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Mishra M.K.,Sambalpur University | Moharana S.,Sambalpur University | Dash B.,CSIRInstitute of Minerals and Materials Technology | Mahaling R.N.,Sambalpur University
Polymer Science - Series A | Year: 2017

In the present work a series of poly(vinylidene fluoride)/BiFeO3/poly(ethylene glycol) composite films were prepared by solvent casting method with poly(vinylidene fluoride) as polymer matrix, bismuth ferrite as ceramic filler and poly(ethylene glycol) as binding agent as well as enhancer. The structural analysis of the composite films by X-ray diffraction confirms that the composites have a distorted rhombohedral structure. The micro-structural analysis shows that the use of poly(ethylene glycol)in the composite films enhances the homogeneity as well as compatibility of BiFeO3 particles within the poly(vinylidene fluoride) matrix. The dielectric and electrical study done by impedance analyzer reveals that with an increase in poly(ethylene glycol) concentration, there is a subsequent increase in dielectric constant as well as AC electrical conductivity. Finally, the ferroelectric behavior of the composite confirms that the ferroelectric properties of the composites are enhanced by the addition of BiFeO3 with an increase in poly(ethylene glycol) concentrations. These preliminary results give an idea for possible applications of this type of composites in the field of electronic applications. © 2017, Pleiades Publishing, Ltd.

Priyadarshini E.,Academy of Scientific and Innovative Research | Pradhan N.,Academy of Scientific and Innovative Research | Pradhan N.,CSIRInstitute of Minerals and Materials Technology
Sensors and Actuators, B: Chemical | Year: 2017

Rapid and high precision detection of toxic metal ions is one of the chief requirements today to combat environment pollution. Gold nanoparticles play a key role in this by assisting the development of smart sensors and detection agents. Their high surface to volume ratio and unique optical property facilitates the development of high sensitive analytical GNP based bio-sensing tools. Recently, a major research thrust area has been the design and development of smartly fabricated GNPs as probes for selective detection of toxic contaminates and metal pollutants. In this review we focus on the use of GNPs and its functionalization for colorimetric detection of metal ions. Colorimetric detection enables cost effective and simple monitoring of toxic ions accompanied with the advantages of on-site applicability, avoids complex instrumentation, ease of analysis and usage. We also discuss the promising prospects and future potentiality of GNPs to serve as next generation multi-functional sensing tools and “lab-on-chip” detection agents. © 2016

Mahesh M.,CSIRCentral Leather Research Institute CLRI | Arivizhivendhan K.V.,CSIRCentral Leather Research Institute CLRI | Maharaja P.,CSIRCentral Leather Research Institute CLRI | Boopathy R.,CSIRInstitute of Minerals and Materials Technology | Sekaran G.,CSIRCentral Leather Research Institute CLRI
Journal of Molecular Catalysis B: Enzymatic | Year: 2016

The fungal strain Aspergillus ibericus was isolated from food waste for the production of pectinase. In this study response surface methodology (RSM) was employed to determine optimum conditions for the production of pectinase from citrus pectin. The optimum conditions for the production of pectinase were found to be pH, 4.0; temperature, 40 °C; incubation time, 120 h and substrate concentration (Citrus Pectin), 2% (w/v). The maximum activity of pectinase at optimum conditions was found to be 69.9 U mL−1. The purification by DEAE-Cellulose increased the specific activity of pectinase by about 10.1 fold from 64 to 650 U mg−1 protein. The molecular weight of the purified pectinase was found to be 41 kDa and 43 kDa. The purified pectinase was immobilized onto functionalized nanoporous activated carbon (FNAC), the maximum immobilization capacity of pectinase onto FNAC was found to be 3360 U g−1 at optimum immobilization conditions; time, 150 min; pH, 5.0; temperature, 35 °C and initial concentration of pectinase, 52 × 103 U (80 mg) L−1. The immobilized pectinase showed better thermal and storage stability than free pectinase. The immobilization of pectinase onto FNAC obeyed the Freundlich isotherm model. The immobilization of pectinase onto FNAC was confirmed by FT-IR, XRD, TGA, DSC and SEM analyses. The pectinase immobilized FNAC packed bed column reactor was used for the treatment of pectin containing wastewater under continuous mode. The maximum treatment efficiency for citrus pectin in synthetic wastewater was observed to be 82% at operating conditions: Hydraulic retention time, 180 min; pH, 5.0 and citrus pectin concentration 1% (w/v). Further, the citrus processing industrial wastewater was treated in pectinase immobilized FNAC packed bed column reactor and the system showed 94% of pectin treatment. The treatment of pectin in wastewater obeyed pseudo second order rate kinetic treatment model. The treatment of pectin in wastewater was confirmed by UV–vis spectroscopy and FT-IR spectrophotometer analyses. © 2016 Elsevier B.V.

Panda S.,CSIRInstitute of Minerals and Materials Technology | Mishra G.,CSIRInstitute of Minerals and Materials Technology | Sarangi C.K.,CSIRInstitute of Minerals and Materials Technology | Sanjay K.,CSIRInstitute of Minerals and Materials Technology | And 7 more authors.
Hydrometallurgy | Year: 2016

Two ore samples, one obtained from a partially leached heap with suspended operations for about four years and the other through sonic drilling of a discarded dump were tested for the amenability/feasibility of copper extraction through reactor and column leaching. Mineralogical analysis of the samples indicated the dominant sulphide minerals to be chalcopyrite and pyrite. Various process parameters such as the effect of acid concentration, time, oxidant, pulverization and temperature were studied for the reactor leaching experiments. A maximum of 91% Cu extraction can be achieved while leaching the pulverized sonic drilled sample at 90 °C for 3 h. On the other hand, column leaching studies at 1 kg scale showed 65–70% Cu extraction with an acid concentration of 2.7% (v/v) for both the samples. Sequential leaching of the chemically leached residues of both sonic drilled and heap leached pad sample yielded additional 13.2% and 22.2% Cu, respectively in 20 days of bacterial leaching using a mixed culture of meso-acidophilic bacterial consortium. Column leaching studies showed that the heap leached pad sample was more amenable to leaching than the sonic drilled one. Further, during the downstream processing of the leach liquors, the solvent extraction efficiency was about 95% and the Cu metal deposited by electrowinning was of 99.9% purity. A tentative process flowsheet for the recovery of copper was also prepared. © 2015 Elsevier B.V.

Pradhan A.K.,Academy of Scientific and Innovative Research | Pradhan A.K.,CSIRInstitute of Minerals and Materials Technology | Pradhan N.,Academy of Scientific and Innovative Research | Pradhan N.,CSIRInstitute of Minerals and Materials Technology | And 4 more authors.
Applied Biochemistry and Biotechnology | Year: 2014

Two different microbial biosurfactants S9BS and CHBS were isolated from Lysinibacillus fusiformis S9 and Bacillus tequilensis CH. Cytotoxicity effect of these biosurfactants on human embryonic kidney cancerous cell (HEK-293) were studied with the help of 3-(4,5-dimethylthiazol-2yl-)-2, 5-diphenyl tetrazolium bromide (MTT) assay and morphological changes were observed under inverted microscope. The biosurfactants exhibited positive cytotoxic effect on HEK-293 cell line. It was found that LC50 of S9BS and CHBS were 75 and 100 μg ml−1, respectively. Further cell cycle and apoptosis analysis of biosurfactant-treated HEK-293 cell line were done by FACS. In this study, cytotoxic effect of glycolipid biosurfactant against HEK-293 cell lines is reported for the first time. Mechanism towards increased membrane permeability of biosurfactant-treated cancer cell may be the incorporation of its lipid moiety into the plasma membrane leading to formation of pores and membrane disruption. Hence, these microbial biosurfactants can prove to be significant biomolecule for cancer treatment. © 2014, Springer Science+Business Media New York.

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