Profiling of trace elemental impurities in caustic soda matrix by inductively coupled plasma mass spectrometric technique.

An inductively coupled plasma mass spectrometric (ICP-MS) technique method is developed for simultaneous determination of Li, Cr, Mn, Fe, Ni, Co, Cu, Sr, Ag, Cd, Ba, and Pb at trace level in caustic soda. Operational parameters of the instrument were optimized and suitable accessory (argon gas dilution) was used in the method. Direct aspiration of high total dissolved solids (TDS) samples (beyond 0.2% TDS) and highly alkaline NaOH is not suitable for the instrument; therefore, strategy of neutralization of NaOH by HNO3 was adopted to handle its high alkalinity. Suitable internal standards of low, mid, and high atomic masses were used with external calibration. Features such as matrix matching, calibration verification, interference correction, etc. were undertaken in this work. Neutralized caustic soda samples were spiked with the analytes with lower, middle, and higher concentration. The results of spiking with 30, 70, 140, and 200 ppb were examined. The method exhibited excellent accuracy and precision.

Correlating growth mechanism and morphology in Cu-TCNQ organometallic complex: A microscopic study.

The structure-property correlation in the Cu-TCNQ organometallic complex is very important for explaining its unusual electrical, optical and magnetic properties. Consequently several morphological studies and their correlation with the properties of these materials can be found in the literature, although no systematic study of various morphologies with growth conditions and their correlation has been reported to the best of our knowledge. Therefore in this manuscript the interconversion of various morphologies is reported using electron and probe microscopies. A conventional Cu TEM grid acted as the copper source to form a Cu-TCNQ complex and the complex, which formed at the surface of the TEM grid. The complex thus prepared was characterized by FTIR and Raman spectroscopic techniques. The shifting of ̵-CN from 2221 cm-1 (TCNQ) to 2201 cm-1 indicates formation of a complex and the identical nature of IR spectra in two phases indicates that they are polymorphs. The morphologies of Cu-TCNQ were followed through FE-SEM and TEM studies. Various morphologies such as needle, square tube, platelet etc. were observed as a function of time. A distinct transition from needle to platelet morphology was observed as the complex grew. The conductance of various morphologies in phase-I as well as phase-II were also measured and compared by Spreading Resistance Imaging (SRI) at different bias voltage i.e. 1 V, 3 V and 5 V.

Fluorescent carbon nanoparticles obtained from charcoal via green methods and their application for sensing Fe3+ in an aqueous medium.

Two green methods (microwave and hydrothermal) were employed for the preparation of water dispersible fluorescent carbon nanoparticles (CNPs) from activated charcoal. Microwave and hydrothermally synthesized carbon nanoparticles, (MW-CNPs) and (HT-CNPs), respectively were characterized by microscopic and spectroscopic techniques. A detailed study of their fluorescence characteristics was made. MW-CNPs and HT-CNPs were tested for metal ion selectivity in aqueous medium. MW-CNPs showed selectivity for Fe3+ among the tested metal ions and important studies such as for interference, linear range and limit of detection were carried out. The application of MW-CNPs for detection of Fe3+ in water was demonstrated.

Fluorescence characteristics of carbon nanoemitters derived from sucrose by green hydrothermal and microwave methods.

In this work, fluorescent carbon nanoparticles (CNPs) were prepared through two green methods i.e. microwave and hydrothermal, using sucrose as carbon precursor. Both of these methods have offered fluorescent CNPs as characterized by TEM, FTIR, zeta potential, absorbance and emission techniques. Excitation dependent emission spectra were exhibited by aqueous dispersion of these CNPs when they were subjected to different excitation wavelengths. The luminous characteristics of CNPs obtained from both of these methods were studied and compared. Their fluorescence stability in water and buffer was monitored for about three months. Influence of pH and various metal ions on emission spectra were investigated.

Colorimetric and fluorogenic recognition of Hg2+ and Cr3+ in acetonitrile and their test paper recognition in aqueous media with the aid of rhodamine based sensors.

Two new rhodamine derivatives (L1 and L2) were synthesized, characterized and their ion recognition property has been investigated. Both of the ionophores exhibit colorimetric and fluorogenic response for Hg(2+) and Cr(3+) ions among large number of alkali, alkaline earth and transition metal ions tested in acetonitrile. Detail studies on determination of binding constant, binding mode, reversibility of binding, lower detection limit have been carried out. Detection of metal ions in aqueous media has also been demonstrated by preparation of simple, convenient and disposable test paper sensors with two approaches viz. filter paper and membrane filter loaded with these ionophores. Both of these methods responded sharply to both the metal ions (Hg(2+) and Cr(3+)) in aqueous solution, detectable by bared-eye. For better sensing at low concentration of metal ions, reprecipitation followed by filtration enrichment of ligands on membrane filter was employed.

Effective management of passive layers using composite cathodes in solid state magnesium batteries.

A simple and effective method for the management of the passive layer in solid state batteries is reported. The success is achieved using a composite cathode with embedded channels of polyaniline allowing smooth charge transfer across the passive layer. The composite cathode manifested better performance in terms of the cell characteristics and shelf life.