The Experts below are selected from a list of 1101 Experts worldwide ranked by ideXlab platform
Yun Zhao - One of the best experts on this subject based on the ideXlab platform.
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preparation of anion exchange membranes by an efficient chloromethylation method and homogeneous quaternization crosslinking strategy
Solid State Ionics, 2013Co-Authors: Zhigang Shao, Geng Zhang, Yun ZhaoAbstract:Abstract A novel chloromethylation method and homogeneous quaternization/crosslinking strategy for a series of polymers are demonstrated in this paper. The chloromethylation is accomplished by using 1, 4-bis (chloromethoxy) butane (BCMB) as the chloromethylating reagent and concentrated sulfuric acid as the solvent and catalyst. BCMB is a kind of high-efficient, non-carcinogenic and inexpensive chloromethylating reagent, and concentrated sulfuric acid replaces toxic Halogenated Hydrocarbon. Study results indicated that BCMB had higher reactivity than chloromethyl octyl ether under similar reaction conditions. The chloromethylated poly (phthalazinon ether sulfone ketone) (PPESK) was then crosslinked and quarternized by using N, N, N′, N′-tetramethyl-1, 6-hexanediamine (TMHDA) as the homogeneous quaternizing and crosslinking agent during the solvent evaporation. The ion exchange capacity (IEC) of the crosslinked membranes (C-QAPPESK/OH) was very close to the theoretical value, higher than that of the membranes quaternized by trimethylamine (TMA) aqueous solutions (QAPPESK/OH). In addition to higher IEC, C-QAPPESK/OH membranes possessed greater hydroxide conductivity and chemical stability than that of QAPPESK/OH membranes. The results suggest that this efficient chloromethylation together with the homogeneous quaternizing and crosslinking method is a time-saving strategy with potential application in the preparation of anion exchange membranes.
Geng Zhang - One of the best experts on this subject based on the ideXlab platform.
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preparation of anion exchange membranes by an efficient chloromethylation method and homogeneous quaternization crosslinking strategy
Solid State Ionics, 2013Co-Authors: Zhigang Shao, Geng Zhang, Yun ZhaoAbstract:Abstract A novel chloromethylation method and homogeneous quaternization/crosslinking strategy for a series of polymers are demonstrated in this paper. The chloromethylation is accomplished by using 1, 4-bis (chloromethoxy) butane (BCMB) as the chloromethylating reagent and concentrated sulfuric acid as the solvent and catalyst. BCMB is a kind of high-efficient, non-carcinogenic and inexpensive chloromethylating reagent, and concentrated sulfuric acid replaces toxic Halogenated Hydrocarbon. Study results indicated that BCMB had higher reactivity than chloromethyl octyl ether under similar reaction conditions. The chloromethylated poly (phthalazinon ether sulfone ketone) (PPESK) was then crosslinked and quarternized by using N, N, N′, N′-tetramethyl-1, 6-hexanediamine (TMHDA) as the homogeneous quaternizing and crosslinking agent during the solvent evaporation. The ion exchange capacity (IEC) of the crosslinked membranes (C-QAPPESK/OH) was very close to the theoretical value, higher than that of the membranes quaternized by trimethylamine (TMA) aqueous solutions (QAPPESK/OH). In addition to higher IEC, C-QAPPESK/OH membranes possessed greater hydroxide conductivity and chemical stability than that of QAPPESK/OH membranes. The results suggest that this efficient chloromethylation together with the homogeneous quaternizing and crosslinking method is a time-saving strategy with potential application in the preparation of anion exchange membranes.
Timothy P Rohrig - One of the best experts on this subject based on the ideXlab platform.
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1 1 difluoroethane forensic aspects for the toxicologist and pathologist
Journal of Analytical Toxicology, 2021Co-Authors: Nicholas B Tiscione, Timothy P RohrigAbstract:1,1-Difluoroethane (DFE) is a Halogenated Hydrocarbon that is commonly used as a propellant in air duster products. Herein the pharmacology of DFE was reviewed and questions relevant to medicolegal investigations were addressed. Particular emphasis was given to detection time in biological specimens and the range, onset and duration of effects. DFE may be abused as an inhalant and is rapidly absorbed through the lungs. Onset of central nervous system (CNS) depressant effects is within seconds and the duration may only last minutes. The effects may lead to impairment of human performance including confusion, lethargy, impaired judgement, loss of motor coordination, and loss of consciousness. Death may result even after the first use. With heavy use or in combination with other CNS depressants, extended periods of drowsiness or loss of consciousness may be observed with an increased risk of a fatal event. A majority of impaired driving investigations where DFE was identified included a collision demonstrating the significant impact its use may have on traffic safety. When DFE is identified alone, without other drugs that cause CNS impairment, the effects may not be observable minutes after the crash making identification of its use difficult. Although concentrations dissipate rapidly, DFE has been detected in blood specimens collected up to 3 hours after the driving incident. Two studies on passive exposure presented herein demonstrated that it is unlikely to detect DFE above concentrations of ~2.6 µg/mL in blood or urine due to even extreme unintential exposure. Alternative specimens such as brain, lung and tracheal air should be considered in some postmortem investigations. DFE has been identified in blood specimens from postmortem cases at concentrations from 0.14 to 460 µg/mL and in impaired driving cases from 0.16 to 140 µg/mL.
Hiroshi Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Halogenated Hydrocarbon solvent related cholangiocarcinoma risk biliary excretion of glutathione conjugates of 1 2 dichloropropane evidenced by untargeted metabolomics analysis
Scientific Reports, 2016Co-Authors: Yu Toyoda, Tappei Takada, Hiroshi SuzukiAbstract:Recently, the International Agency for Research on Cancer issued a warning about the carcinogenicity of 1,2-dichloropropane (1,2-DCP) to humans based on an epidemiological study suggesting a relationship between the incidence of cholangiocarcinoma and occupational exposure to Halogenated Hydrocarbon solvent comprised mostly of 1,2-DCP. Although this dihaloalkane has been used in various industrial fields, there has been no biological evidence explaining the cholangiocarcinoma latency, as well as little understanding of general cholangiocarcinoma risk. In the present study, we explored the biliary excretion of 1,2-DCP metabolites by an untargeted metabolomics approach and the related molecular mechanism with in vitro and in vivo experiments. We hypothesized that the biliary excretion of carcinogens derived from 1,2-DCP contribute to the increased cholangiocarcinoma risk. We found that 1,2-DCP was conjugated with glutathione in the liver, and that the glutathione-conjugated forms of 1,2-DCP, including a potential carcinogen that contains a chloride atom, were excreted into bile by the bile canalicular membrane transporter, ABCC2. These results may reflect a risk in the backfiring of biliary excretion as a connatural detoxification systems for xenobiotics. Our findings would contribute to uncover the latent mechanism by which the chronic exposure to 1,2-DCP increases cholangiocarcinoma risk and future understanding of cholangiocarcinoma biology.
Martin Reinhard - One of the best experts on this subject based on the ideXlab platform.
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tailoring catalysts for hydrodechlorinating chlorinated Hydrocarbon contaminants in groundwater
Applied Catalysis B-environmental, 2000Co-Authors: Christoph Schüth, Stephan Disser, Ferdi Schuth, Martin ReinhardAbstract:Abstract A palladium-on-zeolite catalyst has been optimized for treating groundwater contaminated with Halogenated Hydrocarbon compounds (HHCs) by hydrodechlorination with dissolved hydrogen. Aqueous sulfite was used as the model poison and the dechlorination of 1,2-dichlorobenzene (1,2-DCB) was used as the model reaction to study the relationship between zeolite hydrophobicity, pore size, and resistance against deactivation. The optimal Pd support is a hydrophobic zeolite Y with a pore size of 0.74 nm tailored to exclude reactive ions from internal sites, to minimize deactivation and inhibition, and to maximize the transformation rate of HHCs. Common Halogenated contaminants including chlorinated ethylenes and aromatics are removed within minutes. Catalyst efficiency under groundwater treatment conditions was demonstrated in a bench-scale column experiment.
