Focused Ion Beam Tomography

To study the fundamental effect of shape and morphology of any material on its properties, it is very essential to know and study its morphology. Focused ion beam (FIB) tomography is a 3D chemical and structural relationship studying technique. The instrumentation of FIB looks like that of the scanning electron microscopy (SEM), but there is a major difference in the beam used for scanning. For SEM, a beam of electrons is used with scanning medium whereas in FIB, a much focused beam of ions is used for scanning. FIB can be used for lithography and ablation purposes, but due to advancements and high-energy focused beam, it is nowadays being used as a tomographic technique. Tomography is defined as imaging by sectoring or cross-sectioning any desired area. The hyphenation of FIB with energy-dispersive spectrometry or secondary ion mass spectrometry can give us elemental analysis with very high-resolution 3D images for a sample. This technique contributes to acquaintance of qualitative and quantitative analyses, 3D volume creations, and image processing. In this chapter, we will discuss the advancements in FIB instrumentation and its use as 3D imaging tool for different samples ranging from nanometer (nm)-sized materials to micrometer (μm)-sized biological samples

A Novel Micellar Electrokinetic Chromatographic Method for Separation of Metal-DDTC Complexes

Micellar electrokinetic chromatography (MEKC) was examined for the separation and determination of Mo(VI), Cr(VI), Ni(II), Pd(II), and Co(III) as diethyl dithiocarbamate (DDTC) chelates. The separation was achieved from fused silica capillary (52 cm × 75 μm id) with effective length 40 cm, background electrolyte (BGE) borate buffer pH 9.1 (25 mM), CTAB 30% (100 mM), and 1% butanol in methanol (70 : 30 : 5 v/v/v) with applied voltage of −10 kV using reverse polarity. The photodiode array detection was achieved at 225 nm. The linear calibration for each of the element was obtained within 0.16–10 μg/mL with a limit of detection (LOD) 0.005–0.0167 μg/mL. The separation and determination was repeatable with relative standard deviation (RSD) within 2.4–3.3% (n = 4) in terms of migration time and peak height/peak area. The method was applied for the determination of Mo(VI) from potatoes and almond, Ni(II) from hydrogenated vegetable oil, and Co(III) from pharmaceutical preparations with RSD within 3.9%. The results obtained were checked by standard addition and rechecked by atomic absorption spectrometry

ISSN-1996-918X Pak

Abstract BSOPD, bis(salicylaldehyde) orthophenylenediamine) is investigated as complexing agent in capillary electrophoresis for determination of gold and chromium. BSOPD was chosen as the UVVisible absorbing chelating ligand because of its ability to form stable complexes with metal ions. Both the metal ions can be determined in single run under optimized conditions with run time of 12 minutes including coexisted ions usually present in waste water. Separation was achieved at optimized conditions of 50 mM phosphate buffer as a background electrolyte at pH =3.4, at applied voltage of -10 kV and detection wavelength of 231 nm. Under above mentioned conditions, limit of quantification (0.5 and 10 µg mL -1 ) and detection limit (0.1667 and 3.33 µg mL -1 ) were found for Au(III) and Cr(VI), respectively. Linear calibration graphs were obtained 0.5 -50 µg mL -1 for Au(III) and 10 -60 µg mL -1 for Cr(VI) with the correlation coefficient value 0.996 and 0.993, respectively. Utility of this method for metal analysis has been investigated by determining gold from wastewater samples of goldsmith factories and chromium in some environmental waters (portable and polluted).The method was validated by comparing results obtained with capillary zone electrophoresis with atomic absorption spectroscopy

EVALUATION OF BANANA PEEL FOR TREATMENT OF ARSENIC CONTAMINATED WATER

Abstract Arsenic is a highly toxic metal and its moblity in surface water and ground water ar

ISSN-1996-918X Pak

Abstract Banana peel, a common fruit waste has been investigated to remove and preconcentrate Cr(III) from industrial wastewater. It was characterized by FT-IR spectroscopy. The parameters pH, contact time, initial metal ion concentration and temperature were investigated and the maximum sorption was found to be 95%. The binding of metal ions was found to be pH dependent with the optimal sorption occurring at pH 4. The retained species were eluted using 5mL of 2 M HNO 3 . The mechanism for the binding of Cr(III) on the banana peel surface was also studied in detail. The Langmuir and Dubinin-Radushkevich (D-R) isotherms were used to describe the partitioning behavior for the system at different temperatures. Kinetic and thermodynamic measurements of the banana peel for chromium ions were also studied. The method was applied for the removal and preconcentration of Cr(III) from industrial wastewater

Nano-antivirals: A comprehensive review

Nanoparticles can be used as inhibitory agents against various microorganisms, including bacteria, algae, archaea, fungi, and a huge class of viruses. The mechanism of action includes inhibiting the function of the cell membrane/stopping the synthesis of the cell membrane, disturbing the transduction of energy, producing toxic reactive oxygen species (ROS), and inhibiting or reducing RNA and DNA production. Various nanomaterials, including different metallic, silicon, and carbon-based nanomaterials and nanoarchitectures, have been successfully used against different viruses. Recent research strongly agrees that these nanoarchitecture-based virucidal materials (nano-antivirals) have shown activity in the solid state. Therefore, they are very useful in the development of several products, such as fabric and high-touch surfaces. This review thoroughly and critically identifies recently developed nano-antivirals and their products, nano-antiviral deposition methods on various substrates, and possible mechanisms of action. By considering the commercial viability of nano-antivirals, recommendations are made to develop scalable and sustainable nano-antiviral products with contact-killing properties

Chemical Recycling of Expanded Polystyrene Waste: Synthesis of Novel Functional Polystyrene-Hydrazone Surface for Phenol Removal

Expanded polystyrene (EPS) waste was chemically recycled to a novel functional polystyrene-hydrazone (PSH) surface by acetylation of polystyrene (PS) and then condensation with phenyl hydrazine. The synthesized surface was characterized by the FT-IR and elemental analysis. Synthesized novel functional PSH surface was successfully applied for the treatment of phenol-contaminated industrial wastewater by solid-phase extraction. Multivariant sorption optimization was achieved by factorial design approach. 99.93% of phenol was removed from aqueous solution. FT-IR study showed the involvement of nitrogen of hydrazone moiety of synthesized surface for the uptake of phenol through the hydrogen bonding

Utilization of Bis(salicylaldehyde)orthophenylenediamine for the Separation of Gold and Chromium by Capillary Zone Electrophoresis

BSOPD, bis(salicylaldehyde) orthophenylenediamine) is investigated as complexing agent in capillary electrophoresis for determination of gold and chromium. BSOPD was chosen as the UV-Visible absorbing chelating ligand because of its ability to form stable complexes with metal ions. Both the metal ions can be determined in single run under optimized conditions with run time of 12 minutes including coexisted ions usually present in waste water. Separation was achieved at optimized conditions of 50 mM phosphate buffer as a background electrolyte at pH =3.4, at applied voltage of -10 kV and detection wavelength of 231 nm. Under above mentioned conditions, limit of quantification (0.5 and 10 µg mL-1) and detection limit (0.1667 and 3.33 µg mL-1) were found for Au(III) and Cr(VI), respectively. Linear calibration graphs were obtained 0.5 – 50 µg mL-1 for Au(III) and 10 – 60 µg mL-1 for Cr(VI) with the correlation coefficient value 0.996 and 0.993, respectively. Utility of this method for metal analysis has been investigated by determining gold from wastewater samples of goldsmith factories and chromium in some environmental waters (portable and polluted).The method was validated by comparing results obtained with capillary zone electrophoresis with atomic absorption spectroscopy

Enrichment of indium from aqueous solution using functionalized sorbent

1197-1202The present method utilizes styrene-divinylbenzene-based polymeric material containing phthalic acid as chelating agent to concentrate ultra trace amounts of indium ions in aqueous solutions. Sorption behaviour of In(III) ions under static and dynamic conditions onto the new synthetic resin is reported here. Maximum sorption has been achieved from solution with 8 min of agitation time in the pH range 5-8. The lowest concentration for quantitative recovery is 5 ppb with the preconcentration factor 666. The kinetics and thermodynamics of sorption have been studied in detail. The kinetics follows the first order rate equation with the rate constant k, equal to 0.645 ± 0.05 min- l. The variation of equilibrium constant kc with temperature between 10°C to 50°C yields values of ΔH 33.7±1.96 kJmol-1, ΔS 136.9±6.4 Jmol-1K-1 and ΔG303K -7690 ± 200 Jmol-1K-1. The sorption data in the concentration range 5.26×10-6 to 2.19×10-4 M L-1 In(III) ions follow Langmuir, Freundlich, and Dubinin-Radushkevich isotherms at all the temperatures investigated. The sorption of In(III) ions onto the synthesized resin in the presence of common anions and cations has also been measured

Banana Peel: A Green and Economical Sorbent for Cr(III) Removal

Banana peel, a common fruit waste has been investigated to remove and preconcentrate Cr(III) from industrial wastewater. It was characterized by FT-IR spectroscopy. The parameters pH, contact time, initial metal ion concentration and temperature were investigated and the maximum sorption was found to be 95%. The binding of metal ions was found to be pH dependent with the optimal sorption occurring at pH 4. The retained species were eluted using 5mL of 2 M HNO3. The mechanism for the binding of Cr(III) on the banana peel surface was also studied in detail. The Langmuir and Dubinin-Radushkevich (D-R) isotherms were used to describe the partitioning behavior for the system at different temperatures. Kinetic and thermodynamic measurements of the banana peel for chromium ions were also studied. The method was applied for the removal and preconcentration of Cr(III) from industrial wastewater