Search Results (4)

This study achieved the decoration of poly-3-methyl aniline (P3MA) with As₂O₃–As(OH)₃ using K₂S₂O₈ and NaAsO₂ on the 3-methyl aniline monomer. This resulted in a highly porous nanocomposite polymer composite with wide absorption optical behavior, an average crystalline size of 22 nm, and a 1.73 eV bandgap. The photoelectrode exhibited a great electrical response for electroanalytical applications, such as photon sensing and photodiodes, with a J_ph of 0.015 mA/cm² and J_o of 0.004 mA/cm². The variable J_ph values ranged from 0.015 to 0.010 mA/cm² under various monochromatic filters from 340 to 730 nm, which demonstrates high sensitivity to wavelengths. Effective photon numbers were calculated to be 8.0 × 10²¹ and 5.6 × 10²¹ photons/s for these wavelength values, and the photoresponsivity (R) values were 0.16 and 0.10 mA/W, respectively. These high sensitivities make the nanocomposite material a promising candidate for use in photodetectors and photodiodes, with potential for commercial applications in highly technological systems and devices. Additionally, the material opens up possibilities for the development of photodiodes using n- and p-type materials. Full article

Magnetic/conducting polymeric hybrid core-shell typed zinc ferrite (ZnFe₂O₄)/poly(N-methyl aniline) (PMA) particles were fabricated and adopted as electrorheological (ER) and magnetorheological (MR) fluids, and their rheological properties were examined. Solvo-thermally synthesized ZnFe₂O₄ was coated with a conducting PMA through chemical oxidation polymerization. The size, shape, and chemical composition of the final core-shell shaped particles were scrutinized by scanning electron microscopy, transmission electron microscopy, and Fourier transform-infrared spectroscopy. The crystal faces of the particles before and after coating with PMA were analyzed by X-ray diffraction. The ZnFe₂O₄/PMA products were suspended in silicone oil to investigate the rheological response to electro- or magnetic stimuli using a rotating rheometer. The shear stresses were analyzed using the CCJ equation. The dynamic yield stress curve was suitable for the conductivity mechanism with a slope of 1.5. When magnetic fields of various intensities were applied, the flow curve was analyzed using the Hershel–Bulkley equation, and the yield stresses had a slope of 1.5. Optical microscopy further showed that the particles dispersed in insulating medium form chain structures under electric and magnetic fields. Via this core-shell fabrication process, not only spherical conducting particles were obtained but also their dual ER and MR responses were demonstrated for their wide potential applications. Full article

This work reports on a reduced graphene oxide and poly(aniline) composite (rGO-PANI), with rGO clusters inserted between PANI chains. These clusters were formed due the plasticizing effect of N-methyl-2-pyrrolidone (NMP) solvent, which was added during the synthesis. Further, this composite was processed as thin film onto an interdigitated electrode array and used as the sensitive layer for ammonia gas, presenting sensitivity of 250% at 100 ppm, a response time of 97 s, and a lowest detection limit of 5 ppm. The PANI deprotonation process, upon exposure to NH₃, rGO, also contributed by improving the sensitivity due its higher surface area and the presence of carboxylic acids. This allowed for the interaction between the hydrogen of NH₃ (nucleophilic character) and the -COOH groups (electrophilic character) from the rGO surface, thereby introducing a promising sensing composite for amine-based gases. Full article

Three sterically-enhanced 2-imino-6-(1-naphthyl)pyridines, 2-{CMe=N(Ar)}-6-(1-C₁₀H₇)C₅H₃N [Ar = 2,6-i-Pr₂C₆H₃ (L1_dipp), 2,4,6-i-Pr₃C₆H₂ (L1_tripp), 4-Br-2,6-i-Pr₂C₆H₂ (L1_Brdipp)], differing only in the electronic properties of the N-aryl group, have been prepared in high yield by the condensation reaction of 2-{CMe=O}-6-(1-C₁₀H₇)C₅H₃N with the corresponding aniline. Treatment of L1_dipp, L1_tripp and L1_Brdipp with two equivalents of AlMe₃ at elevated temperature affords the distorted tetrahedral 2-(amido-prop-2-yl)-6-(1-naphthyl)pyridine aluminum dimethyl complexes, [2-{CMe₂N(Ar)}-6-(1-C₁₀H₇)C₅H₃N]AlMe₂ [Ar = 2,6-i-Pr₂C₆H₃ (1a), 2,4,6-i-Pr₃C₆H₂ (1b), 4-Br-2,6-i-Pr₂C₆H₂ (1c)], in good yield. The X-ray structures of 1a–1c reveal that complexation has resulted in concomitant C–C bond formation via methyl migration from aluminum to the corresponding imino carbon in L1_aryl; in solution, the restricted rotation of the pendant naphthyl group in 1 confers inequivalent methyl ligand environments. The ring opening polymerization of ε-caprolactone employing 1, in the presence of benzyl alcohol, proceeded efficiently at 30 °C producing polymers of narrow molecular weight distribution with the catalytic activities dependent on the nature of the substituent located at the 4-position of the N-aryl group with the most electron donating i-Pr derivative exhibiting the highest activity (1b > 1a > 1c); at 50 °C 1b mediates 100% conversion of the monomer to polycaprolactone (poly(CL)) in one hour. In addition to 1a, 1b and 1c, the single crystal X-ray structures are reported for L1_dipp and L1_tripp. Full article