Insight into ion dynamics in a NaClO4-doped polycaprolactone solid polymer electrolyte for solid state batteries.

Employing low Tg polymers has fundamental limitations in providing the desirable ionic conductivity at ambient temperature due to the freezing of chain dynamics. The stiffening of polymer chains and the formation of highly ordered systems due to the crosslinks have influenced the ionic conductivity. Ionic conductivity of 1.02 × 10-5 S cm-1 was attained for the system that presented a quantum mechanical tunnelling mode of ion transport. A Na-ion transference number of 0.31 was achieved for 30 wt% of NaClO4 salt in a polycaprolactone (PCL) matrix with an electrochemical stability window of 3.6 V at 25 °C. High crystallinity and limited availability of free Na+ ions in the electrolyte have resulted in lower ionic conductivity. PCL-NaClO4 exhibited brilliant thermal stability and mechanical properties. The influence of cathode materials MnO2, V2O5 and I2 on the discharge characteristics of an electrochemical cell in the configuration cathode |(70 wt%)PCL-NaClO4(30 wt%)|Na has been studied.

Study on Photophysical Properties of N-Arylphthalamic Acid Derivative Containing 1, 2, 4-Triazole Scaffold.

A novel N-arylphthalamic acid derivative, 2-({4-[(1H-1,2,4-triazol-1-yl)methyl]phenyl}carbamoyl)benzoic acid (TMPCB) was synthesized and their absorption and emission spectra were recorded in fifteen different solvents of varying polarities at room temperature. Ground state dipole moment of the derivative was calculated experimentally by Guggenheim method and solvatochromic approach proposed by Bilot-Kawski. The singlet excited state dipole moment of TMPCB were calculated experimentally based on different approaches of solvent polarity function proposed by Lippert-Mataga, Bakhshiev, Kawskii-Chamma-Viallet, Reichardt and Bilot-Kawski. Singlet excited state dipole moment was greater than ground state dipole moment in all the approaches which could be attributed to considerable π- electron density redistribution. Multiple Linear Regression (MLR) analysis based on Kamlet-Abboud-Taft and Catalan parameters were also studied to correlate solvatochromism and influence of solvents with absorbance and emission spectra. Ground and singlet excited state optimizations of the molecule were also performed using Gaussian 09 W software. HOMO-LUMO energies of the phthalamic acid derivative have been obtained using TD-DFT/PCM (B3LYP/6-31G (d, p)) computations and experimentally by using cyclic voltammetry. Mulliken charges and molecular electrostatic potential plot have also been generated from DFT calculations to identify nucleophilic and electrophilic sites of TMPCB.

Recent advances in carbon nanotubes-based biocatalysts and their applications.

Enzymes have been incorporated into a wide variety of fields and industries as they catalyze many biochemical and chemical reactions. The immobilization of enzymes on carbon nanotubes (CNTs) for generating nano biocatalysts with high stability and reusability is gaining great attention among researchers. Functionalized CNTs act as excellent support for effective enzyme immobilization. Depending on the application, the enzymes can be tailored using the various surface functionalization techniques on the CNTs to extricate the desirable characteristics. Aiming at the preparation of efficient, stable, and recyclable nanobiocatalysts, this review provides an overview of the methods developed to immobilize the various enzymes. Various applications of carbon nanotube-based biocatalysts in water purification, bioremediation, biosensors, and biofuel cells have been comprehensively reviewed.

Electrochemical sensing of vitamin B12 deficiency marker methylmalonic acid using PdAu-PPy tailored carbon fiber paper electrode.

Vitamin B12 is very important for human metabolism and its deficiency can cause anemia and the production of large red blood cells. An increased concentration of methylmalonic acid (MMA) is detected much before the transformation of blood cells, which thereby is an early indicator for mild or serious Vitamin B12 deficiency. A simple electrochemical sensor based on Palladium-Gold (PdAu) was developed by electrodeposition of PdAu nanoparticles on Polypyrrole (PPy) modified carbon fiber paper (CFP) electrode. The modified electrodes were characterized by High resolution transmission electron microscopy (HRTEM), Field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electroanalytical techniques. Differential Pulse Voltammetric (DPV) studies have established that under optimum conditions, the developed sensor exhibits a broad linear dynamic range (4.01 pM - 52.5 nM) with a very low detection limit (1.32 pM). The proposed method was effectively applied in the non-enzymatic determination of MMA at an ultralow level in human blood serum and urine samples. The method displayed high selectivity toward MMA in the presence of other interfering substances.

Electrocatalytic oxidation of morin on electrodeposited Ir-PEDOT nanograins.

Nanoclusters of Ir were electrochemically deposited on carbon fiber paper (CFP) substrate modified with poly(3,4-ethylenedioxythiophene) (PEDOT), a conducting polymer between the potential range 0.0 V and 0.6 V at 0.05 V/s scan rate. The electrocatalytic activity of Ir-PEDOT/CFP electrode towards oxidation of morin, a flavonoid was significantly greater than that of PEDOT/CFP and bare CFP electrodes. Factors affecting the anodic peak of morin namely, effect of pH, scan rate and number of cycles were optimized. The electrochemical route involved adsorption controlled and irreversible processes. Under optimal conditions, the linear dynamic range for the determination of morin was found to be 0.12 nM-2.80 nM. The significantly low detection limit (42.18 pM) demonstrates the ultrasensitivity of the proposed method. The reliability of the method was evaluated for the quantification of morin present in mulberry leaves, guava leaves and grape wine.