The Experts below are selected from a list of 4209 Experts worldwide ranked by ideXlab platform
Somenath Mitra - One of the best experts on this subject based on the ideXlab platform.
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carbon nanotube immobilized composite hollow fiber membranes for extraction of Volatile Organics from air
Journal of Physical Chemistry C, 2015Co-Authors: Smruti Ragunath, Somenath MitraAbstract:This paper reports the development of novel carbon nanotube immobilized composite membranes (CNIMs) for the extraction of Volatile Organics from air. The nanotubes were immobilized onto the selective layer of a composite membrane where they served as sorption sites and provided additional pathways for enhanced solute transport. Depending upon the process conditions, the presence of carbon nanotubes led to the organic removal with flux as high as 37.7 × 10–5, 72.9 × 10–5, and 8.22 × 10–5 gm mol/m2 min and an increase in mass-transfer coefficient of about 92.2%, 22.7%, and 44.3% for toluene, dichloromethane, and ethanol, respectively. The CNIMs demonstrated several advantages, including enhanced recovery at low concentrations and low temperature.
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carbon nanotube immobilized composite hollow fiber membranes for pervaporative removal of Volatile Organics from water
Journal of Physical Chemistry C, 2010Co-Authors: Ornthida Saekhow, Somenath MitraAbstract:This paper reports the development of novel carbon nanotube immobilized composite membranes (CNIM) for pervaporative removal of Organics from an aqueous matrix. The nanotubes were immobilized into the pores of a composite, where they served as sorption sites that provided additional pathways for enhanced solute transport, affecting both the partitioning and diffusion through the membrane. Depending upon the process conditions, the enhancement in organic removal and mass transfer rates were higher by 108 and 95%, respectively. The CNIM demonstrated several advantages including enhanced recovery at low concentrations, lower temperatures, and higher flow rates. Overall, these lead to more energy efficient processes.
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preconcentration of Volatile Organics on self assembled carbon nanotubes in a microtrap
Analytical Chemistry, 2005Co-Authors: Chutarat Saridara, Roman Brukh, Zafar Iqbal, Somenath MitraAbstract:This paper reports the self-assembly of carbon nanotubes (CNTs) on the inside wall of a steel capillary to fabricate a microtrap for the adsorption/desorption of trace Organics. The microtrap functioned as a nanoconcentrator and an injector for gas chromatography (GC). The CNTs were deposited as a thin film by catalytic chemical vapor deposition from either CO or C2H4 as the precursor. The sorbent film synthesized from C2H4−CVD (CVD = chemical vapor deposition) had higher CNT density and thus was a stronger sorbent. In general, the CNT microtraps showed high-capacity adsorption and fast quantitative desorption, and the process showed excellent precision. This study demonstrates that CNT films can be deposited quite easily in a steel capillary for use in different analytical applications, and CNT films can perform as efficiently as packed-bed carbon sorbents.
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on line membrane extraction liquid chromatography for monitoring semi Volatile Organics in aqueous matrices
Journal of Chromatography A, 2000Co-Authors: Xuemei Guo, Somenath MitraAbstract:Membrane extraction is an attractive alternative to conventional extraction methods, such as liquid-liquid extraction and solid phase extraction, because the analytes can be isolated in a continuous fashion. On-line detection can be carried out using a suitable analytical instrument. The objective of this study is to study the enrichment of semi-Volatile organic compounds (SVOCs) from an aqueous matrix by on-line membrane extraction, to be followed by liquid chromatographic (ME-LC) analysis for continuous monitoring. The membrane serves as an interface across which liquid-liquid extraction takes place. The SVOCs transfer from the aqueous phase and are concentrated in an organic extractant. The enriched solvent is intermittently injected into an HPLC for analysis. In this paper, the enrichment into the organic phase under different operating conditions and the performance characteristics of the instrumentation are presented.
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development of membrane purge and trap for measurement of Volatile Organics in water
Analytical Letters, 1998Co-Authors: Somenath Mitra, Xuemei GuoAbstract:Volatile Organics in water are analyzed by first removing them from the water matrix. For example in purge and trap, the Organics are sparged using an inert gas before analysis by GC or GC/MS. The objective of this research is to develop an equivalent of a purge and trap system based on membrane extraction. Instead of purging, the VOCs are separated from the aqueous phase via membrane permeation. The permeated Organics are pneumatically transported to a micro-sorbent trap referred to as the microtrap. The trapped Organics are then injected into a GC by rapid desorption of the microtrap.
Leroy Cronin - One of the best experts on this subject based on the ideXlab platform.
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embedding alkenes within an icosahedral inorganic fullerene nh4 42 mo132o372 l 30 h2o 72 for trapping Volatile Organics
Chemical Science, 2020Co-Authors: Robert Pow, Weimin Xuan, Deliang Long, Nicola L Bell, Leroy CroninAbstract:Eight alkene-functionalized molybdenum-based spherical Keplerate-type (inorganic fullerene) structures have been obtained via both direct and multistep synthetic approaches. Driven by the opportunity to design unique host–guest interactions within hydrophobic, π-electron rich confined environments, we have synthesised {(NH4)42[Mo132O372(L)30(H2O)72]}, where L = (1) acrylic acid, (2) crotonic acid, (3) methacrylic acid, (4) tiglic acid, (5) 3-butenoic acid, (6) 4-pentenoic acid, (7) 5-hexenoic acid, and (8) sorbic acid. The compounds, which are obtained in good yield (10–40%), contain 30 carboxylate-coordinated alkene ligands which create a central cavity with hydrophobic character. Extensive Nuclear Magnetic Resonance (NMR) spectroscopy studies contribute significantly to the complete characterisation of the structures obtained, including both 1D and 2D measurements. In addition, single-crystal X-ray crystallography and subsequently-generated electron density maps are employed to highlight the distribution in ligand tail positions. These alkene-containing structures are shown to effectively encapsulate small alkyl thiols (1-propanethiol (A), 2-propanethiol (B), 1-butanethiol (C), 2-butanethiol (D) and 2-methyl-1-propanethiol (E)) as guests within the central cavity in aqueous solution. The hydrophobically driven clustering of up to 6 equivalents of Volatile thiol guests within the central cavity of the Keplerate-type structure results in effective thermal protection, preventing evaporation at elevated temperatures (ΔT ≈ 25 K).
John J Manura - One of the best experts on this subject based on the ideXlab platform.
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analysis of Volatile Organics in cooking oils by thermal desorption gas chromatography mass spectrometry
Journal of Agricultural and Food Chemistry, 1995Co-Authors: Santford Vance Overton, John J ManuraAbstract:Volatile organic compounds (VOCs) were collected from samples of 14 commercial olive oils and cooking oils using a purge and trap technique (P&T) and analyzed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) to identify, compare, and quantify the Volatile Organics present. The P&T or dynamic headspace technique permits the analysis of a wider range of both Volatile and semiVolatile organic compounds and is more sensitive by a factor of at least 100 as compared to the static headspace technique. No solvent extraction is required, which eliminates the exposure of laboratory personnel to these compounds and also eliminates the disposal of these solvents. This analytical method can be utilized for the quality control of these oils during production, can be used to detect adulteration or contamination of the pure product, and may provide for a fingerprint chromatographic pattern for the comparison of oils or determination of origin.
Smruti Ragunath - One of the best experts on this subject based on the ideXlab platform.
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carbon nanotube immobilized composite hollow fiber membranes for extraction of Volatile Organics from air
Journal of Physical Chemistry C, 2015Co-Authors: Smruti Ragunath, Somenath MitraAbstract:This paper reports the development of novel carbon nanotube immobilized composite membranes (CNIMs) for the extraction of Volatile Organics from air. The nanotubes were immobilized onto the selective layer of a composite membrane where they served as sorption sites and provided additional pathways for enhanced solute transport. Depending upon the process conditions, the presence of carbon nanotubes led to the organic removal with flux as high as 37.7 × 10–5, 72.9 × 10–5, and 8.22 × 10–5 gm mol/m2 min and an increase in mass-transfer coefficient of about 92.2%, 22.7%, and 44.3% for toluene, dichloromethane, and ethanol, respectively. The CNIMs demonstrated several advantages, including enhanced recovery at low concentrations and low temperature.
Ornthida Saekhow - One of the best experts on this subject based on the ideXlab platform.
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carbon nanotube immobilized composite hollow fiber membranes for pervaporative removal of Volatile Organics from water
Journal of Physical Chemistry C, 2010Co-Authors: Ornthida Saekhow, Somenath MitraAbstract:This paper reports the development of novel carbon nanotube immobilized composite membranes (CNIM) for pervaporative removal of Organics from an aqueous matrix. The nanotubes were immobilized into the pores of a composite, where they served as sorption sites that provided additional pathways for enhanced solute transport, affecting both the partitioning and diffusion through the membrane. Depending upon the process conditions, the enhancement in organic removal and mass transfer rates were higher by 108 and 95%, respectively. The CNIM demonstrated several advantages including enhanced recovery at low concentrations, lower temperatures, and higher flow rates. Overall, these lead to more energy efficient processes.
