Ionic liquids like 1-butyl-3-methylimidazolium chloride ([BMIM] Cl, 1-butyl-3-methyl-imidazolium hexafluorophosphate [BMIM] PF6, 1-butyl-3-methyl-imidazolium tetrafluorobrate [BMIM] BF4, 1-butyl-3-methyl-imidazolium bis (trifluoromethylsulfonyl) imide [BMIM] NTf2) were used as doping elements in polyaniline. Pure polyaniline (EB) and polyaniline doped with different anions of ionic liquids (ESs) were chemically synthesized using ammonium peroxydisulphate (APS) and ionic liquids as oxidants. Junctions have been prepared by evaporating chalcogenide materials (ZnSe, CdSe) on conducting polyaniline (EB & ESs) pellets using a vacuum evaporation technique. I-V characteristics of junctions have been studied at room temperature using the Keithley electrometer 6517A. I-V measurements show the rectification effect. A junction of ES [BF4−] anion may be preferred over the other junctions due to its low ideality factor and maximum rectification ratio.

Polyaniline (PANI-EB) containing ZFe2O4 (Z is an element in a divalent state; Z2+ = Fe2+, Co2+, Ni2+, Mn2+, and Zn2+) nanocomposites were successfully synthesized by using 1-butyl-3-methyl-imidazolium bromide [BMIM]Br and cetyl trimethylammonium bromide (CTAB) via in situ polymerization. Structural, morphological, spectroscopic and magnetic properties were investigated by transmission electron microscopy (TEM), X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM) respectively. The presence of polyaniline, [BMIM]Br and CTAB on the surface of the ZFe2O4 nanoparticles was confirmed with FTIR. The purity of the products was proved by XRD. The results of thermogravimetric analysis indicated that the addition of ZFe2O4 nanoparticles to PANI improved the thermal stability of the nanocomposites. The magnetization curves verify that the sample has ferromagnetic behavior at the temperature of 400 K. Magnetic measurements revealed that product has uniaxial anisotropy instead of expected cubic anisotropy according to the Stoner-Wohlfarth model.

No abstract

MnFe2O4 nanoparticles were successfully synthesized via a simple sonochemical reaction by using 1-butyl-3-methylimidazolium bromide ionic liquid and cetyl trimethylammonium bromide as surfactant. MnFe2O4 nanoparticles with ionic liquid were added to polystyrene for preparation of magnetic polymeric nanocomposites. Structural, morphological, spectroscopic, magnetic and dielectric properties were investigated by means of transmission electron microscopy, X-ray powder diffractometry, Fourier transform infrared spectroscopy and vibrating sample magnetometry respectively. The results of thermogravimetric analysis indicated that the addition of MnFe2O4 nanoparticles with ionic liquid to polystyrene improved the thermal stability of the nanocomposite. The magnetization curves elucidate that the MnFe2O4 nanoparticles with ionic liquid/polystyrene nanocomposite has ferromagnetic behavior and improved saturation magnetization, coercivity and remanent magnetization. The electrical quantities such as dielectric constant (ε′), imaginary permittivity (ε″) and dielectric loss (tan (δ) = ε″/ε′) of MnFe2O4 nanoparticles and MnFe2O4 nanoparticles with ionic liquid/polystyrene nanocomposite were evaluated for temperature and frequency dependence. The obtained results are enhanced due to increase in the temperature and decreased with increasing frequency in MnFe2O4 nanoparticles with ionic liquid/polystyrene nanocomposite.

A junction of emeraldine salt (ES [BF4 −]) doped by [BMIM] [BF4] may be preferred over the other junctions due to its low ideality factor and maximum rectification ratio. Schottky barrier diode based on composite of polyaniline (ES [BF4 −]) with polystyrene has been created and characterized using aluminium as Schottky contact and argent as an ohmic contact. The observed current–voltage characteristics can be satisfactorily fitted using the modified Schottky equation. Capacitance–voltage (C–V) in reverse bias and current–voltage (I–V) plots indicates a rectification. Various junction parameters were calculated from the temperature dependent I–V and C–V data and discussed. These results indicate that the composite materials have better mechanical strength and diode quality compared to the pure semiconducting polymer.