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Copper (Cu)-dipicolonic acid (DPA) based metal-organic coordination polymers (MOCPs) has been evaluated as an electrode material for supercapacitors. Cu-MOCP exhibits specific capacitance of 217.3 F g−1 at 0.4 mA cm−2 and superior capacitance retention of 95.5% after 2000 cycles at 6.7 mA cm−2 in 1.0 M NaOH electrolyte using galvanostatic study. It may arouse from the micro structure in Cu-MOCP that gives enough void for storage and diffusion of electrolyte, suggesting its promising electrode material for supercapacitors.

The newer route of poly (ethylene glycol) (PEG) stabilized the cesium lead iodide (PEG-CsPbI3) light-absorber have prepared for Inorganic perovskite solar cell application. The prepared PEG-CsPbI3, uniform multicrystalline growth on the electrode surface and surface morphologies were observed by the high resolution-tunneling electron microscopy and scanning electron microscopy. PEG-CsPbI3 is in black color cubic crystalline phase at 350 °C that results confirmed by X-ray diffraction pattern. Also, the cubic nature is confirmed through that selected area electron diffraction pattern. From the Fourier transform-infrared spectra, the functional groups of cesium, lead hydroxide and Pb-I-Pb stretching vibrations and the relevant frequency modes is confirmed. The current-voltage curves at 10 mV/S scan rate are performed in the two different directions. The PEG-CsPbI3 coated photo-anode stability is monitored through forward and reverse scan direction maximum 25 days, 3.01% of the average efficiency is achieved by in the 20th days stabilized device, particularly in the reverse scan.

Synthesis of natural products has speeded up drug discovery process by minimizing the time for their purification from natural source. Several diseases like Alzheimer's disease (AD) demand exploring multi targeted drug candidates, and for the first time we report the multi AD target inhibitory potential of synthesized dihydroactinidiolide (DA). Though the activity of DA in several solvent extracts have been proved to possess free radical scavenging, anti bacterial and anti cancer activities, its neuroprotective efficacy has not been evidenced yet. Hence DA was successfully synthesized from β-ionone using facile two-step oxidation method. It showed potent acetylcholinesterase (AChE) inhibition with half maximal inhibitory concentration (IC50) 34.03 nM, which was further supported by molecular docking results showing strong H bonding with some of the active site residues such as GLY117, GLY119 and SER200 of AChE. Further it displayed DPPH and (.NO) scavenging activity with IC50 value 50 nM and metal chelating activity with IC50 >270 nM. Besides, it significantly prevented amyloid β25-35 self-aggregation and promoted its disaggregation at 270 nM. It did not show cytotoxic effect towards Neuro2a (N2a) cells up to 24 h at 50 and 270 nM while it significantly increased viability of amyloid β25-35 treated N2a cells through ROS generation at both the concentrations. Cytotoxicity profile of DA against human PBMC was quite impressive. Hemolysis studies also revealed very low hemolysis i.e. minimum 2.35 to maximum 5.61%. It also had suitable ADME properties which proved its druglikeness. The current findings demand for further in vitro and in vivo studies to develop DA as a multi target lead against AD.

Poly (aryl hexafluoro sulfone benzimidazole) and poly (aryl hexafluoro ethoxy benzimidazole), termed as PArF6SO2BI and PArF6OBI, are synthesized and characterized systematically. PArF6SO2BI membranes illustrate good chemical stability in terms of oxidative weight loss due to the electron-withdrawing sulfone functional group. PArF6OPBI membranes exhibit weak chemical stability after immersion in Fenton's solution. Many of the membranes show good conductivities. Higher conductivities of 3.26 × 10−2 S cm−1 at 160 °C with 286.8 wt% acid doped level for 3:1 (2.335 mmol of 4,4′-sulfonyldibenzoic acid and 7.005 mmol of 2, 2-bis(4-carboxyphenyl) hexafluoropropane) ratio of PArF6SO2BI and 7.31 × 10−2 S cm−1 with 356.9 wt% for 3:1 ratio of PArF6OBI are observed. PArF6SO2BI and PArF6OPBI membranes exhibit good conductivity, thermal and mechanical stabilities which are crucial requirements for high temperature fuel cells.

Novel electrospun nanofiber poly(aryl sulfone ether benzimidazole) (SO2-OPBI) membrane is synthesized for enhanced the proton conductivity and chemical stability. Incorporation of the flexible aryl sulfone- and ether-linkages in the polymer backbone are improved the physico-chemical properties of membranes. We prepared different types of membranes, namely dense SO2-OPBI membrane, nanofiber SO2-OPBI and m-PBI membrane and evaluated their physico-chemical properties for suitability application of high temperature PEM fuel cells. Interestingly, the nanofiber membranes possessed a greatly increased proton conductivity (0.0667 S cm−1 at 160 °C and acid doped level of 338%), which is comparable to that of the dense membrane (0.033 S cm−1 at 160 °C and 221% acid doping). The nanofiber and dense membrane shows good oxidative stability under Fenton reagent.

We report the incorporation of nanoCTO (nanoCaTiO3), prepared by sol-gel methods into the synthetic m-PBI to develop nanoCTO-PBI composite membranes. The macromolecular structure of the membrane shows high conductivity and good oxidative stability. The acid doping level in the membrane was estimated by the amount of phosphoric acid (PA) per specific volume. Increase in the content of nanoCTO results in the increase in conductivity as well as the oxidative stability of the membrane. Higher conductivity observed for 15% nanoCTO-PBI composite membrane as 32.7 mS cm−1, whereas that of 5% nanoCTO-PBI is only 20.2 mS cm−1. The power density and current density of 10% nanoCTO-PBI composite membrane at 0.6 V and 160 °C obtained are 251.4 mW cm−2 and 419 mA cm−2 respectively. Thus, the composite membranes are found to be potential electrolytes for HT-PEM fuel cells with enhanced proton conductivity.

A rapid and simple chemical synthesis of poly(2-aminothiophenol)‑silver (P2ATP-Ag) nanocomposite using conductive and electroactive silver nanoparticles (AgNPs) is reported. The AgNPs was synthesized by chemical reduction method using tri‑sodium citrate as reducing agent and poly(N-vinyl-2-pyrrolidone) (PVP) as stabilizing agent. P2ATP-Ag nanocomposite was synthesized by using potassium peroxodisulphate as oxidant and the samples were characterized. The presence of AgNPs in the composite was confirmed from UV-Vis, FTIR and X-ray diffraction studies. Morphology of the P2ATP and its composite were investigated by SEM. HR-TEM images show spherical, trigonal and rod like morphologies with sizes of Ag nanoparticles and its composite. Thermal analysis revealed that the thermal stability of the P2ATP-Ag nanocomposite is improved when compared with pure P2ATP. The synthesized AgNPs, pure P2ATP and P2ATP-Ag nanocomposite were screened for antibacterial activity test against human pathogen such as Gram positive (Bacillus subtilis, ATCC-6051) and Gram negative (Vibrio cholerae, ATCC-14035), carried out by agar-well diffusion method at micro molar concentration. The result shows that P2ATP-Ag nanocomposite has excellent antibacterial activity due to the presence of Ag nanoparticles. The electrical conductivity of the P2ATP-Ag nanocomposite is better than that of pure P2ATP. The reported nanocomposite will be a potential material for electrocatalysis, sensors and biomedical applications.

A novel fluorescent chemosensor based on a rhodamine derivative (RBD4) was designed, synthesized, and used as a selective Cd2+ ion sensor. The structure of the fluorescence sensor (RBD4) is confirmed through single crystal X-ray study. On the basis of the Forster resonance energy transfer mechanism between rhodamine and pyridine conjugated dyad, a new colorimetric as well as fluorescence probe was synthesized for the selective detection of Cd2+. This sensor shows high selectivity towards Cd2+ ions in the presence of other competing metal ions. On the basis of thorough experimental and theoretical findings, the additions of Cd2+ ions to the solution of RBD4 helps to generate a new fluorescence peak at 590 nm due to the selective binding of Cd2+ ions with RBD4 in a 1: 1 ratio with a binding constant (K) of 4.2524 × 104 M−1. The detection limit of RBD4 for Cd2+ was 1.025 × 10−8 M, which presented a pronounced sensitivity towards Cd2+. The in situ generated RBD4–Cd2+ complex is able to selectively sense S2− over other anions based on the displacement approach, given a remarkable recovery of fluorescence and UV–vis absorption spectra. The fluorescence sensor has also exhibited very good results in HeLa Cells imaging under physiological pH.

Human kinesin Eg5 is a potential inhibiting site for cancer chemotherapy. Blocking metaphase by binding foreign inhibitors with Eg5 eventually leads to apoptotic cell death. Here, we report the pyrazolopyrimidine derivates as potent inhibitors of Eg5 that prevents mitotic kinesin progression. IC50 values were evaluated against the motor domain of Eg5 using steady-state ATPase assay. To better understanding, we have performed molecular docking simulation. It reveals that the interactions of the proposed inhibitors with both the allosteric sites (helices α2, α3 and loopL5, and helices α4 & α6). Out of fifteen pyrazolopyrimidine derivates, three compounds (12, 25, and 27) have shown significant inhibition of Eg5. The synthesized compounds (12, 25, and 27) were tested for their in-vitro anticancer activity against cervical cancer cell line (HeLa).

An electrochemical method for the determination of trace levels of mercury(II) ions using hydroxyapatite (HA) nanoparticles modified glassy carbon electrode (GCE) by square wave voltammetry is described for the first time. HA nanoparticles biosynthesized using Aloe vera plant (Av) extract exhibited improved electrocatalytic activity towards Hg2+ ions when compared to pristine HA. The Av-HA modified GCE showed an excellent selectivity and improved sensitivity towards the detection of Hg2+ without requiring preconcentration of mercury during voltammetric detection. Operational parameters such as pH, supporting electrolyte and scanning potential range were optimized. Under the optimum experimental conditions, the anodic peak current is proportional to the concentrations of mercury over a wide range of 2.0 × 10−7 to 2.1 × 10−4 M with the lowest detectable concentration of 141 nM. The Av-HA modified GCE showed good selectivity towards mercury in the presence of potential interferents such as copper, lead, cadmium, silver and zinc. The fabricated sensor displayed good reproducibility and is suitable for the determination of mercury in tap water and industry waste water.

Kinesin Spindle Protein (KSP) or Eg5 is an essential kinesin that is involved in spindle separation process during mitosis and also unregulated in certain cancer cells. Inhibitors of this enzyme have proved to be effective to block spindle separation followed by mitotic arrest and apoptosis of the cancer cells. Since this enzyme has two allosteric inhibitor binding sites, it's an excellent target for developing drugs for cancer chemotherapy. Many pyrimidine derivatives have been proved to be active against cancer and other enzymes. In this report, we have synthesized a set ten novel N-(1-(6-acetamido-5-phenylpyrimidin-4-yl)piperidin-3-yl)amide derivatives and have evaluated their activity against the KSP. The SAR of these active compounds was further analyzed using in silico molecular docking studies using GOLD and AutoDock softwares. All these compounds form hydrophobic interaction, aromatic π-π stacking and hydrogen bond efficiently with the Eg5.

Simultaneous electropolymerization of 3-methylthiophene and incorporation of Laccase (LAC) was carried out in the presence of propylene carbonate as a medium by amperometric method. This enzyme modified electrode was used for the sensing of polyphenol. Catechol is taken as a model compound for the study. UV-Vis spectral studies suggest no denaturation of LAC in presence of propylene carbonate. The SEM studies reveal the surface morphology and incorporation of LAC in P3MT with agglomerated flaky masses are observed in with and without enzyme micrographs. The cyclic voltammograms were recorded for 0.01 mM catechol on plain glassy carbon, polymer and enzyme incorporated electrodes at pH 6.0 and scan rate 50 mV s−1. The fabricated electrochemical biosensor was used for the determination of catechol in aqueous solution by Differential Pulse Voltammetry (DPV) technique. The concentration linear range of 8×10−8 to 1.4×10−5 M a value of MichealisMenten constant Km=7.67 µmol dm−3 and activation energy is 32.75 kJ mol−1. It retains 83 % of the original activity after 60 days which is much higher than that of other biosensors. The developed biosensor was used to quantify catechol in the determination in real samples.

Electrospun fibrous membranes of hybrid composites of polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN) and silicon dioxide (SiO 2 ) (PVdF–PAN–SiO 2 ) are prepared with different proportions of SiO 2 (3, 5 and 7% w/w). The field emission scanning electron microscopy (FE-SEM) reveals that these membranes have three-dimensional, fully interconnected network structures, which are combined with micropores of fine SiO 2 distribution. The surface roughness of the membranes increases with increasing the SiO 2 content. It is found that 7 wt% SiO 2 /PVdF–PAN electrolyte membrane has the highest ionic conductivity (6.96 × 10 −2 S cm −1 ) due to the large liquid electrolyte uptake (about 570%). As the concentration of SiO 2 nanoparticles increase, the contact angle value also increases, ranging from 135.70° to 140.60° which indicates that the membrane has higher hydrophobicity. The dye sensitized solar cells (DSSCs) are fabricated using the hybrid composite membrane with PVdF–PAN with 7 wt % SiO 2 . Its photovoltaic performance exhibits an open circuit voltage ( V oc ) of 0.79 V and a short circuit current 11.6 mA cm −2 at an incident light intensity of 100 mW cm −2 , producing an efficiency of 5.61%. DSSC, using the hybrid composite electrospun membrane which shows more stable photovoltaic performance than other assembled DSSCs.

The course of the reaction between copper sulfate (CuSO4) and 4-aminodiphenylamine (4ADPA) was monitored by UV-visible spectroscopy in p-toluene sulfonic acid (p-TSA). Formation of poly(4-aminodiphenylamine)/copper nanoparticle composite (P4ADPA/CuNC) was witnessed through the steady increase in absorbance at 410, 580 and >700 nm. The absorbance at 410 nm as well as >700 nm are correlated to the amount of P4ADPA/CuNC formation and was subsequently used to determine the rate of formation of P4ADPA/CuNC (RP4ADPA/CuNC) at any time during the course of the reaction. RP4ADPA/CuNC shows a first-order dependence on [4ADPA] and a half-order dependence on [CuSO4]. A kinetic rate expression was established between RP4ADPA/CuNC and experimental parameters such as [4ADPA] and [CuSO4]. The rate constant for the formation of P4ADPA/CuNC was 8.98 × 10(-3) mol(-0.5) l(0.5) s(-1). Field emission scanning electron and transmission electron micrographs revealed that the morphology of the P4ADPA/CuNC was influenced by the reaction conditions.

Nano size Polypyrrole (PPY) was synthesized electrochemically in presence of three different surfactants namely CTAB, CSA and TTX-100. Cyclic voltammetric studies showed an irreversible oxidation of pyrrole in the presence of surfactants. The currents of the broad peak were 4.26mA, 5.3mA and 8.6mA for PPY/CTAB, PPY/CSA and PPY/TTY-100 respectively. The FT IR spectra of electrochemically synthesized PPY in presence and absence of surfactants were analyzed and the prominent peaks were assigned properly. The presence of N-H group in both cases suggests the presence of pyrrole units in the polymer. From the XRD results the particle sizes of all the four PPYs were determined and the values are as follows: PPY (34 nm), PPY/CSA (31 nm), PPY/CTAB (30nm), PPY/TTX-100 (29 nm). The PPY/TTX-100 exhibited highest electrical conductivity (2.04 ×10−3 S/cm) among other PPY synthesized (PPY/CTAB - 1.13 ×10−3 S/cm, PPY/CSA - 1.09×10−3 S/cm and PPY - 1.27 ×10−3 S/cm). SEM images of PPY/CSA showed agglomerated small polymeric fragments whereas PPY/CTAB showed large sized polymeric plates. Interestingly PPY/TTX–100 showed uniform hollow structure. The presence of surfactants has resulted in uniform polymer formation.

Electroactive copolymer of o-anisidine and ethyl 4-aminobenzoate were synthesized in 1 M HClO4 using cyclic voltammetry on glassy carbon electrode. The copolymer was characterized by FT-IR spectral data. The surface morphology was studied using SEM analysis. The grain size of the copolymer was measured using XRD studies and was found to be 70 nm. The electrical conductivity of the copolymer was 3.14 ×10−3 S cm−1, as determined using a four-probe conductivity meter.

The voltammetric behaviour of two anthraquinone dyes such as Alizarin Red S (ARS) and Reactive blue 4 (RB4) was investigated at plain glassy carbon electrode (GCE), multiwalled carbon nano tube modified GCE (MWCNT/GCE) and zeolite modified GCE (ZE/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 dye molecules was characterized by scanning electron microscopy (SEM). 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 among the three electrode systems and the limit of detection (LOD) was 0.036 µg mL−1 for ARS and 0.05 µg mL−1 for RB4 on this modified system. Suitability of the differential pulse stripping voltammetric method for the trace determination of textile dyes in effluents was also realized.

Superhydrophobic poly(vinylidene fluoride) PVDF-SiO2 composite membranes with different % of SiO2 contents were prepared by electrospinning. The surface morphologies of the membranes are characterized by using scanning electron microscopy. The nanofibers in the membranes were stacked in layers to produce fully interconnected pores that resulted in high porosity. The incorporation of SiO2 into the nanofiber membrane improved the ionic conductivity from 0.2428 × 10-4Scm-1 to 7.731 × 10-4Scm-1 at room temperature. The surface roughness of the membranes increased with increasing the SiO2 content, while the average diameter of nanofibers was rarely affected. Superhydrophobic PVDF membrane with a contact angle larger than 136° was prepared by the electrospinning of the SiO2 functionalized PVDF. The surface composition of the membranes is analyzed by using FTIR and the contact angles and water drops on the surface of the membrane are measured. The contact angle experimental results of PVDF-SiO2 composite membranes showed an improvement of hydrophobicity with % of nano SiO2.

A new electroactive and electrochromic copolymer of 4-aminodiphenylamine (ADPA) and 4,4′-diaminodiphenyl sulfone (DADPS) was synthesized electrochemically in 0.5 M H 2 SO 4 in water and ethanol medium. The electrochemical synthesis of the copolymer by deposition on a glassy carbon electrode (GCE) and its characterization were carried out using cyclic voltammetry (CV). The voltammograms exhibited different patterns of behavior with different feed concentrations of DADPS. Equimolar concentrations of ADPA and DADPS or the combination with slight excess concentration of DADPS demonstrated very efficient growth of the copolymer film on the surface of the GCE. The copolymer is highly soluble in dimethyl sulfoxide (DMSO). The scan rate of this copolymer on GCE showed linear variation, revealing the film's excellent electroactive adherent properties. The effect of pH on the copolymer film showed that the polymer was electrochemically active up to pH 7.0. Spectroelectrochemical analysis of the copolymer film, carried out on an indium tin oxide (ITO) plate, showed multi-color electrochromic behavior when the applied potential was changed. The copolymer was characterized by FTIR and 1 H NMR spectral data. The surface morphology was studied using SEM analysis and the grain size of the copolymer was measured using XRD studies and found to be 28 nm. The electrical conductivity of the copolymer was 3.48 × 10 −2 S cm −1 , as determined using a four-probe conductivity meter.

The electrochemical and electrocatalytic behavior of glassy carbon electrodes modified by one mono and four dihydroxy derivatives of anthra-9,10-quinone compounds have been investigated by cyclic voltammetric technique. The stability of the modified electrodes was ascertained in acidic and neutral media. The surface morphology of modified electrode was characterized by scanning electron microscope. The influence of pH on the electrochemical and electrocatalytic behavior was studied and pH 6.0 or 7.0 was chosen as the optimum working pH by comparing the shift in oxygen reduction potential. The anthraquinone-adsorbed glassy carbon electrodes possess excellent electrocatalytic ability for oxygen reduction with overpotential ranging from 388 to 547 mV lower than that at a plain glassy carbon electrode. Hydrodynamic volatammetric studies were performed to determine the heterogeneous rate constants for the reduction of O2 at the surface of the modified electrodes, mass specific activity of the anthraquinones used, and the apparent diffusion coefficient of O2 in buffered aqueous O2-saturated solutions.

The commendable product selectivity exhibited by the solvents during the reaction of 2-[(2-oxo-2-arylethyl)sulfanyl]-1-aryl-1-ethanones with phenylhydrazine hydrochloride yielding exclusively 1-aryl-2-[(2-aryl-1H-3-indolyl)sulfanyl]-1-ethanones in THF and di(2-aryl-1H-3-indolyl) sulfides in ethanol is described.

Electrochemical copolymerization of o-anisidine with ethyl 4-aminobenzoate was carried out in aqueous 0.1 M HClO4 by employing cyclic voltammetry. Copolymer films were grown for different molar concentration ratios of ethyl 4-aminobenzoate. Electrochemical homopolymerizations of o-anisidine and ethyl 4-aminobenzoate were carried out independently under similar conditions. The copolymers exhibited high solubility in many polar solvents. The scan rate exerted good influence on the polymer effect on this glassy carbon electrode copolymer film, revealing electroactive film's excellent adherent properties. Spectroelectrochemical studies of the copolymer film were carried out on indium tin oxide plates. The copolymer was characterized by FTIR spectral data. The surface morphology was studied using SEM and TEM analysis. The electrical conductivity of copolymer was measured by four-probe conductivity meter.

Poly(4-aminodiphenylamine)-silver nanocomposites were synthesized by an easy one-step aqueous chemical oxidative polymerization of 4-aminodiphenylamine (4ADPA) using silver nitrate (AgNO3) as the oxidant. Two different structure directing surfactants, p-toluene sulfonic acid (p-TSA) and cetyl trimethyl ammonium bromide/hydrochloric acid (CTAB/HCl), were independently used for the nanocomposite (NC) preparation. The NCs prepared in p-TSA and CTAB/HCl medium were designated as P4ADPA/AgNC(p−TSA) and P4ADPA/AgNC(CTAB/HCl), respectively. We investigated the morphological variations in the NCs based on the medium. P4ADPA/AgNC(p−TSA) and P4ADPA/AgNC(CTAB/HCl) were characterized by field emission scanning electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis and UV-visible spectroscopy. Copyright © 2011 Society of Chemical Industry

A facile and sustainable mechanochemical route for the synthesis of undoped polydiphenylamine (PDPA) and inorganic acid doped nanostructures are reported. Field emission scanning electron microscopic (FESEM) images highlighted the formation of distinctly different nanostructures for each of the inorganic acid doped PDPA. Elemental analysis carried out for the polymers revealed the presence of more repeating units in their backbone. The X-ray diffraction (XRD) results of the as-prepared PDPA nanostructures indicated the high degree of crystallinity ever reported for PDPA. Spectroscopic profile of the polymers showed that the prepared PDPA is in a doped conducting form. Electrochemical studies performed for the polymeric particles ascertained the redox behaviour and the good electrochemical activity of obtained PDPA samples. The probable mechanistic aspect behind the formation of PDPA nanostructures through this simple and efficient route is discussed.

Three analgesics, acetaminophen, acetylsalicylic acid, and dipyrone were determined by stripping voltammetry using nanosized poly(3,4-ethylenedioxythiophene)-modified glassy carbon electrode . The cyclic voltammetric behavior of the three analgesics was studied in aqueous acid, neutral, and alkaline conditions. One well-defined oxidation peak each for acetaminophen and acetylsalicylic acid and three oxidation peaks for dipyrone were observed in the cyclic voltammograms. The influence of pH, scan rate, and concentration revealed irreversible diffusion controlled reaction. A systematic study of the experimental parameters that affect the differential pulse stripping voltammetric response was carried out. Calibration was made under maximum peak current conditions. The scanning electron microscope analysis confirmed good accumulation of the drugs on the electrode surface. The range of study for both acetaminophen, acetylsalicylic acid were 0.015–0.4 and dipyrone was 0.025–0.4 μg/ml. The lower limit of determination for both acetaminophen, acetylsalicylic acid was 0.01 μg/mL and for dipyrone was 0.02 μg/mL. The suitability of the method for the determination of the three analgesics in pharmaceutical preparations and urine samples was also ascertained.

Kinetics of chemical oxidative polymerization of 4-aminodiphenylamine (4ADPA) was followed in aqueous 1 M p-toluene sulfonic acid (p-TSA) using silver nitrate (AgNO3) as an oxidant by UV–vis spectroscopy. The medium was found to be clear and homogeneous during the course of polymerization. The absorbances corresponding to the intermediate and the polymer were followed for different concentrations of 4ADPA and AgNO3 and at different reaction time. The appearance of a band around 450 nm during the initial stages of polymerization corresponds to the plasmon resonance formed by the reduction of Ag+ ions. Rate of poly(4-aminodiphenylamine)/Ag nanocomposite (RP4ADPA/AgNC) was determined for various reaction conditions. RP4ADP/AgNC showed second order power dependence on 4ADPA and first order dependence on AgNO3. The observed order dependences of 4ADPA and AgNO3 on the formation of P4ADPA/AgNC were used to deduce a rate equation for the reaction. Rate constant for the reaction was determined through different approaches. The good agreement between the rate constants obtained through different approaches justifies the selection of rate equation.

A solvent-free mechanochemical route for the preparation of poly(2,5-dimethoxyaniline) hydrochloride nanostructures is developed and reported in the article. High conductivity, good crystallinity, and nanostructured morphology are observed for the prepared polymer. This polymeric powder is utilized as a cathode material in hybrid supercapacitor and its electrochemical performance is evaluated and discussed in this short report. The maximum specific capacitance of the poly(2,5-dimethoxyaniline) hydrochloride/activated carbon hybrid supercapacitor is found to be 125 F g−1 at 1 mA cm−2 current density. The cell delivers a specific energy as high as 50 Wh kg−1 at a specific power of 97 W kg−1 and also exhibits an excellent cycle performance with more than 99% coulombic efficiency and the maintenance of 85% of its initial capacitance after 1,000 cycles.

Electroactive conducting copolymers of aniline (ANI) and ethyl 4-aminobenzoate (EAB) were prepared electrochemically. Cyclic voltammetric studies were carried out with different feed concentration of EAB on glassy carbon electrode surface. The voltammograms exhibited different behavior for different concentrations of EAB. The copolymers exhibited high solubility in many polar solvents. The scan rate exerted good influence on the polymer effect on this GCE copolymer film, revealing electroactive film’s excellent adherent properties. The effect of pH on the copolymer film showed that the polymer was electrochemically active up to pH 7.0. Spectroelectrochemical analysis of the copolymer film, carried out on an indium tin oxide (ITO) plate, showed multicolor electrochromic behavior when the applied potential was changed. The color of the copolymer was changed from neutral yellow (422 nm) to green (760 nm) and to blue (600 nm) at the concentration of 0.1 M aniline and 0.1 M EAB in 0.1 M H 2 SO 4 medium. The copolymer was characterized by FT-IR spectral data. The surface morphology were studied using SEM and TEM analysis. The grain size of the copolymer was measured using XRD studies and was found to be 80 nm. The electrical conductivity of the copolymer was 3.21 × 10 −2 S cm −1 , as determined using a four-probe conductivity meter.

The electrocatalytic reduction of dioxygen by one mono and four dihydroxy derivatives of 9,10-anthraquinone (AQ) incorporated in polypyrrole (PPy) matrix on glassy carbon electrode has been investigated. The electrochemical behaviour of the modified electrodes was examined in various pH media and both the formal potential of anthraquinones and reduction potential of dioxygen exhibited pH dependence. AQ and PPy composite film showed excellent electrocatalytic performance for the reduction of O2 to H2O2. pH 6.0 was chosen as the most suitable medium to study the electrocatalysis by comparing the peak potential of oxygen reduction and enhancement in peak current for oxygen reduction. The diffusion coefficient values of AQ at the modified electrodes and the number of electrons involved in AQ reduction were evaluated by chronoamperometric and chronocoulometric techniques, respectively. In addition, hydrodynamic voltammetric studies showed the involvement of two electrons in O2 reduction. The mass specific activity of AQ used, the diffusion coefficient of oxygen and the heterogeneous rate constants for the oxygen reduction at the surface of modified electrodes were also determined by rotating disk voltammetry.

A simple mechanochemical route for the synthesis of high quality inorganic anion doped polydiphenylamines (PDPAs) is reported in this article. Elemental analysis performed for the PDPAs indicated the presence of dopant anions in the polymeric chain. PDPA prepared in the presence of 96 wt% H 2 SO 4 (PDPA–H 2 SO 4 ) was found to be better doped than the other polymeric salts. Spectroscopic profiles of the polymers showed that the PDPAs were in a doped conducting state. The X-ray diffraction (XRD) pattern of the as-prepared polymeric powders revealed the presence of more crystalline phases in PDPA–H 2 SO 4 . Field emission scanning electron microscopic (FESEM) images highlighted the formation of inorganic anion doped PDPA particles with different sizes (80–100 nm). Electrochemical studies performed for the polymeric particles depicted the redox behavior and good electrochemical activity of PDPA salts. Thermogravimetric analysis (TGA)/differential thermal analysis (DTA) proved that all the PDPA salts were thermally stable up to 300 °C. The electrochemical performance of PDPA–H 2 SO 4 in hybrid supercapacitors was evaluated due to its superior physicochemical properties. The maximum specific capacitance of the hybrid supercapacitor constructed out of PDPA–H 2 SO 4 powder was found to be 108 F g −1 .

The crystal structures of 4-(4-methylphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIa) and 4-(4-methoxyphenyl)-6-phenyl-2,3,3a,4-tetrahydro-1H-pyrido[3,2,1-jk]carbazole (IIb) were elucidated by single crystal X-ray diffraction. Compound (IIa), C28H25N, crystallizes in the triclinic system, space group P-1, with a=8.936(2) Å,b=10.490(1) Å,c=11.801(1) Å,α=102.69(5)°, β=103.27(3)°,γ=93.80(1)°, and Z=2. The compound (IIb), C28H25NO, crystallizes in the monoclinic system, space group P21/a, with a=11.376(5) Å,b=14.139(3) Å,c=13.237(4) Å,β=97.41(3)°, and Z=4. In both the structures, the pyrido ring adopts a twist boat conformation and the carbazole molecule has the twisted envelope structure with C3 and C13 at the flap. No classical hydrogen bonds are observed in the crystal structures. Details of the preparation, structures, and spectroscopic properties of the new compounds are discussed.

Pheniramine maleate (PA), an antihistamine, was determined by Differential Pulse Stripping voltammetry using nano polypyrrole (Ppy) and nano poly(3,4-ethylenedioxythiophene) (PEDOT) modified glassy carbon electrodes. The cyclic voltammetric behavior of pheniramine was studied in aqueous acidic, neutral and alkaline conditions. One well-defined oxidation peak was observed in the cyclic voltammograms at all pHs. The influence of pH, scan rate and concentration revealed irreversible electron transfer and the oxidation was diffusion controlled adsorption. The SEM analysis confirmed good accumulation of PA on the electrode surface. A systematic study of influence of various experimental parameters that affect the stripping voltammetric response was carried out and the maximum peak current conditions were arrived at. Calibration was made under maximum peak current conditions. The range of study was 0.05 to 0.4 μg/mL on Ppy/GCE and 0.025 to 0.4μg/mL on PEDOT/GCE and the lower limit of determination were 0.035μg/mL on Ppy/GCE and 0.016μg/mL on PEDOT/GCE. The suitability of the method for the determination of PA in pharmaceutical preparations and urine samples was also ascertained.

A modified electrode fabricated by coating multiwalled carbon nanotubes (MWCNTs)/poly(3-methyl thiophene, P3MT) film on a glassy carbon electrode (GCE) and was used for the adsorptive stripping voltammetric determination of different classes of pesticides. These include herbicide (isoproturon), insecticides (voltage, cypermethrin, deltamethrin, fenvalerate) and an acaricide (dicofol). Electrochemical behaviour of all the selected pesticides was investigated on P3MT/MWCNT/GCE nano composite surface at selected pHs 1, 4, 7, 9.2 and 13. In cyclic voltammetry, isoproturon (ISO) and voltage (VOL) exhibited one well-defined oxidation peak at pH 1, while remaining pesticides gave one reduction peak at pH 13. Adsorptive stripping voltammetric determination of above-said pesticides was developed on the same modified system and lowest detection limits were achieved. The proposed analytical procedure was applied to natural water samples spiked with the selected pesticides to validate the developed stripping procedure. Foi construído um eletrodo baseado em eletrodo de carbono vítreo modificado por um filme de nanotubos de carbono de paredes múltiplas ((MWCNTs)/poli(3-metil tiofeno, P3MT), que foi usado na determinação diferentes classes de pesticidas por voltametria de redissolução de onda quadrada. Inclui-se herbicidas (isoproturon), inseticidas (voltage, cipermetrina, deltametrina, fenvalerato), e acaricidas (dicofol). O comportamento eletroquímico dos pesticidas selecionados foi investigado na superfície do nanocomposito P3MT/MWCNT/GCE, em pH 1, 4, 7, 9,2 e 13. Os voltamogramas cíclicos do isoproturon (ISO) e voltage (VOL) exibiram picos de oxidação bem definidos em pH 1, enquanto os outros exibiram pico de redução em pH 13. A determinação por voltametria de redissolução de onda quadrada dos pesticidas acima citados foi desenvolvida no mesmo sistema modificado e baixos limites de detecção foram obtidos. O procedimento analítico proposto foi aplicado em águas naturais aditivadas com os pesticidas selecionados para validar o procedimento desenvolvido.

A seed induced chemical oxidative polymerization was used for the preparation of pure poly(2-amino thiophenol) nanodiscs (P2AT-NDs (P)). Two templates, (hard (MCM-41) and soft (β-napthalene sulfonic acid), were utilized for the preparation of the seed, P2AT nanostructures loaded MCM-41. The field emission scanning electron microscopy reveals nanodisc morphology for P2AT (P). X-ray diffraction, current-potential characteristics and electrochemical impedance spectroscopy were used to evaluate the physicochemical properties of P2AT-ND (P). The P2AT-ND (P) exhibits semicrystalline behaviour, good electron transport and lesser charge transfer resistance at the interface as compared to simple P2AT prepared by conventional chemical route.

Fabrication of nano size poly(3,4-ethylenedioxythiophene)/multiwalled carbonnanotubes film on a glassy carbon electrode (PEDOT/MWCNT/GCE) in the presence of anionic and cationic surfactants is reported. The modified composite electrodes were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies. SEM studies confirmed the formation of nano size film on the working electrode. Electroanalytical studies were carried out using the above prepared electrode by cyclic voltammetry (CV) and differential pulse stripping voltammetry (DPSV). This electrode exhibited higher sensitivity towards the reduction of cypermethrin (CYP), deltamethrin (DEL), fenvalerate (FEN) falling under pyrethroids family and an organochlorine pesticide dicofol (DCF). In CV, all the selected pesticides were found to exhibit one well-defined irreversible reduction peak at pH 13. Optimum conditions for DPSV were experimentally determined by varying several parameters. The practical application of the newly developed sensor was affirmed by quantification of the selected pesticides in spiked water samples.

The electroactive copolymer of diphenylamine (DPA) and 4,4′-diaminodiphenyl sulfone (DADPS) was synthesized electrochemically in 4 M H2SO4 and ethanol medium. Both electrochemical synthesis and characterization of the copolymer deposited on a glassy carbon electrode (GCE) were carried out using cyclic voltammetry. The voltammograms exhibited different patterns of behavior with different feed concentrations of DPA. Equimolar concentrations of DPA and DADPS demonstrated very efficient growth of the copolymer film on the surface of the GCE. The copolymer exhibited high solubility in dimethyl sulfoxide (DMSO). The scan rate exerted little-effect on this GCE copolymer film, revealing the film's excellent electroactive adherent properties. The effect of pH on the copolymer film showed that the polymer was electrochemically active up to pH 7.0. Spectroelectrochemical analysis of the copolymer film, carried out on an indium tin oxide (ITO) plate, showed multicolor electrochromic behavior when the applied potential was changed. The copolymer was characterized by FTIR and 1H NMR spectral data. The surface morphology was studied using SEM analysis, the grain size of the copolymer was measured using XRD studies and was found to be 56 nm. The electrical conductivity of the copolymer was 2.65 × 10−2 S cm−1, as determined using a four-probe conductivity meter.

4, 4′-Diaminodiphenyl sulphone was polymerized (with lithium/cobalt/lithium–cobalt salts) by chemical oxidation method using potassium perdisulphate. The solubility of the chemically prepared polymer–metal nanocomposite was ascertained and it showed good solubility in DMF, chloroform, trichloroethylene and DMSO. The PDDS–Li/Co/Li–Co nanocomposites were characterized by UV–vis and FTIR spectral studies. Amine and imine vibrations observed at 1593 and 1503 cm −1 were shifted to lower wave numbers when the polymer–metal composites were formed. A single absorption peak due to the N–H stretching vibration of the imino groups of polymer–metal nanocomposite is observed around 3459 cm −1 and it suggests the participation of NH group during polymerization. The X-ray diffraction studies revealed the formation of nano sized (82 nm) crystalline polymer. The conductivity of the PDDS–Li–Co nanocomposite was determined to be 6.26 × 10 −2 S cm −1 . SEM analysis showed mixed granular nature of the polymer–metal nanocomposite. The capacitance (159.04 μF) of chemically synthesized PDDS–Li–Co nanocomposite is suggested as a potential capacitive material.

An electrochemical sensor was developed by modifying a glassy carbon electrode (GCE) with functionalized multiwalled carbon nanotubes (FMWCNTs). The fabricated electrode was used to examine the redox behavior of carbendazim (CAR) in different pH solutions (pH 1.0–13.0). Surface morphology of the modified film was studied by scanning electron microscopy (SEM). An electroanalytical procedure for the determination of CAR was developed by adsorptive differential pulse stripping voltammetry (DPSV) over the range 0.01–5 × 104 µ g L−1. The developed procedure was also validated in real samples such as soil and water samples, and the applicability of the reported method is highly encouraging.

We report the large scale preparation of nanostructured polyaniline-Pd nanoparticles composites (designated as PANI(NS)-PdNPs) through a "seed" induced bulk polymerization. Initially, a small quantity of PANI(NS)-PdNPs was formed inside the cavities of MCM-41 and used as the "seed" for the bulk preparation of PANI(NS)-PdNPs composite. For a comparative purpose a PANI-PdNPs composite was also prepared in the absence of the seed. FESEM image of PANI(NS)-PdNPs composite (bulk) shows nanofibrillar morphology. Further, transmission electron microscopy reveals the presence of spherical Pd nanoparticles. PANI(NS)-PdNPs composite (bulk) showed a good catalytic activity towards reduction of 4-nitrophenol.

The electrochemical copolymerization of aniline (ANI) with 1-amino-9,10-anthraquinone (1-AAQ) was carried out in 4 M sulfuric acid by potential cycling in the potential range of −0.1 V to 1.3 V vs. SCE. Copolymer films were grown from different feed ratios of ANI and 1-AAQ (0.2:0.8, 0.4:0.6, 0.5:0.5, 0.6:0.4, 0.8:0.2) on a glassy carbon electrode (GCE). Studies on the effect of scan rate on the conductivity of the copolymer film confirmed the formation of a stable conducting copolymer film. The FTIR spectrum recorded for the copolymer film provides concrete evidence of copolymer formation, since it indicates the presence of quinone units in the copolymer backbone. XRD data (particle size: 47 nm) and SEM (grain size: 100 nm) micrographs provide a clear picture of the nano-sized polymeric particles formed. It is envisaged that the newly reported copolymer could be a useful material for performing the catalytic reduction of oxygen in an acidic medium—a useful process for fuel cell applications.

An exciting methodology for the electrosynthesis of poly(o-chloroaniline) is proposed, based on the electrochemical polymerisation of o-chloroaniline (OCA) on a polyaniline-modified electrode and copolymerisation of OCA with different compositions of biologically important 4,4′-diaminodiphenylsulfone (DDS) on the same electrode. The copolymer electrosynthesised from an equimolar feed composition of OCA and DDS behaved the best among the other compositions employed for polymerisation. The UV-visible and Fourier transform infrared spectral data obtained for this copolymer suggest the incorporation of DDS in the polymer chain. The X-ray diffraction profile of the copolymer indicates a substantial amorphous nature of the as-synthesised copolymer. Scanning electron micrographs recorded for the homo- and copolymer reveal distinctly different morphologies. The average grain size of the prepared copolymer as approximated from the micrographs is 80 nm. The procedure reported is found to be a very efficient method for electrochemically polymerising pristine OCA and poly(OCA-co-DDS) and the adopted strategy is the best so far reported for the electrochemical polymerisation of OCA on any electrode surface. Copyright © 2009 Society of Chemical Industry