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o-toluidine was polymerized with the incorporation of different amount of titanium dioxide (TiO2) by chemical oxidation method using potassium perdisulphate as oxidizing agent. Comparative studies were carried out with different nanocomposites of varying compositions of TiO2/PoT against poly-o-toluidine (PoT). The resulting poly-o-toluidine – TiO2 nanocomposites (PoTTNCs) were characterized by UV–Vis and FTIR spectral studies. TiO2 has a deep influence in the crystallinity of PoT chains order in nanocomposite structure as observed in the XRD pattern. Electrochemical characterization studies were carried out to compare the improved performance of varied compositions of TiO2/PoT with respect to PoT in different atmospheres.

Co3O4 - MnO2 - ZnO NPs were synthesized by making use of the equimolar solutions of cobalt chloride, manganese(II) sulfate and zinc sulfate in aqueous sodium hydroxide and refluxed at elevated temperature. The synthesized mixed nano oxides were characterized by FT-IR, XRD, UV - Vis DRS, TEM, SAED, SEM, EDAX, AFM, TG/DTG and DSC. The FTIR spectra confirm the presence of M-O bonds (M = Co, Mn, Zn). The size of the Co3O4 - MnO2 - ZnO NPs are found to be 10.13 - 25.65nm through XRD studies. The XRD patterns also expose that the particle size is significantly increased with increasing concentration of the precursors. UV-Vis diffuse reflectance spectra (DRS) show that the ternary nanoparticles can be activated by UV and visible light illumination. The TEM, SEM and AFM micrographs of 0.1M Co3O4 - MnO2 - ZnO NPs show roughly spherical shape with size ranging from 10 - 30nm. EDAX analysis confirms the presence of Co, Mn, Zn and O. From TG-DTG and DSC studies, it is found that Co3O4 - MnO2 - ZnO NPs are thermally stable. The photocatalytic activity of Co3O4 - MnO2 - ZnO NPs was determined for degradation of methylene blue (MB) under sunlight. Among the samples, 0.1M Co3O4 - MnO2 - ZnO NPs exhibits the best performance (91.98%) for the degradation of MB in 90 min of irradiation time under sunlight. The factors influencing the photocatalytic activity are pH of dye solution, photocatalyst particle size, photocatalyst dosage and dye concentration.

Reactive Red 195 was detected from industrial waste samples electrochemically on graphene modified glassy carbon electrode (GCE), using both bare and surface changed GCE at different pH media from 1.0 to 13.0. The optimum pH was determined to be 4.0. RR 195 exhibited good linear responds at pH 4.0 on both electrode surfaces. Other parameters, such as accumulation potential, accumulation time, initial scan potential, pulse height, pulse width, and potential scan increment and scan rate are optimized and calibration plot was also derived on different concentrations of the dye. The stripping voltammetric behavior of dye exhibits very low limit of detection on graphene coated electrode (30 ppb). The adsorption of compound on GCE and graphene coated GCE are confirmed using atomic force microscopy studies.

The voltammetric behaviour of 4-nitroso-N,N–dimethylaniline (4-NDMA) was investigated on plain glassy carbon electrode (GCE) and multi-walled carbon nanotube modified GCE (MWCNT/GCE) using cyclic voltammetry. Effects of pH, scan rate and concentration were studied. The surface morphology of the modified electrode in the absence and presence of 4-NDMA molecules was characterized by atomic force microscope (AFM). A systematic study on the variation of experimental parameters with differential pulse stripping voltammetry (DPSV) was carried out and the optimized experimental conditions were arrived. MWCNT/GCE performed well compared with the plain GCE system and the limit of detection (LOD) was found to be 7.5 ng/mL 0.1056 ng/mL for 4-NDMA on plain GCE and MWCNT/GCE respectively.

A new series of metal(II) complexes 1–5 of the type [M(L)(AcO)2H2O], where L is a bidentate ligand, 2-(3-morpholinopropylimino)methylphenol and M is Mn(II) (1), Co(II) (2), Ni(II) (3), Cu(II) (4), and Zn(II) (5), have been isolated and characterized by physico-chemical and spectral methods. Spectroscopic data supported the square pyramidal geometry around the central metal ion in the complexes 1–5. Absorption spectra and viscometric data indicated that the complexes 1–5 interacted with calf thymus (CT) DNA via intercalative strategy. Cleavage activities of complexes 1–5 with CT DNA were analyzed by gelelectrophoretic method. The in vitro antioxidant activity of complexes 1–5 was tested using the DPPH assay. The complexes 1–5 have been tested for antimicrobial activity against some pathogenic bacterial and fungal species by the agar well diffusion method.

A systematic study on the preparation of tin oxide nanoparticles using the precipitation method has been conducted. The preparation of nanomaterials was by varying reaction parameters such as pH and temperature. The tin oxide nanoparticles were characterized by using AFM, SEM, XRD and UV-Vis. Particle size was obtained using XRD studies the value is 28.8 nm, 35.2 nm, 30.8 nm and 33.8 nm. It was found that the alteration of pH and temperature changes the particle size.

Department of Chemistry, Rajalakshmi Institute of Technology, Kuthambakkam-600 124, Tamilnadu, India Department of Chemistry, V.O. Chidambaram College, Thoothukudi-628 008, Tamilnadu, India E-mail: cvedhi@rediffmail.com, cvedhi23@gmail.com Fax: 91-461-2310275 Manuscript received online 01 September 2018, accepted 09 October 2018 Synthesis of benzoin α-oxime and 2,6-pyridine dimethanol through eco-friendly method. These synthesized compounds are characterized by UV-Visible, FTIR and NMR spectral techniques. Anti-corrosion behaviour of benzoin α-oxime and 2,6-pyridine dimethanol both the compounds studied with 2 N sulphuric acid on mild steel. The anti-corrosion behaviour of the synthesized compounds was studied by subjecting to weight loss measurements, polarisation studies and electrochemical impedance spectra (EIS) for the assessment of its performance. The studies were made with 2 N sulphuric acid as the corroding medium, but with the inhibitors concentration in the range of 50–350 ppm. The results revealed that the inhibitor studied perform better in the medium and function by the mechanism of adsorption on the metal surface.

An efficient methodology of polyaniline–TiO2 nancomposite (PAniTNC) was developed through various proportions of ceramic added by chemical polymerization at room temperature. The chemical polymerization reactions were carried out using potassium perdisulphate as an oxidizing agent. The particle size of PAniTNC was found in the range of 8–15 nm as analysed by transmission electron microscopy. The Ti–O characteristic stretching bands at 630 and 558 cm−1, indicating the presence of TiO2 in polyaniline matrix was confirmed by fourier transform infrared spectroscopy. The characterization of the nanocomposite crystalline shape was carried out using X-ray diffraction method. Thermogravimetric and differential scanning calorimetry analyses indicate high thermal stability. SEM analysis showed mixed granular nature of the polymer–ceramic nanocomposites. EDX analysis shows the presence of Ti, C and N in composites. Cyclic voltammetric studies exhibit good adherent behaviour on the electrode surface at pH 1.0. It reveals the presence of oxidation peak at 0.417 V and reduction peak at 0.285 V. It has been observed that PAniTNC-modified GCE has good oxygen reduction ability, and also enhances methanol reduction.

Chemical vapor deposition method for the synthesis of β-HgS (meta cinnabar) nanoparticles is reported with bis(cinnamylpiperazinedithiocarbamato)mercury(II) as the single source precursor. Crystalline structure, size, morphology and composition of the products are characterized by X-ray powder diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. PXRD shows (111), (220), (200), (311), (222), (400), (331), (420) reflections characteristic of β-HgS nanoparticles. SEM micrographs display the spherical nature of the b-HgS nanoparticles. EDX analysis showed the presence of Hg and S.HRTEM images confirm the spherical nature of the nanoparticles with their size in the range of 5–10 nm. The results are in agreement with those estimated from the XRD pattern. XPS signals observed at 162.6, 162.8, 222.3, 99.9, and 104.1 eV are due to S2p (3/2, 1/2), S2s (1/2), and Hg4f (7/2, ...

Surfactant doped polyaniline was synthesized in the aqueous solution of aniline and anionic surfactant of perfluorooctanoic acid (PFO) by chemical synthesis using potassium peroxy disulphate as an oxidant by varying the aniline to surfactant ratio. The solubility of the chemically prepared surfactant doped polyaniline (PANI) was ascertained and it showed good solubility in dimethyl sulfoxide (DMSO), dimethylformamide (DMF), acetone, acetonitrile, ethanol, aceticacid, trichloroethylene, dichloromethane, tetrahydrofuran, ethylacetate, diethylether, toluene, chloroform and sparingly soluble in n-hexane and water. The prepared polymers were characterized by fourier transform infrared spectroscopy (FTIR), UV-visible, X-ray diffraction (XRD), cyclic voltammetric (CV), EIS and scanning electron microscopy (SEM). The analysis of UV-visible and FTIR showed that aniline has been polymerized to PANI in its conducting emeraldine form. FTIR spectra showed that the peaks at 1670, 3315 and 1400 cm-1 corresponded to PFO. FTIR spectra showed that amine peak observed at 1593 cm-1 was shifted to lower wave number due to the interaction between PANI and the surfactant. SEM analysis showed that the variation in morphology of doped PANI was predominantly dependent on the concentration of the surfactant. Elemental analysis was done by energy dispersive spectroscopic (EDAX) which shows the presence of C, N, O, S and F. XRD pattern showed that the formation of nanosized (18 nm) and crystalline polymer. CV studies of the synthesized polymer exhibited good adherent behavior on electrode surface. It exhibited three oxidation peaks at approximately 0.283 V, 0.541 V and 0.989 V and two reduction peaks at 0.1421 and 0.3854 V. Electrical conductivity of PFO doped PANI was studied by impedance spectroscopic method.

Background Calcium channel blockers belonging to the dihydropyridine family have been used as a potent arterial vasodilator in the management of angina and cardiovascular diseases. In the design of glassy carbon electrode coatings for the study of the same, multiwall carbon nanotubes (MWCNT) are favored. They are known for the reduction and oxidation of electroactive species towards cathodic and anodic direction with the simultaneous enhancement of the peak current. Results The MWCNT-modified glassy carbon electrode exhibited a sharp anodic peak potential at around at 0.5 V for amlodipine (AMLD) andnimodipine (NIMD), and 0.4 V for felodipine (FELD) in the cyclic voltammograms. The antihypertensive drugs were determined using a simple two-step procedure developed which comprised a preconcentration step followed by the differential pulse stripping voltammetric quantification. Concentration calibrations were linear within the range from 0.01 to 0.3 μg/mL for AMLD and FELD, and 0.025 to 0.3 μg/mL for NIMD. Conclusion The lower limit detection (LOD) was found to be very low on modified electrode. The LOD is 0.005 μg/mL for AMLD and FELD, and 0.01 μg/mL for NIMD. The prepared electrode showed an excellent electrocatalytic activity towards the oxidation of antihypertensive drugs leading to a remarked improvement in sensitivity. An electrochemical sensor featuring the MWCNT-modified electrode was applied successfully as the result for the calcium channel blocker determination in pharmaceutical samples.

MnO2–ZrO2 nanorods were prepared by wet chemical method by mixing the solutions of MnSO4 and ZrOCl2 varying in the range (0.05–0.45 M) in aqueous NaOH at an elevated temperature. The morphologies of the synthesized products are characterized by scanning electron microscopy and transmission electron microscopy (TEM). X-ray diffraction (XRD) and energy-dispersive spectroscopic measurements were also employed for the characterization of the nanostructures. The synthesized nanoparticles were also characterized by ultraviolet visible spectroscopy, Fourier transform infrared spectroscopy, electrochemical impedance and cyclic voltammetric studies. The morphological studies of the nanoparticles revealed particle distribution with uniform rod-like structure. Energy-dispersive analysis indicated the presence of Mn, Zr and O. The nanostructures of the product were characterized by TEM studies and the mixed rod and granular structure that was found clearly indicated the presence of MnO2–ZrO2 mixed oxide. The size of the synthesized nanorod was found to be 20 nm. From XRD studies the size of the nanorods was found to be in the range 39–56 nm calculated by Debye–Scherrer’s formula. Thermal stability of the nanorods was characterized by thermogravimetric and differential scanning colorimetric analysis. Cyclic voltammetric studies exhibit good adherent behavior on electrode surface and good electroactivity at a pH value of 1.0.