar to that of the original PAn.(+)-HCSA. These results suggest that chiral holes may be formed in the polymer matrix during both redox and chemical de-doping/re-doping cycles with PAn.(+)-HCSA salt films.

Coating of Polyaniline with an Insulating Polymer to Improve the Power Efficiency of Electrorheological Fluids

1999 ◽  
Vol 13 (14n16) ◽  
pp. 1931-1939 ◽  
Author(s):  
J. Akhavan ◽  
K. Slack ◽  
V. Wise ◽  
H. Block
Keyword(s):  
Power Efficiency ◽  
Electrorheological Fluids ◽  
Emeraldine Base ◽  
Heavy Duty ◽  
Base Form ◽  
Static Yield ◽  
High Fields ◽  
Er Fluids ◽  
Er Fluid ◽  
A Current

Currents drawn under high fields often present practical limitations to electrorheological (ER) fluids usefulness. For heavy-duty applications where large torques have to be transmitted, the power consumption of a ER fluid can be considerable, and for such uses a current density of ~100μ A cm -2 is often taken as a practical upper limit. This investigation was conducted into designing a fluid which has little extraneous conductance and therefore would demand less current. Selected semi-conducting polymers provide effective substrates for ER fluids. Such polymers are soft insoluble powdery materials with densities similar to dispersing agents used in ER formulations. Polyaniline is a semi-conducting polymer and can be used as an effective ER substrate in its emeraldine base form. In order to provide an effective ER fluid which requires less current polyaniline was coated with an insulating polymer. The conditions for coating was established for lauryl and methyl methacrylate. Results from static yield measurements indicate that ER fluids containing coated polyaniline required less current than uncoated polyaniline i.e. 0.5μ A cm -2. The generic type of coating was also found to be important.

scholarly journals Influence of Thermal Annealing on the Electrical Properties of Poly(3-hexylthiophene)-Based Thin Film Diodes

2007 ◽  
Vol 62 (10-11) ◽  
pp. 609-619 ◽  
Author(s):  
Zivayi Chiguvare ◽  
Jürgen Parisi ◽  
Vladimir Dyakonov
Keyword(s):  
Thin Film ◽  
Thermal Annealing ◽  
Indium Tin Oxide ◽  
Bulk Heterojunction ◽  
Polymer Chains ◽  
Hole Injection ◽  
Before And After ◽  
Output Characteristics ◽  
Al Thin Film ◽  
Poly Styrene Sulfonate

The effects of thermal annealing on the bulk transport properties of poly(3-hexylthiophene) (P3HT) were studied by analyzing room temperature current-voltage characteristics of polymer thin films sandwiched between indium tin oxide/poly[ethylene dioxythiophene]:poly[styrene sulfonate] (ITO/PEDOT:PSS) and aluminum electrodes, before and after a thermal annealing step. It was observed that annealing takes place in two steps: (1) Dedoping of the polymer of impurities such as oxygen, remnant solvent, water, leading to a decrease in the conductivity of the film, and (2) thermally induced motion of the polymer chains leading to closer packing, thus, stronger inter-chain interaction and, consequently, increase in conductivity. It was also observed that the ITO/PEDOT:PSS/P3HT hole injection barrier increases on annealing the ITO/PEDOT:PSS/P3HT/Al thin film devices. The implications of impurity dedoping and closer packing on the output characteristics of bulk heterojunction polymer-fullerene thin film solar cells are discussed.

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.

scholarly journals Synthesis and Characterization of a Novel Class of Lewis Acid Doped Tetraaniline

2012 ◽  
Vol 9 (3) ◽  
pp. 1085-1090 ◽  
Author(s):  
K. Basavaiah ◽  
A. V. Prasada Rao
Keyword(s):  
Boron Trifluoride ◽  
Boron Trifluoride Etherate ◽  
Emeraldine Base ◽  
X Ray Diffraction ◽  
Step Method ◽  
Ammonium Persulphate ◽  
Novel Structure ◽  
Base Form ◽  
Diffraction Patterns

Boron trifluoride (BF3) doped tetraaniline with novel structure were successfully synthesized via two step method. In the first step, emeraldine base form tetraaniline was synthesized via oxidative chemical polymerization of N-phenyl-1, 4-phenylenediamine using ammonium persulphate as oxidant. In the second step involves control BF3doping of tetraaniline using boron trifluoride etherate. As synthesized BF3doped tetraaniline have been well characterized by UV-Visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction patterns (XRD), and scanning electron microscopy (SEM) and thermogravimetry. Thermogravimetry studies revealed that the BF3doping improved the thermal stability of tetraaniline.

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