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New chromium doped poly( p-toluidine) (Cr-PPT) was synthesized via chemical oxidative polymerization of p-toluidine with potassium dichromate as an initiator in acidic aqueous medium. The spectrophotometric behavior of Cr-PPT in acetone and chloroform as different solvents was investigated. Cr-PPT exhibits bathochromically red shift at 46-nm value with the increasing of solvent polarity. The intermolecular charge transfer band peak for Cr-PPT shifted from 422 nm in low-polar solvent (chloroform) to high-polar solvent (acetone) to 468 nm. Optical absorption measurements are used to obtain the energy gap of prepared Cr-PPT. Cr-PPT has an optical band gap ( E g = 1.90 to 2.05 eV) that is located in the semiconductor range. Pink color was observed using Cr-PPT solution in acidic media while it changes sharply to yellow in basic medium. Based on intermolecular charge transfer, the Cr-PPT was used as acid-base indicator. Cr-PPT and phenolphthalein (phph) indicator were used for determination of normality of HCl using standard 0.1 N NaOH, the two indicators gave equal end point values. Using Cr-PPT as a new molecular precursor for the production chromium oxide in nanoscale by thermal decomposition route was studied, and the average size of synthesized Cr2O3 was found in the range of 54-61 nm. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy) is a highly conducting polymer with favorable room temperature (RT) thermoelectric (TE) properties. Recently, nanostructure forms of this polymer have been produced with various morphologies by using different surfactants; however, the effect of these morphologies on the TE figure of merit and TE performance has not been well described. In particular, the TE properties of PPy sheets/films composed of nanoparticles (SNPs) have not yet been investigated. In this work, PPy with various morphologies was synthesized using different surfactants. Nanoparticles, nanotubes, continuous sheets and SNPs were produced and characterized by well-known techniques. The structural and TE properties of the as-synthesized nanomaterials were investigated. The obtained results show that SNPs have improved TE properties compared to nanotubes and nanoparticles. The latter two forms have either higher or lower electrical and thermal conductivities than those of SNPs, which suppress their TE performance. The produced SNPs were able to overcome these limitations, as they have high electrical and low thermal conductivities, which result in a high figure of merit and enhanced TE performance. The best SNPs was found to have a power factor, thermal conductivity and figure of merit of 0.17 μV/m⋅K2, 0.132 W/mK2 and 0.4 × 10−3 at room temperature, respectively. These results might be useful for developing future TE materials and devices. [Display omitted] • Polypyrrole with various morphologies were synthesized using different surfactants. • These are nanoparticles, nanotubes, sheets, sheets composed of nanoparticles (SNPs). • The SNPs have improved thermoelectric (TE) performance compared to others. • The other structures have either higher or lower σ and k , which suppress their TE. • The SNPs are able to overcome these limitations and have higher zT and enhanced TE. [ABSTRACT FROM AUTHOR]

In this research, magnetite particles in a nanoscale were coated with three various weight percentages of poly (aniline co- o -anthranilic acid) copolymer. Aniline and o -anthranilic acid monomers were copolymerized in the presence of Fe 3 O 4 nanoparticles via surface initiated polymerization method. Characterization of nanocomposites was carried out by several analysis techniques including; FT-IR, FE-SEM, TEM, XRD, TGA and UV–vis-Near infrared. FT-IR results showed that pended COOH groups of PANAA are physically interacted to magnetite nanoparticles. Magnetite nanoparticles enhanced the thermal strength of the nanocomposites in the range of 300–800 °C. The XRD analysis revealed that the average crystallite size ranges from 7.59 to 11.14 nm depending on PANAA weight percentage. Thin films of uniform spherical shape of PANAA/magnetite nanocomposite were fabricated by thermal evaporation technique. The values of E g(direct) and E g(indirect) decreased with increasing the thickness of PANAA, while the conductivity increased with increasing of PANAA thickness coated magnetite particles. The conductivity value ranged from 3.73 to 26.98 Ω −1 cm −1 at a photon energy 3.65 eV. Using the nanocomposites in photovoltaic applications was highlighted. [ABSTRACT FROM AUTHOR]

Conducting polymers with a one-dimensional (1D) morphology have a notable advantage for applications as thermoelectric (TE) materials. Compared to globular structures, such polymers can improve the electrical conductivity. The use of a proper organic compound to form a self-degraded template at the optimum concentration might be the key step in producing 1D conducting polymers with enhanced TE properties. In this work, polypyrrole (PPy) with a nanotubular morphology was synthesized in the presence of methyl orange (MO) used as a template. The effect of the MO concentration on the structural and TE properties of PPy was investigated in detail. The results obtained showed that the use of smaller amounts of MO led to the formation of a mixture of PPy nanotubes and a small amount of nanoparticles, while larger amounts of MO produced nanotubes/nanostrips. The intermediate MO values produced perfect PPy nanotubes with rectangular cavities. The optimum value of MO for maximum TE performance was determined. At room temperature (RT), the power factor was recorded as 0.75 μW/m⋅k2. This value was increased to 1 μW/m k2 by heating the sample to 383 K. The RT thermal conductivity of the produced PPy nanotubes was found to vary within the range of 0.033–0.25 W/mK depending on the amount of MO and, hence, the particle morphology. These results showed significant improvement in the figure of merit, z T, and, overall, considerable enhancement in the TE performance of PPy nanotubes, which is superior to that reported thus far. [Display omitted] • One-dimensional polypyrrole, PPy has improved σ compared to that of globular structures. • Methyl orange at optimum concentration is found to be the key step for this improvement. • The thermoelectric, TE performance of perfect PPy nanotubes was significantly enhanced. • The optimum concentration of methyl orange for maximum TE performance is determined. • The TE performance of the produced PPy is found to be superior to those reported so far. [ABSTRACT FROM AUTHOR]

A copolymer of hydrochloric acid doped o-anthranilic acid with o-aminophenol (PAAOAP) was prepared in a highly acidic medium based on the oxidative polymerization in the presence of polyethylene glycol (PEG 200) as a soft template by ferric chloride initiator. The resulting doped hydrochloric acid copolymer (PAAOAP) was characterized by several techniques including FTIR, XRD, SEM, TGA, and UV–Vis–NIR spectrophotometer. A PAAOAP thin film was prepared by spin coating technique with a thickness of 200 ± 3 nm. By applying the specific fabrication conditions summarized in the synthesis of polymer solar cell part and post-production annealing at 323 k, the polymer solar cells were established with a power-conversion efficiency of 8.23%. Interesting thermal stability was studied for these devices. To improve the performance of heterojunction diodes, specific thermal annealing was employed. As a result, the conducting polymer crystallinity and nanoscale morphology were significantly enhanced resulting in improving the collection of charges at the electrode. By this way, the device efficiency was increased by reducing the series resistance of the polymer solar cells. • Copolymer PAAOAP was synthesized by using FeCl 3 in acidic medium. • The resulting PAAOAP was characterized by several techniques. • A PAAOAP thin film was prepared by spin coating technique with a thickness of 200 nm. • Optical properties of the thin film were investigated. • Polymer solar cell (Au/PAAOAP/P-Si/Al) was established with a PCE of 8.23%. [ABSTRACT FROM AUTHOR]