Syed Ashfaq Nabi

Synthesis, Characterization, and Analytical Applications of a New Composite Cation Exchange Material Acetonitrile Stannic(IV) Selenite: Adsorption Behavior of Toxic Metal Ions in Nonionic Surfactant Medium

A composite cation exchange material acetonitrile stannic(IV) selenite was prepared under different experimental conditions. The ion exchange capacity of the material was improved from 0.75 to 1.83 meq g−1 in comparison to its inorganic counterpart, stannic selenite. The material was characterized on the basis of X-ray, TGA, FTIR, and SEM studies. Ion-exchange capacity, pH titration, elution behavior, and distribution studies were also carried out to determine the preliminary ion-exchange properties of the material. Furthermore, it was investigated that this ion exchange material has a good reusability after 8 times regeneration. The sorption behavior of metal ions was studied in nonionic surfactants namely triton x-100 and tween. On the basis of distribution coefficient studies, several binary separations of metal ions viz- Pb2+-Th4+, Ni2+-Th4+, Ni2+-Zn2+, Cu2+-Ce4+, Al3+-Bi3+, and Al3+Zn2+ was achieved on the packed column of this ion exchange material. The practical applicability of this cation-exchanger was demonstrated in the separation of Th4+ from a synthetic mixture of Th4+, Ca2+, Sr2+, Ni2+, and Mg2+ as well as Cu2+ and Zn2+ from a brass alloy sample. Thus, all the studies suggest that acetonitrile stannic(IV) selenite has excellent potential for the removal of metal ionic pollutant species from aqueous media effectively.

Synthesis and characterization of nano-composite ion-exchanger; its adsorption behavior

A novel organic-inorganic nanocomposite cation-exchanger has been synthesized via sol-gel method. It was characterized on the basis of FTIR, XRD, SEM, TEM, AFM and Raman studies. The structural studies reveal semi-crystalline nature of the material with the particle size ranging from 1-5 nm. Physiochemical properties such as ion-exchange capacity, chemical and thermal stability of composite material have also been determined. Bifunctional behavior of the material has been indicated by its pH titrations curves. The nanocomposite material exhibits improved thermal stability, higher ion-exchange capacity and better selectivity for toxic heavy metals. The ion-exchange material shows an ion-exchange capacity of 1.8 meq g(-1) for Na(+) ions. Sorption behavior of metal ions on the material was studied in different solvents. The cation exchanger was found to be selective for Pb(II), Hg(II) and Zr(IV) ions. The limit of detection (LOD) and the limit of quantification (LOQ) for Pb(II) ion was found to be 0.85 and 2.85 μg L(-1). Analytically important separations of heavy metal ions in synthetic mixtures as well as industrial effluents and natural water were achieved with the exchanger. The practical utility of polyanilineZr(IV)sulphosalicylate cation exchanger has been established for the analysis and recovery of heavy metal ions in environmental samples.

Synthesis, characterization, antimicrobial activity and applications of polyanilineTi(IV)arsenophosphate adsorbent for the analysis of organic and inorganic pollutants

A novel polyaniline based composite cation exchange material has been synthesized by simple chemical route and characterized on the basis of sophisticated techniques. XRD and SEM analyses reveal the amorphous morphology of the material. The partition coefficient studies of different metal ions on the material were performed in DMW and diverse concentrations of HClO4 solutions. On the basis of high Kd values some significant separations of heavy toxic metal ions were achieved from synthetic mixtures as well as tap water samples by using columns of this exchanger. For the optimum adsorption of dye on the material, the effect of various parameters along with Langmuir and Freundlich adsorption isotherm were examined. The observed result of conducting measurement indicates that the material covers semiconductor range. The photochemical degradation of industrial dyes and antimicrobial activity were also investigated which show significant results than some of the known antibiotics. On the basis of good ion exchange capacity along with photochemical degradation and microbial activity, polyanilineTi(IV)arsenophosphate can be considered as an excellent conducting material for the treatment metal ions and degradation of organic pollutants.

Synthesis and ion-exchange properties of thermally stable stannic selenite.

Stannic selenites have been synthesized under a variety of conditions. The most stable sample is prepared by mixing 0-0.5M solutions of stannic chloride and sodium selenite in the ratio of 1:1 at pH 1. It is a bifunctional amorphous material. A tentative structure has been proposed on the basis of chemical composition, pH titrations, infrared and thermogravimetric analyses. Its ion-exchange capacity is 0.75 and 0.73 meq g after drying at 50 degrees and 500 degrees respectively. Its analytical importance has been established by the following quantitative separations: Cu(2+) from Ni(2+), Co(2+), Fe(3+), Ga(3+) and In(3+), Fe(3+) from Pb(2+) and Sc(3+), and Sc(3+) from VO(2+).

Comparative study of titanium(IV)-based exchangers in aqueous and mixed solvent systems

The antimonate, arsenate, tungstate, molybdate and selenite of titanium have been synthesized. Their composition and chemical and thermal stability have been determined. Effects of pH and temperature on ion-exchange capacity have been studied. Titanium antimonate was found to be the most stable. The utility of these ion-exchangers for analytical separations was examined by determining the distribution coefficients for 26 metal ions in some aqueous, non-aqueous and mixed solvent systems. Quantitative separations of HgCd, PbCu and PbZn have been achieved on titanium tungstate columns, and LaBa mixtures have been separated on a titanium arsenate column.

Investigation of the electrical conductivity and optical property of polyaniline-based nanocomposite and its application as an ethanol vapor sensor

Polyaniline–Sn(IV)iodophosphate (PANI–SnIP) nanocomposite cation exchanger was synthesized via the sol–gel approach and its AC and DC electrical conductivity, dielectric properties and optical properties were studied. The characterization of the nanocomposite using FT-IR, UV-Vis spectroscopy, SEM and TEM showed the formation of a nanocomposite with improved physicochemical properties. The AC electrical conductivity was found to increase with the increase in applied frequency and concentration of the Sn(IV)iodophosphate (SnIP) filler content. The optical band gap of the nanocomposite decreased from 3.99 eV for pure polyaniline (PANI) to 3.60 eV for the nanocomposite with 30% SnIP content. The ethanol vapor sensing characteristics were evaluated by the fabrication of a PANI–SnIP nanocomposite as a sensor for ethanol vapor detection. The sensing performance of the nanocomposite was markedly improved with the increase of SnIP concentration. The nanocomposite sensor exhibited a linear response to the variable concentration of ethanol (50, 100, 300, and 500 ppm), a quick response time, and a reproducible and reversible response, which are a clear manifestation of its sensing ability and environmental utility.

Synthesis, characterization and analytical application of hybrid; Acrylamide zirconium (IV) arsenate a cation exchanger, effect of dielectric constant on distribution coefficient of metal ions

A new hybrid inorganic-organic cation exchanger acrylamide zirconium (IV) arsenate has been synthesized, characterized and its analytical application explored. The effect of experimental parameters such as mixing ratio of reagents, temperature, and pH on the properties of material has been studied. FTIR, TGA, X-ray, UV-vis spectrophotometry, SEM and elemental analysis were used to determine the physiochemical properties of this hybrid ion exchanger. The material behaves as a monofunctional acid with ion-exchange capacity of 1.65 meq/g for Na(+) ions. The chemical stability data reveals that the exchanger is quite stable in mineral acids, bases and fairly stable in organic solvents, while as thermal analysis shows that the material retain 84% of its ion-exchange capacity up to 600 degrees C. Adsorption behavior of metal ions in solvents with increasing dielectric constant has also been explored. The sorption studies reveal that the material is selective for Pb(2+) ions. The analytical utility of the material has been explored by achieving some binary separations of metal ions on its column. Pb(2+) has been selectively removed from synthetic mixtures containing Mg(2+), Ca(2+), Sr(2+), Zn(2+) and Cu(2+), Al(3+), Ni(2+), Fe(3+). In order to demonstrate practical utility of the material quantitative separation of the Cu(2+) and Zn(2+) in brass sample has been achieved on its columns.

A New Hybrid EDTA–Zirconium Phosphate Cation-Exchanger: Synthesis, Characterization and Adsorption Behaviour for Environmental Monitoring

EDTA–zirconium phosphate has been synthesized as a new amorphous hybrid cation-exchanger by the combination of the inorganic ion-exchanger zirconium phosphate and EDTA, thereby providing a new class of organic–inorganic hybrid ion-exchanger with better mechanical and granular properties, a good ion-exchange capacity (2.40 mequiv/g dry exchanger for Na+), good reproducibility, and a higher stability and selectivity towards heavy metal ions. It has been characterized using FT-IR, TGA/DTA, X-ray and SEM methods, in addition to ion-exchange studies such as the determination of its ion-exchange capacity, elution and distribution behaviour, to provide a better understanding of the ion-exchange behaviour of the material. On the basis of distribution studies, the material was found to be highly selective towards Th(IV) and its selectivity was examined by achieving some important binary separations such as Cd(II)–Th(IV), Ni(II)–Th(IV), Hg(II)–Th(IV), Zn(II)–Th(IV), Pb(II)–Th(IV) and Al(III)–Th(IV) by column means, indicating its utility in environmental pollution control in one way or other.

Synthesis, characterization, photolytic degradation, electrical conductivity and applications of a nanocomposite adsorbent for the treatment of pollutants

A new semi-crystalline nanocomposite cation exchanger has been synthesized by the sol–gel method and characterized on the basis of FTIR, XRD, SEM, TEM, TGA and CHNO analysis. The ion-exchange material was synthesized at pH 1.0 and shows an ion exchange capacity of 1.37 meq g−1 for Na+ ions. The composite material exhibits improved ion exchange capacity along with chemical and thermal stability. It can be used at up to 300 °C, with 98% retention of its initial ion-exchange capacity. The conductivity of different samples of composite material was found to be in the semiconducting range, which indicates that the conductivity of the samples is highly dependent on the % of inorganic precipitate. The photochemical degradation of industrial dye was also investigated using this composite. The distribution coefficient studies of metal ions on the material were performed in different concentrations of surfactants (Tween 80, CPC) and on mixtures (solvent + surfactant). On the basis of Kd values the material was found to be selective for Hg(II), Bi(III), Zr(IV) and Pb(II) ions. Some analytically important separations of metal ions in synthetic mixtures and real samples were achieved on the column of this exchanger. The limits of detection for Pb(II), Zn(II) and Hg(II) were found to be 0.32, 0.92 and 0.50 μg L−1 and the limits of quantification were found to be 1.07, 3.08 and 1.69, respectively. Besides the ion-exchanger, polyaniline Ti(IV)As composite material has been successfully applied for the photochemical degradation of industrial dye as well as a conducting material.

Synthesis and characterization of a new cation exchanger-zirconium(IV)iodotungstate: Separation and determination of metal ion contents of synthetic mixtures, pharmaceutical preparations and standard reference material

Samples of zirconium(IV)iodotungstate have been synthesized under varying mixing order and ratios of aqueous solution of potassium iodate, sodium tungstate and zirconium oxychloride at pH 1. A tentative formula was proposed on the basis of chemical composition, FTIR and thermogravimetric studies. The material shows a capacity of 0.68 meq g(-1) (for K+) which can be retained up to 200 degrees C. pH titration data reveal its monofunctional behavior. The distribution coefficient values of metal ions have been determined in various solvent systems. A number of important and analytically difficult quantitative separations of metal ions have been achieved using columns packed with this exchanger. In order to demonstrate practical utility of this material, Hg2+ and Pb2+ have been selectively separated and determined in the synthetic mixtures. Assay of Al3+ and Mg2+ in commercial tablets and analysis of lead in the standard reference material have also been attempted.