Polychalcones based on triphenylamine and carbazole building blocks via Claisen–Schmidt route

Alternating and random copolymers of carbazole and triphenylamine containing polychalcones are prepared by adopting simple Claisen–Schmidt route via A₂ + B₂ approach. Terephthaldehyde derivative was used as an additional comonomer along with bisaldehyde of triphenylamine to obtain a random copolymer. The prepared polymers are readily soluble in common organic solvents and the polymers exhibited narrow poly dispersity. The polymers are thermally stable and no observable degradation is observed until 350°C. Further, the spin cast thermally annealed films on glass substrate indicated corrugated surface as measured by scanning electron microscope and atomic force microscopy, which could facilitate for greater interaction at the interfaces. Photophysical properties of the polymers in solution and in thin film showed excellent emission characteristics. Both alternating and random copolymers showed a high quantum yield of 0.74 on comparison with quinine sulfate. Polychalcones with triphenylamine/carbazole showed oxidative response in cyclic voltammetry which suggested the suitability as electrochemical sensors and antioxidant coating material.     

Studies on heterocyclic amines based cardanol-benzoxazine for oil-water separation

The present work describes the development of sustainable bio-benzoxazines for oil water separation and its composites for applications where a low dielectric constant is required. In addition, cardanol benzoxazine monomers (C-ida and C-pyta) with low curing temperature were designed with inbuilt catalytic core using two different heterocyclic amines, namely tetra aryl imidazole diamine (ida) and pyridine core triamine (pyta). Cotton fabric coated with poly(C-ida) and poly(C-pyta) show water contact angle values of 160° and 164°, respectively. The oil-water separation efficiency of the polybenzoxazines coated cotton fabrics was 95%. Further, the poly(C-ida) and poly(C-pyta) matrices were reinforced with varying weight percentages (1, 3, 5, 7, and 10 wt%) of glycidylpropoxytrimethylsilane-functionalized biosilica. The benzoxazine matrices and composites obtained were characterized using different analytical techniques in order to assess their molecular structure, cure behavior, thermal stability, morphology, surface, and dielectric behavior. Data obtained from different studies suggest that these matrices and composites can be used as coatings for oil-water separation and high-performance micro-electronics insulation applications under adverse environmental conditions.     

Nickel hexacyanoferrate film coated pencil graphite electrode as sensor and electrode material for environment and energy applications

In this present work, a simple electroless deposition method is used for the fabrication of hexacyanoferrate(III)-nickel deposited pencil graphite (HCF-Ni-PGE) electrode and applied as an electrochemical sensor for selective and simultaneous determination of ortho- I and para- nitrophenol II isomers. The fabricated HCF-Ni-PGE was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, and elemental mapping. The electrochemical analysis was carried out using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques in 0.1 M KCl containing K₄[Fe(CN)₆]. The redox (Fe^2+/3+) peak currents were enormously increased due to the successful enhancement in the electroactive surface area of PGE from 0.4 to 1.57 cm² for HCF-Ni-PGE. Further, CV and EIS support the HCF and Ni coating on the PGE surface enhanced the electronic conductivity of HCF-Ni-PGE. The electrochemical sensor application of HCF-Ni-PGE was analysed using CV and differential pulse voltammetry towards the determination of o- and p-NP in 0.1 M PBS (pH 6.0). The reduction currents of I and II at HCF-Ni-PGE was enhanced two times compared with the PGE with better resolution. This, the enhanced activity is due to the positive synergetic effect which increased an electroactive surface area, and electronic conductivity. The limit of detection (LOD) values at HCF-Ni-PGE for I and II isomers are 1.98 × 10⁻⁷ and 1.43 × 10⁻⁷ M with S/N = 3, respectively. The practical applicability of the electrochemical sensor has been investigated in the presence of common interfering agents such as Na⁺, SO₄²⁻ and phenol. The simple electroless deposition used for the fabrication of HCF-Ni-PGE electrode possessed high surface area and high conductivity, it can also be applicable in the field of energy storage devices of supercapacitor, and battery, fuel cells and solar cells as electrode materials and photocatalysts.