Journal articles on the topic 'Chloride'
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1
Lapina, E. A., S. A. Zverev, S. V. Andreev, and K. A. Sakharov. "Determination of chlorine-containing compounds in disinfectants using ion-exchange chromatography." Fine Chemical Technologies 18, no. 3 (August 2, 2023): 254–64. http://dx.doi.org/10.32362/2410-6593-2023-18-3-254-264.
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Objectives. To develop a method for the determination of hypochlorite, chloride, chlorite, chlorate, and perchlorate ions in solution; to determine the limits of detection and quantitation for ClO−, Cl−, ClO2−, ClO3−, and ClO4− ions; to evaluate the applicability of the developed method and its suitability for disinfectant analysis.Methods. Ionic chromatography using a conductometric detection system in isocratic elution mode.Results. The method developed for chromatographic determination of chlorine-containing ions can be used to quantify the content of hypochlorite, chloride, chlorite, chlorate, and perchlorate ions. In isocratic elution mode at 7.5 mM NaOH and a flow rate of 0.4 mL/min, the content of chlorine-containing ions can be determined with high sensitivity. The presented method does not require the use of expensive equipment for the ultrasensitive analysis of the studied compounds.Conclusions. A novel method for the simultaneous determination of hypochlorite, chloride, chlorite, chlorate, and perchlorate ions in case of their combined presence is proposed. The technique can be used to carry out routine control of the content of these disinfectant components during use, increasing their effectiveness at the same time as managing associated toxicological risks.
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Gambardella, Mario, Santad Kongpricha, James J. Pitts, and Albert W. Jache. "Disproportionation of chlorine in hydrogen fluoride and related media." Canadian Journal of Chemistry 67, no. 11 (November 1, 1989): 1828–31. http://dx.doi.org/10.1139/v89-283.
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Chlorine can be made to disproportionate to chlorine monofluoride and chloride, taking advantage of Le Chatelier's principle in several different ways. It will disproportionate to form insoluble silver chloride and chlorine monofluoride when silver fluoride is present. It will disproportionate in a melt of alkali metal fluorides to form alkali metal chlorides and chlorine monofluoride. The alkali metal chlorides will react with hydrogen fluoride to regenerate the metal fluorides and hydrogen chloride. Chlorine will also disproportionate in hydrogen fluoride containing antimony pentafluoride to yield antimony pentafluoride adducts of chlorine monofluoride and of hydrogen chloride. These adducts are readily decomposed to yield the disproportionation products and the original antimony pentafluoride. Keywords: hydrogen fluoride, disproportionation, chlorine, waterlike, solvent system.
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Svenson, Doug R., Hou-min Chang, Hasan Jameel, and John F. Kadla. "The role of non-phenolic lignin in chlorate-forming reactions during chlorine dioxide bleaching of softwood kraft pulp." Holzforschung 59, no. 2 (February 1, 2005): 110–15. http://dx.doi.org/10.1515/hf.2005.017.
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Abstract The affect of phenolic hydroxyl groups on the reaction efficiency during chlorine dioxide pre-bleaching of a softwood kraft pulp was investigated. The removal of phenolic hydroxyl groups via pulp methylation did not adversely affect the chlorine dioxide bleaching efficiency or the amount of chlorate formed during exposure to chlorine dioxide. Ion analysis of the reaction systems revealed that the formation of chloride and chlorite ions during the bleaching process were very similar between the kraft and methylated kraft pulps. These results indicate that the kinetic rates of lignin oxidation by chlorine dioxide and its reduction products, chlorite and hypochlorous acid, are much faster than the rate of inorganic reactions leading to chlorate formation.
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Paun, Iuliana, Florentina Laura Chiriac, Vasile Ion Iancu, Florinela Pirvu, Marcela Niculescu, and Nicoleta Vasilache. "Disinfection by-products in drinking water distribution system of Bucharest City." Romanian Journal of Ecology & Environmental Chemistry 3, no. 1 (June 25, 2021): 10–18. http://dx.doi.org/10.21698/rjeec.2021.102.
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Chlorine is widely used in Romania and all over the world as a disinfectant of drinking water. During the chlorination process, the natural organic matter and inorganic ions react with chlorine forming disinfection by-products (DBPs). The predominant organic disinfection by-products are trihalomethanes (THMs) while the main inorganic disinfection by-products are chlorate and chlorite ions. THMs were detected in all investigated drinking water samples from Bucharest distribution system with values from 27.8 µg/L up to 75.1 µg/L, which are below the maximum concentration value admitted by Romanian drinking water legislation of 100 µg/L. Chloroform constitutes the major component in total THMs concentration found in all tested drinking water. Chlorate and chlorite anions were not detected in any of the investigated drinking water samples. THMs concentration was correlated with total organic carbon (TOC), residual chlorine and chloride.
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Moore, Nathan, Shelir Ebrahimi, Yanping Zhu, Chengjin Wang, Ron Hofmann, and Susan Andrews. "A comparison of sodium sulfite, ammonium chloride, and ascorbic acid for quenching chlorine prior to disinfection byproduct analysis." Water Supply 21, no. 5 (March 2, 2021): 2313–23. http://dx.doi.org/10.2166/ws.2021.059.
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Abstract This study compared 3 commonly used quenching agents for dechlorinating samples prior to disinfection byproduct (DBP) analysis under typical drinking water sampling conditions for a representative suite of chlorination byproducts. Ascorbic acid and sodium sulfite quenched the residual free chlorine to below detection within 5 seconds. Ammonium chloride did not quench the chlorine to below detection with up to a 70% molar excess, which agrees with published ammonium chloride-chlorine chemistry. With respect to the DBPs, ascorbic acid worked well for the trihalomethanes and haloacetic acids, except for dibromoiodomethane, which exhibited 2.6–28% error when using ascorbic acid compared to non-quenched control samples. Sodium sulfite also worked well for the trihalomethanes (and performed similarly to ascorbic acid for dibromoiodomethane) and was the best performing quenching agent for MX and the inorganic DBPs, but contributed to the decay of several emerging DBPs, including several halonitromethanes and haloacetamides. Ammonium chloride led to considerable errors for many DBPs, including 27–31% errors in chloroform concentrations after 24 hours of storage. This work shows that ascorbic acid is suitable for many of the organic DBPs analyzed by gas chromatography-electron capture detection and that sodium sulfite may be used for simultaneous chlorite, chlorate, and bromate analysis.
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Kolmakov, Kirill A. "Reactions of aniline in acetic acid solutions containing cyanuric chloride and hydrogen chloride acceptors." Canadian Journal of Chemistry 85, no. 12 (December 1, 2007): 1070–74. http://dx.doi.org/10.1139/v07-129.
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Two reaction pathways in acetic acid solution containing cyanuric chloride, aniline, and some hydrogen chloride acceptors (triethylamine, sodium acetate, pyridine) were studied. Both aryl amination and acylation can be performed with high yields under proper reaction conditions. Contrary to the only known literature report on the reactions between carbonic acids and cyanuric chloride in the presence of a hydrogen chloride acceptor (triethylamine), it was established that acid chlorides are not formed. A scheme involving the replacement of chlorine atoms by acetate ion in the initial stage was proposed for the acylation of aniline promoted by cyanuric chloride.Key words: acetic acid, acylation, aniline, cyanuric chloride, aryl amination.
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Kang, Linda, Genevieve Lynch, Will Lynch, and Clifford Padgett. "Manganese(II) chloride complexes with pyridineN-oxide (PNO) derivatives and their solid-state structures." Acta Crystallographica Section E Crystallographic Communications 73, no. 10 (September 12, 2017): 1434–38. http://dx.doi.org/10.1107/s2056989017012038.
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Three manganese(II)N-oxide complexes have been synthesized from the reaction of manganese(II) chloride with either pyridineN-oxide (PNO), 2-methylpyridineN-oxide (2MePNO) or 3-methylpyridineN-oxide (3MePNO). The compounds were synthesized from methanolic solutions of MnCl2·4H2O and the respectiveN-oxide, and subsequently characterized structurally by single-crystal X-ray diffraction. The compounds arecatena-poly[[aquachloridomanganese(II)]-di-μ-chlorido-[aquachloridomanganese(II)]-bis(μ-pyridineN-oxide)], [MnCl2(C5H5NO)(H2O)]nor [MnCl2(PNO)(H2O)]n(I),catena-poly[[aquachloridomanganese(II)]-di-μ-chlorido-[aquachloridomanganese(II)]-bis(μ-2-methylpyridineN-oxide)], [MnCl2(C6H7NO)(H2O)]nor [MnCl2(2MePNO)(H2O)]n(II), and bis(μ-3-methylpyridineN-oxide)bis[diaquadichloridomanganese(II)], [Mn2Cl4(C6H7NO)2(H2O)4] or [MnCl2(3MePNO)(H2O)2]2(III). The MnIIatoms are found in pseudo-octahedral environments for each of the three complexes. CompoundIforms a coordination polymer with alternating pairs of bridgingN-oxide and chloride ligands. The coordination environment is defined by two PNO bridging O atoms, two chloride bridging atoms, a terminal chloride, and a terminal water. CompoundIIalso forms a coordination polymer with a similar metal cation; however, the coordination polymer is bridged between MnIIatoms by both a single chloride and 2MePNO. The distorted octahedrally coordinated metal cation is defined by two bridging 2MePNOtransto each other, two chlorides, alsotransto one another in the equatorial (polymeric) plane, and a terminal chloride and terminal water. Finally, complexIIIforms a dimer with two bridging 3MePNOs, two terminal chlorides and two terminal waters forming the six-coordinate metal environment. All three compounds exhibit hydrogen bonding between the coordinating water(s) and terminal chlorides.
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Strėlkutė, Asta, and Jolita Bradulienė. "CHLORIDE CONCENTRATION IN THE SOIL POLLUTED WITH BISHOPHIT USED IN WINTER AND ITS EFFECT ON HERBACEOUS PLANTS / CHLORIDŲ KONCENTRACIJA DIRVOŽEMYJE, UŽTERŠTAME ŽIEMOS METU NAUDOJAMU BIŠOFITU, IR POVEIKIS ŽOLINIAMS AUGALAMS." Mokslas – Lietuvos ateitis 6, no. 4 (October 24, 2014): 386–91. http://dx.doi.org/10.3846/mla.2014.53.
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For road maintenance in winter, various chemical reagents, considering their physical and chemical properties, are chosen taking into account economic indicators. After a long winter season, large amounts of chemical reagents are used. During the winter season, dusting chlorides, first of all, fall on the roadway and a part of those reach roadsides where directly pollute the soil of the buffer zone and affect vegetation during the growing season. Chloride content in soil reduces the absorption of nutrients, which hinders the development of plants. It also has an effect on the metabolism of soil organisms, and therefore the loss of soil fertility. Due to high chloride content, land becomes unsuitable for plant growth. Studies used different concentrations (9 ml, 12 ml and 46 ml) of bishophit. Chloride concentration in soil extract has been determined applying the volumetric method and employing silver nitrate titration. It has been determined that the amount of chloride in the soil contaminated with 9 ml makes 89.21 mg/kg, 12 ml – 94, 25 mg/kg and 164.32 mg/kg. Kelių priežiūrai žiemą naudojami įvairūs cheminiai reagentai, kurie parenkami atsižvelgiant į ekonominius rodiklius, svarbios yra jų fizinės bei cheminės savybės. Esant ilgam ir snieguotam žiemos sezonui, naudojami dideli kiekiai cheminių reagentų, kurie, atšilus orams, pasklinda aplinkoje ir daro neigiamą įtaką. Žiemą barstomi chloridai pirmiausia patenka ant važiuojamosios kelio dalies, dalis chloridų patenka ant kelkraščių, kur tiesiogiai teršia pakelėse esantį apsauginės zonos dirvožemį bei vegetacijos periodo augaliją. Chloridų kaupimasis dirvožemyje – viena svarbiausių ekosistemoms kylančių fiziologinių grėsmių. Chloridų kiekis dirvožemyje sumažina maistingųjų medžiagų pasisavinimą ir tai trukdo vystytis augalams. Taip pat tai turi poveikį dirvožemio organizmų medžiagų apykaitai, ir dėl to mažėja dirvožemio derlingumas. Dėl didelio chloridų kiekio žemė tampa netinkama augalams augti. Tyrimams naudojama skirtingų koncentracijų (9 ml, 12 ml, 46 ml) bišofitas. Chloridų koncentracija dirvožemio ekstrakte nustatoma tūriniu metodu, titruoti naudojant sidabro nitratą. Nustatyta, kad chloridų kiekis 9 ml užterštame dirvožemyje yra 8,388 mg/kg, 12 ml – 10,197 mg/kg, 28,19 mg/kg.
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Novoselova, Alena, Vladimir Shishkin, and Vladimir Khokhlov. "Redox Potentials of Samarium and Europium in Molten Lithium Chloride." Zeitschrift für Naturforschung A 56, no. 11 (November 1, 2001): 754–56. http://dx.doi.org/10.1515/zna-2001-1110.
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Abstract The samarium (III)/(II) and europium (III)/(II) redox potentials in molten lithium chloride were measured using the direct potentiometric method in the temperature range from 923 to 1094 K. Glassy carbon was used as the indifferent working electrode, and the standard chlorine electrode as a reference. The total concentration of rare-earth chlorides dissolved in molten lithium chloride did not exceed 4.5 mol%.
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Chandrasekara Pillai, K., Tae Ok Kwon, Bo Bae Park, and Il Shik Moon. "Using RuO2 anode for chlorine dioxide production in an un-divided electrochemical cell." Water Science and Technology 61, no. 8 (April 1, 2010): 2151–60. http://dx.doi.org/10.2166/wst.2010.131.
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Chlorine dioxide is a well known powerful disinfectant. Although there are several chemical and electrochemical methods developed for on-line chlorine dioxide generation, the details are mostly confined as patents. We studied in this work the electrochemical generation of dissolved chlorine dioxide from an un-buffered solution of sodium chlorite and sodium chloride mixture in an un-divided electrochemical cell set-up with RuO2-coated-Ti anode and Pt-coated-Ti cathode under constant current mode. Various process parameters including feed flow rate (10 to 150 ml/min), feed solution pH (2.3 to 9.4), concentration of sodium chloride (0 to 170 mM), concentration of sodium chlorite (0 to 7.7 mM), and the applied current (100 to 1,200 mA) were optimized. Experiments were conducted by performing single pass experiments, with no circulation. The current efficiency and the power consumption were calculated for the optimized conditions, and compared with IrO2 electrode of our previous investigation.
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Ferchichi, Olfa, Najoua Derbel, Thibaud Cours, and Alexander Alijah. "Dichlorine peroxide (ClOOCl), chloryl chloride (ClCl(O)O) and chlorine chlorite (ClOClO): very accurate ab initio structures and actinic degradation." Physical Chemistry Chemical Physics 22, no. 7 (2020): 4059–71. http://dx.doi.org/10.1039/c9cp06875a.
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The structural parameters of the three most stable isomers with formula Cl2O2, dichlorine peroxide, chloryl chloride and chlorine chlorite, were determined by high-level ab initio theory. The photodissociation pathways were investigated.
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Koishina, G. M., E. E. Zholdasbay, M. B. Kurmanseitov, E. B. Tazhiev, and A. A. Argyn. "Study on the behavior of zinc and associated metal-impurities in the process of chlorinating roasting of dross." Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu 318, no. 3 (September 12, 2021): 71–80. http://dx.doi.org/10.31643/2021/6445.30.
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In this work the issue of processing of dross with preliminary separation of the metal part from the oxide one is reviewed. Based on a comparative analysis of the results of known works it is shown that this approach can be quite effective if a technology is developed for the separate processing of the oxide part to obtain a commercial product. The authors of this work proposed carrying out chlorinating roasting under oxidizing conditions with various chlorine-containing reagents as one of the effective ways of processing the oxide part of the dross. Based on the thermodynamic analysis of the reactions of interaction between the components of the oxide part of the dross and calcium and ammonium chlorides, the principal possibility of obtaining pure zinc oxide, suitable for use as mineral additives in animal feed has been shown. As a result of thermodynamic calculations of the reactions of interaction of impurity metals with calcium chloride and ammonium chloride, the values of Gibbs free energy and reaction rate constants were determined in the temperature range 973 and 1373 K. It has been established that under the conditions of roasting the oxide part of the dross with both calcium chloride and ammonium chloride, a high degree of sublimation of impurity metals from the dross in the form of their chlorides into dust is achieved. It has been shown that roasting the oxide part of the dross using ammonium chloride is more efficient than with calcium chloride.
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Coates, John D., Urania Michaelidou, Royce A. Bruce, Susan M. O’Connor, Jill N. Crespi, and Laurie A. Achenbach. "Ubiquity and Diversity of Dissimilatory (Per)chlorate-Reducing Bacteria." Applied and Environmental Microbiology 65, no. 12 (December 1, 1999): 5234–41. http://dx.doi.org/10.1128/aem.65.12.5234-5241.1999.
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ABSTRACT Environmental contamination with compounds containing oxyanions of chlorine, such as perchlorate or chlorate [(per)chlorate] or chlorine dioxide, has been a constantly growing problem over the last 100 years. Although the fact that microbes reduce these compounds has been recognized for more than 50 years, only six organisms which can obtain energy for growth by this metabolic process have been described. As part of a study to investigate the diversity and ubiquity of microorganisms involved in the microbial reduction of (per)chlorate, we enumerated the (per)chlorate-reducing bacteria (ClRB) in very diverse environments, including pristine and hydrocarbon-contaminated soils, aquatic sediments, paper mill waste sludges, and farm animal waste lagoons. In all of the environments tested, the acetate-oxidizing ClRB represented a significant population, whose size ranged from 2.31 × 103 to 2.4 × 106 cells per g of sample. In addition, we isolated 13 ClRB from these environments. All of these organisms could grow anaerobically by coupling complete oxidation of acetate to reduction of (per)chlorate. Chloride was the sole end product of this reductive metabolism. All of the isolates could also use oxygen as a sole electron acceptor, and most, but not all, could use nitrate. The alternative electron donors included simple volatile fatty acids, such as propionate, butyrate, or valerate, as well as simple organic acids, such as lactate or pyruvate. Oxidized-minus-reduced difference spectra of washed whole-cell suspensions of the isolates had absorbance maxima close to 425, 525, and 550 nm, which are characteristic of type c cytochromes. In addition, washed cell suspensions of all of the ClRB isolates could dismutate chlorite, an intermediate in the reductive metabolism of (per)chlorate, into chloride and molecular oxygen. Chlorite dismutation was a result of the activity of a single enzyme which in pure form had a specific activity of approximately 1,928 μmol of chlorite per mg of protein per min. Analyses of the 16S ribosomal DNA sequences of the organisms indicated that they all belonged to the alpha, beta, or gamma subclass of the Proteobacteria. Several were closely related to members of previously described genera that are not recognized for the ability to reduce (per)chlorate, such as the generaPseudomonas and Azospirllum. However, many were not closely related to any previously described organism and represented new genera within the Proteobacteria. The results of this study significantly increase the limited number of microbial isolates that are known to be capable of dissimilatory (per)chlorate reduction and demonstrate the hitherto unrecognized phylogenetic diversity and ubiquity of the microorganisms that exhibit this type of metabolism.
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KUROSE, KEISUKE, TETSUJI OKUDA, SATOSHI NAKAI, TSUNG-YUEH TSAI, WATARU NISHIJIMA, and MITSUMASA OKADA. "HYDROPHILIZATION OF POLYVINYL CHLORIDE SURFACE BY OZONATION." Surface Review and Letters 15, no. 06 (December 2008): 711–15. http://dx.doi.org/10.1142/s0218625x08011986.
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The surface modification mechanism of polyvinyl chloride (PVC) by ozonation was investigated to study the selective hydrophilization of PVC surface among other plastics. Infrared analysis confirmed the increase of hydrophilic groups. XPS analysis revealed that the increase was due to the structural change in chlorine group in PVC to hydroxylic acid, ketone, and carboxylic groups by ozonation. This chemical reaction by ozone could occur only for polymers with chlorides in its structure and resulted in the selective hydrophilization of PVC among various polymers.
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Silina, I. S., Е. А. Katsman, Yu A. Treger, V. N. Rozanov, L. D. Iskhakova, R. P. Ermakov, V. V. Koltashev, and L. G. Bruk. "KINETICS OF OXIDATIVE CHLORINATION OF METHANE." Fine Chemical Technologies 12, no. 2 (April 28, 2017): 50–61. http://dx.doi.org/10.32362/2410-6593-2017-12-2-50-61.
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Heterogeneous oxidative chlorination of methane was investigated. The target product is methyl chloride. The investigated terms and conditions of oxychlorination of methane: process temperature 400°C, pressure 0.1-0.9 MPa, catalyst (% weight.): copper chloride (II) 1-8%; potassium chloride 2.5%; lanthanum chloride 1%; carrier - aluminosilicate. Powder X-ray diffractometry and electron microscopy showed that the active catalyst components (CuCl2, KCl, LaCl3) are unevenly distributed on the support surface (α-Al2O3·SiO2) and form agglomerates with a high salt content, including binary chlorides such as KCuCl3, K2CuCl3 or K2CuCl4, hydrates K2CuCl4·2H2O and CuCl2·2H2O and hydroxychlorides Cu3Cl4(OH)2 and Cu2Cl(OH)3. The kinetics of methane oxychlorination was studied in a gradientless reactor at 400°C and pressure 0.1 - 0.9 MPa by varying the partial pressures of the reactants. Analysis of the products was carried out by GC. An equation of the reaction rate including partial pressures of methane, hydrogen chloride and water to the 0.77, 0.01 and 0.64 power, respectively, but of zero order by oxygen and chlorine provides an adequate description of methyl chloride formation rate. Significant influence of water partial pressure is proved for the reaction under consideration.
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Moratalla, Ángela, Mayra K. S. Monteiro, Cristina Sáez, Elisama V. Dos Santos, and Manuel A. Rodrigo. "Full and Sustainable Electrochemical Production of Chlorine Dioxide." Catalysts 12, no. 3 (March 9, 2022): 315. http://dx.doi.org/10.3390/catal12030315.
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With the final purpose of manufacturing electrochemically-based devices that produce chloride dioxide efficiently, this paper focuses on the production of chlorates and hydrogen peroxide in two different electrochemical cells, in which operation conditions are selected to obtain high efficiencies, and in the subsequent combination of both electrochemically manufactured solutions to produce chlorine dioxide. Results demonstrate that suitable reagents can be produced by electrolyzing 20 g L−1 sodium chloride solutions at 50 mA cm−2 and 50 °C, and 3000 mg L−1 NaClO4 solutions at 5.0 mA cm−2 and 15 °C with current efficiencies of 30.9% and 48.0%, respectively. Different tests performed with these electrolyzed solutions, and also with commercial hydrogen peroxide and chlorate solutions, demonstrate that the ratio between both reagents plays a very important role in the efficiency in the production of chlorine dioxide. Results clearly showed that, surplus chlorate should be contained in the reagent media to prevent further reduction of chlorine dioxide by hydrogen peroxide and consequently, loses of efficiency in the process. During the reaction, a gas with a high oxidation capacity and consisting mainly in chloride dioxide is produced. The results contributed to the maximum conversion reached being 89.65% using electrolyzed solutions as precursors of ClO2, confirming that this technology can be promising to manufacture portable ClO2 devices.
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Geller, Jordan M., Ian S. Butler, Denis FR Gilson, Frederick G. Morin, Ivor Wharf, and F. Bélanger-Gariépy. "X-ray diffraction and solid-state 119Sn CP-MAS NMR studies of some triaryltin(IV) chlorides." Canadian Journal of Chemistry 81, no. 11 (November 1, 2003): 1187–95. http://dx.doi.org/10.1139/v03-115.
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The solid-state 119Sn cross-polarization (CP) magic angle spinning (MAS) NMR spectra of a series of triaryltin chlorides of the form Ar3SnCl have been acquired. The indirect spin-spin coupling constants (J(119Sn-35Cl)), quadrupolar-dipolar shifts (d(119Sn-35Cl)), and the 119Sn chemical shift tensors were extracted. For the spectrum of triphenyltin chloride (I) the validity of the first-order perturbation approximation was tested by comparing results of both the perturbation and cubic-equation approaches and a variable-temperature NMR study undertaken to investigate the influence of the previously reported molecular motion in the solid. The X-ray crystal structures of the tris(o-tolyl)tin chloride (II) and tris(p-tolyl)tin chloride (IV) complexes have been examined. They belong to the monoclinic and triclinic space groups P21/n and P[Formula: see text], respectively, which are different from the previously reported tris(m-tolyl)tin chloride (III) complex, which crystallizes in the space group R3 and has threefold molecular symmetry. The structures and NMR properties of the complexes with meta-substituents are quite different from those with ortho- or para-substituents having axially symmetric shift tensors with small spans and larger J values.Key words: aryltin chlorides, magic angle spinning NMR, tin-chlorine spin-spin coupling, 119Sn chemical shift tensor, crystal structure.
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ROZENTAL, N. K., and G. V. CHEKHNII. "CHLORIDE CORROSION OF REINFORCING STEEL." Bulletin of Science and Research Center of Construction 35, no. 4 (January 23, 2023): 174–85. http://dx.doi.org/10.37538/2224-9494-2022-4(35)-174-185.
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Introduction. Many years of experience in examining corrosion conditions show the dangerous adverse effects of chloride media on reinforced concrete structures.Although a large number of domestic and foreign publications have been devoted to the aggressive action of chloride salts on reinforcing steel, protection against chloride corrosion remains a relevant issue.Aim. In this work, the state of this problem, along with the methods for determining the chloride content in concrete, was assessed in order to propose the means to increase its protective action in aggressive chloride media.Materials and methods. This article discusses the following issues:– maximum permissible chloride content in concrete;– binding of chlorides by components in the matrix, the role of the mineral composition of cement;– critical evaluation of methods for determining the chloride content in concrete;– reduction of the diffusion permeability of chlorides in concrete as a method of corrosion protection.Results. The article presents the data on moisture tests of reinforced concrete prepared using Portland cement having various contents of alite, belite, and tricalcium aluminate, as well as CaCl2 additive.Indicated were the challenges of identifying aggressive free chlorides in the matrix. The need to develop a standard method for determining free chlorides in concrete was discussed. Until such a standard is developed, the chloride aggressiveness to steel in concrete can be assessed by the electrochemical method. It was shown that concretes of extremely low diffusion permeability obtained using advanced complex additives that reduce the water demand of concrete mixtures and change the charge of the matrix surface can be used as a protection measure against chloride corrosion.Presented are the results of determining the potentials of steel in concrete by electrochemical method, chlorides in concrete by colorimetric method, and diffusion permeability of chlorides in concrete.Conclusion. The corrosion activity of chlorides against reinforcing steel depends on a large number of factors, including the total chloride content and the amount of free, physically, and chemically bound chlorides.Since chloride binding depends on a large number of technological factors, it is recommended to perform electrochemical tests of reinforcing steel in concrete as per GOST 31383 to assess the hazard level of chlorides introduced into concrete with initial materials; a decision on the protective measures for reinforcing steel in chloride environments should be made on the basis of the obtained results.
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Kim, Gwangmok, and Sangwon Park. "Chloride Removal of Calcium Aluminate-Layered Double Hydroxide Phases: A Review." International Journal of Environmental Research and Public Health 18, no. 6 (March 10, 2021): 2797. http://dx.doi.org/10.3390/ijerph18062797.
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Chlorine is a critical element with respect to the use of fossil fuel, recycling of industrial wastes, and water purification. Chlorine could form toxic chemical compounds, corrode pipe systems and boilers, and contaminate surface and ground waters. Calcium aluminate-layered double hydroxides are one of the most promising materials to remove chlorides due to the chemisorption mechanism, since the phases have positively charged interlayers. Many studies on the synthesis and the characterization of calcium aluminate-layered double hydroxides have been extensively conducted, whereas few studies have been conducted on the chloride removal characteristics of the phases. The state-of-the-art studies on the synthesis methods and the structural characteristics of CaAl-LDH phases, the underlying mechanism on the removal of chlorides, and the potential removal rate and the capacity in the present study were thoroughly reviewed.
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Roy, Chandra D. "Regioselective Conversion of Unsymmetrical Terminal Epoxides into Vicinal Chlorohydrins Using Dimethoxyboron Chloride." Australian Journal of Chemistry 59, no. 11 (2006): 834. http://dx.doi.org/10.1071/ch06315.
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A highly regioselective synthesis of chlorohydrins by chlorinative cleavage of unsymmetrical epoxides utilizing dimethoxyboron chloride is described. Except for styrene oxide, all the terminal epoxides were regioselectively cleaved following a predominantly SN2-type reaction pathway favouring the formation of primary chlorides. In the case of styrene oxide, a benzylic epoxide, (MeO)2BCl transfers the chlorine at the benzylic position, by following an apparent SN1-type mechanism.
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Zacharda, Vojtěch, and Jiří Němeček. "EXPERIMENTAL STUDIES OF ACCELERATED CHLORIDE TRANSPORT IN CONCRETE." Acta Polytechnica CTU Proceedings 22 (July 25, 2019): 139–44. http://dx.doi.org/10.14311/app.2019.22.0139.
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This contribution deals with the efficiency of electromigration of chlorides used as a repair method for reinforced concrete structures. Experimental studies of accelerated chloride transport tests were performed on samples of concrete without chlorides and with admixed sodium chloride during concreting. Two concrete types from Portland cement characterized with normal and low compressive strengths were studied. The electromigration was applied to penetrate chlorides into the chloride-free sample and for extraction of chlorides from the sample. The effectiveness of the chloride extraction process for rehabilitation of reinforced concrete in terms of lowering the chloride concentration in different concrete types and surface concentration was observed. Electrical extraction was found to be effective for lowering of initial chloride concentration by 15-20% after 24 hours. The decrease in surface concentrations was found in the range of 40-50%. The extraction process was found to be feasible and effective for both concrete types.
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Ghani, Hassan, Emad Yousif, Dina S. Ahmed, Benson M. Kariuki, and Gamal A. El-Hiti. "Tin Complexes of 4-(Benzylideneamino)benzenesulfonamide: Synthesis, Structure Elucidation and Their Efficiency as PVC Photostabilizers." Polymers 13, no. 15 (July 23, 2021): 2434. http://dx.doi.org/10.3390/polym13152434.
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Poly(vinyl chloride) (PVC) suffers from photo-oxidation and photodegradation when exposed to harsh conditions. Application of PVC thus relies on the development of ever more efficient photostabilizers. The current research reports the synthesis of new complexes of tin and their assessment as poly(vinyl chloride) photostabilizers. The three new complexes were obtained in high yields from reaction of 4-(benzylideneamino)benzenesulfonamide and tin chlorides. Their structures were elucidated using different tools. The complexes were mixed with poly(vinyl chloride) at a very low concentration and thin films were made from the blends. The effectiveness of the tin complexes as photostabilizers has been established using a variety of methods. The new tin complexes led to a decrease in weight loss, formation of small residues, molecular weight depression, and surface alteration of poly(vinyl chloride) after irradiation. The additives act by absorption of ultraviolet light, removal the active chlorine produced through a dehydrochlorination process, decomposition of peroxides, and coordination with the polymeric chains. The triphenyltin complex showed the greatest stabilizing effect against PVC photodegradation as a result of its high aromaticity.
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Mitrofanova, S. A., and I. V. Murav’eva. "Determination of chlorine in dusty waste in ferronickel production: Analysis and estimation of uncertainty." Izvestiya. Ferrous Metallurgy 65, no. 9 (October 2, 2022): 629–36. http://dx.doi.org/10.17073/0368-0797-2022-9-629-636.
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A key stage in ferronickel production is sulfate-chlorination roasting, after which and at subsequent stages (up to the final product) exhaust gases are formed in the system accompanied by dust and metal chloride vapors outlet in roasting furnace. Enrichment of wastes during their removal with condensed chlorides indicates a decrease in the efficiency of sulfate-chlorination roasting. Therefore, the control of mineral chlorine in filter sediments is important both from the standpoint of environmental monitoring and evaluation of the technological process efficiency. In order to determine mineral chlorine in dusty waste during the ferronickel production, a quantitative chemical analysis procedure based on the ionometric method was developed in the testing laboratory of the South Ural Nickel Plant. This paper proposes a procedure for estimating the results uncertainty in determining chlorine in the sample. It consists of the following steps: compiling a mathematical model to determine the chloride-ion mass fraction, estimating the input quantities in the mathematical model and their uncertainties, estimating the output quantities in the mathematical model and their uncertainties, budgeting for uncertainty, determining the expanded uncertainty and presenting the results. The paper considers the results of calculating the total expanded uncertainty in determining the chloride-ion mass fraction – U(XCl – ) = ±9.4 % (kp = 2, P = 95 %) – for the samples with chlorine mass fraction from 0.4 to 0.8 %. Application of the proposed methodology in calculating uncertainty ensures reliable results in determining chlorine in dusty wastes of ferronickel production, which has a positive effect on the technological process and environmental monitoring efficiency.
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Diyamandoglu, V. "Nitrate and chloride formation in chloramination." Water Science and Technology 30, no. 9 (November 1, 1994): 101–10. http://dx.doi.org/10.2166/wst.1994.0453.
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The formation of nitrate and chloride as end-products of chloramination (combined chlorination) was investigated at pH ranging between 6.9 and 9.6 at 25°C. The experimental results comprised concentration-time profiles of combined chlorine residuals along with nitrate and chloride. Nitrite, if present, was always below the detectibility limit of the analytical method used (25 ppb). Mass balances on chlorine species depicted that chloride formed during the slow decay of combined chlorine residuals does not account for all the chlorine lost. This substantiates the formation of other reaction end-products which are yet to be identified. A kinetic model for chloramination is proposed based on the kinetic data obtained in this study.
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Suryavanshi, A. K., R. N. Swamy, and S. McHugh. "Chloride penetration into reinforced concrete slabs." Canadian Journal of Civil Engineering 25, no. 1 (January 1, 1998): 87–95. http://dx.doi.org/10.1139/l97-046.
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The overall aim of this paper is to establish the process and amount of chlorides penetrating reinforced concrete elements when exposed to a salt-laden environment. For this purpose, a number of slabs were subjected to 70 cycles of wetting-drying regime with a 4% sodium chloride solution over a period of 2-3 years. To examine the direction of transportation of the chlorides, some of the slabs were partially coated with a surface coating system known to be highly resistant to chloride penetration. The amount and depth of penetration of chlorides in the coated and uncoated parts of the slab were then determined. The results show conclusively that, in large exposed areas of concrete, chlorides diffuse both in the direction of depth and in a direction lateral to the depth of the element. The amount of chlorides and the distance of their lateral diffusion depend on the water-to-cement (w/c) ratio of the concrete and the duration of exposure. Concrete mixes with a high w/c ratio (0.75) are highly conducive to this lateral diffusion of chlorides. Although concrete mixes of lower w/c ratios (0.45 and 0.60) are less conducive to lateral diffusion of chlorides, in practice, all concretes should be considered to be prone to chloride diffusion in both the direction of gravity and the lateral direction because of the effects of cracking. In unprotected concrete, reducing the w/c ratio from 0.60 to 0.45 is far more effective in decreasing chloride penetration than that achieved by reducing the w/c ratio from 0.75 to 0.60. The acrylic-based surface coating system is totally resistant to chloride penetration.Key words: chloride diffusion, concrete slabs, durability, water-to-cement ratio, surface coating, lateral diffusion.
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Kim, Min Jae, Ki Beom Kim, and Ki Yong Ann. "The Influence of C3A Content in Cement on the Chloride Transport." Advances in Materials Science and Engineering 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/5962821.
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The present study concerns the influence of C3A in cement on chloride transport in reinforced concrete. Three modified cement was manufactured in the variation of the C3A content, ranging from 6.0 and 10.5 up to 16.9%. The setting time of fresh concrete was measured immediately after mixing, together with the temperature at the time of initial set. For properties of hardened concrete in the variation in the C3A, a development of the compressive strength and chloride permeation were measured using mortar specimens. Simultaneously, chloride binding capacity was measured by the water extraction method. To ensure the influence of pore structure on chloride transport, the pore structure was examined by the mercury intrusion porosimetry. As a result, it was found that an increase in the C3A content resulted in an increase in chloride binding capacity. However, it seemed that increased binding of chlorides is related to the higher ingress of chlorides, despite denser pore structure. It may be attributed to the higher surface chloride, which could increase the gradient of chloride concentration from the surface, thereby leading to the higher level of chloride profiles. Substantially, the benefit of high C3A in resisting corrosion, arising from removal of free chlorides in the pore solution, would be offset by increased chloride ingress at a given duration, when it comes to the corrosion-free service life.
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Rodriguez, Rocio Aranda, Boniface Koudjonou, Brian Jay, Guy L. LeBel, and Frank M. Benoit. "Disinfection By-Products (DBPs) in Drinking Water from Eight Systems Using Chlorine Dioxide." Water Quality Research Journal 43, no. 1 (February 1, 2008): 11–22. http://dx.doi.org/10.2166/wqrj.2008.003.
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Abstract A study was initiated to determine the presence of organic disinfection by-products (DBPs) in drinking water treated with chlorine dioxide (ClO2). One potential advantage for the use of ClO2 as a disinfectant is the reduced formation of organic DBPs. Generally, water treated with ClO2 produces chlorite and chlorate ions, but there is limited information regarding the presence of halogenated organic DBPs. Eight systems that use chlorine dioxide as part of the water disinfection process were investigated. All systems in this study applied chlorine as a primary or secondary disinfectant in addition to ClO2. To evaluate seasonal and spatial variations, water samples were collected during cold water (February to March 2003) and warm water (July to August 2003) months at five sites for each system: raw water (R, before treatment), treated water (T, after treatment but before distribution), and three points along the same distribution line (D1, D2, D3). Sampling and analysis were conducted according to established protocols. A suite of 27 organic DBPs including haloacetic acids (HAA), trihalomethanes (THM), haloacetonitriles (HAN), haloketones, haloacetaldehydes (HA), chloropicrin, and cyanogen chloride were examined. In addition, the concentration of oxyhalides (chlorite and chlorate ions) and auxiliary parameters were also determined. Chlorite was found in treated (T) and distributed (Dx) waters. The chlorite ion levels decreased along the distribution system (T > D1 > D2 > D3). At T sites, the levels ranged from 10 to 870 µg/L (winter), and from 300 to 1,600 µg/L (summer). Chlorite was not found in treated or distributed water in the one system that used ozone. Chlorate ion levels ranged from 20 to 310 µg/L (winter), and 80 to 318 µg/L (summer). Chlorate levels remained relatively constant throughout the distribution system. THM and eight HAA (HAA8) accounted for approximately 85% of the total DBPs (wt/wt) analyzed, followed by total HA (up to 7%) and HAN (3%). THM in distributed water were found at concentrations between 1.8 and 30.6 µg/L (winter), and 3.3 and 93.6 µg/L (summer). For HAA8, the levels ranged from 13 to 52 µg/L (winter), and 16 to 111 µg/L (summer). Chloral hydrate ranged from 0.2 to 5.2 µg/L (winter), and 0.4 to 12.2 µg/L (summer). The temporal and spatial variations observed in previous studies were confirmed in the current study as well.
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McLennan, Duncan J., Allan R. Stein, and Brian Dobson. "Chlorine isotope effects in the solvolysis of substituted 1-phenylethyl chlorides." Canadian Journal of Chemistry 64, no. 6 (June 1, 1986): 1201–5. http://dx.doi.org/10.1139/v86-199.
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Kinetic chlorine isotope effects attending the solvolysis of several ring-substituted 1-phenylethyl chlorides in alcohol–water solvent mixtures are reported. The k35/k37 values are insensitive to the identity of ring substituents and to solvent composition. Results are interpreted in terms of an SN1 heterolytic process incorporating a significant amount of internal return. Theoretical calculations suggest that the incipient chloride ion in the transition state may be strongly hydrogen-bonded.
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Malheiro, Raphaele, Aires Camões, Gibson Meira, Maria Teresa Amorim, and João Castro-Gomes. "Effect of coupled deterioration by chloride and carbonation on chloride ions transport in concrete." RILEM Technical Letters 5 (September 25, 2020): 56–62. http://dx.doi.org/10.21809/rilemtechlett.2020.126.
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Carbonation is one of the factors that can influence the chlorides transport. Despite the combined action of chlorides and carbonation being a reality, there is no consensus on the effect of this coupled deterioration on chloride transport. Accelerated tests were used to simulate this environment. Concrete specimens were cast using 0.60 water/cement ratio and CEM I 42.5R. After curing, half of specimens was submitted to accelerated carbonation test (20ºC, 55% RH and 4% CO2) during 1 and 7 months. The other half was protected with plastic film during the same period. Then, the specimens were submitted to the accelerated chlorides attack using: migration test and immersion test. Finished the immersion test, powder samples were extracted from surface to bulk and analysed to obtain free and total chloride profiles and pH profile. According to migration test results, the carbonation increases chloride transport regardless the test period. According to the immersion test results, there is a decrease in chloride ions transport when the specimens are carbonated for 1 month and a noticeable increase when carbonation period increases to 7 months. The redistribution of pores in carbonated concrete and the difficulty of chlorides binding in carbonated concrete are related to these results.
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Janků, Josef, Jiří Burkhard, and Luděk Vodička. "Reaction of adamantanone, diamantanone, and their derivatives with thionyl chloride." Collection of Czechoslovak Chemical Communications 52, no. 8 (1987): 2028–34. http://dx.doi.org/10.1135/cccc19872028.
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In reaction of adamantanone, diamantanone, and their chloro or oxo derivatives with thionyl chloride the oxo group is replaced with two chlorine atoms under formation of geminal dichloro derivatives. The presence of a chlorine atom or an oxo group in both ketones reduces the reaction rate. The reaction rate decreases with decreasing distance between the substituent and the carbonyl group. Ketones with chlorine atom in α- or β-axial position do not react with thionyl chloride. The reaction is accelerated by hydrogen chloride whereas in the presence of pyridine no reaction was observed.
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Xu, Cuisheng, Ningke Hao, Lei Zhan, Shiwei Wang, Shuangquan Yao, Shuangxi Nie, and Shuangfei Wang. "High Purity Chlorine Dioxide Generation Based on the Mixed Reductant: From the Laboratory to Industry." Journal of Biobased Materials and Bioenergy 13, no. 4 (August 1, 2019): 517–22. http://dx.doi.org/10.1166/jbmb.2019.1885.
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Methanol was used as reducing agent in the chlorine dioxide generation technology, and sodium chlorate was reduced to form chlorine dioxide under acidic conditions. The side reaction during the preparation process would produce chlorine, which results in a high content of chlorine in the product and leads to an increase in the amount of AOX formation during pulp bleaching. In this work, the chlorine dioxide generation technology based on the mixed reductant was developed. On the basis system based on the methanol method, a high-purity chlorine dioxide for pulp bleaching was successfully produced using a vertical generator by adding a mixed reducing agent that contain hydrogen peroxide and sodium chloride. This invention can not only solve the problems of low conversion rate of sodium chlorate and high content of chlorine in the traditional methanol reduction method, but also reduces the production cost. The chlorine content in the chlorine dioxide solution is reduced to less than 0.2 g/L.
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Kitaeva, D. Kh, A. G. Buyanovskaya, O. A. Levinskaya, and S. L. Dzvonkovski. "Determination of low chlorine content in organic compounds and polymers using an «Expert-006» coulometer." Industrial laboratory. Diagnostics of materials 84, no. 7 (August 8, 2018): 16–20. http://dx.doi.org/10.26896/1028-6861-2018-84-7-16-20.
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A method of visual mercurimetric titration of chloride ions is widely used in elemental microanalysis for determination of chlorine content in organic substances after their combustion in an oxygen-filled flask. However, when chlorine content is less than 0.5%, the mercurimetric method fails to provide essential accuracy, and a more sensitive method of chlorine coulometric titration by electrogenerated silver ions appeared favorable. We consider a possibility of determining the microgram content of chloride-ions in solutions using a digital coulometric analyzer («Expert-006» produced by «Econics-Expert» (Moscow)) supplemented with an electrolytic cell with silver electrodes. The coulometer was tested in different operation modes to select the optimal electrochemical parameters of ion chloride titration and develop a technique for coulometric determination of chloride ions which in combination with the preliminary burning of the analyzed substances in an oxygen-filled flask provides determination of the residual chlorine in organic matrices at a level of 0.1 – 0.5%. The proposed technique was used to determine the residual chlorine in a number of polymers. The relative error did not exceed 5% at chlorine concentrations of 0.16 – 0.28%.
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Faming, Liu, Ye Shujin, and Ma Jie. "Mechanical Properties of Concrete After Chlorine Salt Extraction in Freeze-Thaw Environment." Open Civil Engineering Journal 8, no. 1 (December 31, 2014): 360–67. http://dx.doi.org/10.2174/1874149501408010360.
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Steel corrosion caused by chlorine salt erosion, degrade performance of reinforced concrete structures. Lead to can't use or need to reinforce the maintenance structure, produce the huge economic losses. The research of this subject is also a worldwide difficult problem. The freeze-thaw damage of concrete is a complex process of physical change. The chlorine salt erosion is often accompanied by freezing and thawing process. Make concrete structure is in a very bad environment. According to different sources of chloride ion and adopt general international electrochemical chloride extraction testing method of concrete specimens after different freezing and thawing times, the effect of chloride extraction, compressive strength, permeability resistance are studied. It is concluded that the chloride extraction, the strength and durability of the concrete member after freezing and thawing has had certain improvement, especially the durability has a lot to improve. In addition, put forward to increase thickness of concrete cover, preferable high-performance concrete resistance to chloride, strictly control the content of chlorine ion in concrete raw materials, adding reinforcement rust and corrosion inhibitor, adopting concrete corrosion layer, special steel, cathodic protection and so on measures to prevent the chlorine salt erosion. For electrochemical chloride extraction technique in reinforced concrete hydraulic structure, the application of civil engineering in the marine environment which it is provided the theoretical foundation and promotion.
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In, Kwang Jin, Y. R. Jiang, Sang Hwa Jung, Myung Kue Lee, Sung Won Yoo, and Byung Hwan Oh. "Durability of Concrete under Combined Exposure Conditions of Chlorides and Sulfates." Key Engineering Materials 711 (September 2016): 319–26. http://dx.doi.org/10.4028/www.scientific.net/kem.711.319.
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Concrete structures are generally subjected to serious deterioration under harsh environment, even though the concrete materials exhibit inherently higher durability than any other construction materials. The service life of concrete structures is directly affected by the durability performance under various conditions. In this regard, many studies have been conducted on the deterioration of concrete structures under various environmental conditions. However, previous studies were confined mostly to the deterioration of concrete structures under single deteriorating factor such as chloride ingress only or sulfate attack only, although real environment is actually a combination of such factors. The purpose of the present study is, therefore, to explore the effects of combined deterioration due to chlorides and sulfates in concrete structures. To this end, comprehensive experimental program has been set up to observe the chloride penetration behavior under combined deterioration conditions of chlorides and sulfates. The test results indicate that the chloride penetration is more pronounced for the case of combined attacks of chloride and sulfates than the case of single chloride attack. The surface chloride content is found to increase with time and this phenomenon is also more pronounced under the combined exposure of chlorides and sulfates. The present study may allow more realistic assessment of durability for such concrete structures which are subjected to combined attacks of chlorides and sulfates.
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Horikawa, Sanae, Yoshifumi Takai, Hiroichi Ukei, Naoto Azuma, and Akifumi Ueno. "Chlorine gas recovery from polyvinyl chloride." Journal of Analytical and Applied Pyrolysis 51, no. 1-2 (July 1999): 167–79. http://dx.doi.org/10.1016/s0165-2370(99)00015-7.
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Öberg, G. "Chloride and Organic Chlorine in Soil." Acta hydrochimica et hydrobiologica 26, no. 3 (May 1998): 137–44. http://dx.doi.org/10.1002/(sici)1521-401x(199805)26:3<137::aid-aheh137>3.0.co;2-1.
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KAUR, SIMRAN, DAVID J. SMITH, and MARK T. MORGAN. "Chloroxyanion Residue Quantification in Cantaloupes Treated with Chlorine Dioxide Gas." Journal of Food Protection 78, no. 9 (September 1, 2015): 1708–18. http://dx.doi.org/10.4315/0362-028x.jfp-14-576.
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Previous studies show that treatment of cantaloupes with chlorine dioxide (ClO2) gas at 5 mg/liter for 10 min results in a significant reduction (P < 0.05) in initial microflora, an increase in shelf life without any alteration in color, and a 4.6- and 4.3-log reduction of Escherichia coli O157:H7 and Listeria monocytogenes, respectively. However, this treatment could result in the presence of chloroxyanion residues, such as chloride (Cl−), chlorite (ClO2−), chlorate (ClO3−), and perchlorate (ClO4−), which, apart from chloride, are a toxicity concern. Radiolabeled chlorine dioxide (36ClO2) gas was used to describe the identity and distribution of chloroxyanion residues in or on cantaloupe subsequent to fumigation with ClO2 gas at a mean concentration of 5.1 ± 0.7 mg/liter for 10 min. Each treated cantaloupe was separated into rind, flesh, and mixed (rind and flesh) sections, which were blended and centrifuged to give the corresponding sera fractions. Radioactivity detected, ratio of radioactivity to mass of chlorite in initial ClO2 gas generation reaction, and distribution of chloroxyanions in serum samples were used to calculate residue concentrations in flesh, rind, and mixed samples. Anions detected on the cantaloupe were Cl− (~90%) and ClO3− (~10%), located primarily in the rind (19.3 ± 8.0 μg of Cl−/g of rind and 4.8 ± 2.3 μg of ClO3−/g of rind, n = 6). Cantaloupe flesh (~200 g) directly exposed to 36ClO2 gas treatment showed the presence of only Cl− residues (8.1 ± 1.0 μg of Cl−/g of flesh, n = 3). Results indicate chloroxyanion residues Cl− and ClO3− are only present on the rind of whole cantaloupes treated with ClO2 gas. However during cutting, residues may be transferred to the fruit flesh. Because Cl− is not toxic, only ClO3− would be a toxicity concern, but the levels transferred from rind to flesh are very low. In the case of fruit flesh directly exposed to ClO2 gas, only nontoxic Cl− was detected. This indicates that ClO2 gas that comes into contact with edible flesh would not pose a health concern.
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Yuan, Yezhen, Kaimin Niu, Bo Tian, Lijuan Kong, and Lihui Li. "Effect of Metakaolin on the Diffusion Properties of Chloride Ions in Cement Mortar under the Coupling Effect of Multiple Factors in Marine Environment." Advances in Civil Engineering 2023 (May 25, 2023): 1–15. http://dx.doi.org/10.1155/2023/6961234.
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To address the problem of chloride ion transport in cement concrete in marine environment, this study investigates the effect of metakaolin dosage on the chloride ion diffusion resistance of mortar and its mechanism by testing the chloride ion binding capacity and microstructure of mortar under the coupling effect of chlorine salt-sulfate-carbonation multiple factors. The results show that the coupling of sulfate or carbonation reduces chloride ion transport to some extent compared with single chlorine salt attack, while the three-factor coupled environment promotes free chloride ion diffusion. This is because the products of calcium alumina, gypsum, and calcium carbonate grow together and compete with each other to form more large capillaries; thus, accelerating the diffusion of chloride ions in cement mortar. Metakaolin, due to its higher pozzolanic activity, increases the monocarbon aluminate content in the erosion products, promotes F-salt generation, and increases the Al/Si ratio, which strengthens the binding ability of C-S-H gel to chloride ions, so the free chloride ion concentration inside the specimens doped with metakaolin is lower. In particular, the three-factor coupled environment has less 0.05–10 μm capillary pore content and higher F-salt stability in the specimens, which has the strongest effect on chloride ion curing, and the free chloride ion concentration integral in M-SCCl is reduced by nearly 30% compared with MF-SCCl and F-SCCl.
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Tokai, Masaya, Yoshimitsu Sakaguchi, and Yasuo Kato. "Preparation and properties of poly(etber ketone)s derived from 2,6-naphthalenedicarboxylic acid chloride." High Performance Polymers 7, no. 3 (June 1995): 267–74. http://dx.doi.org/10.1088/0954-0083/7/3/003.
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Poly(ether ketone)s derived from diphenyl ether and mixed diacid chlorides containing 2,6-naphthalenedicarboxyliUc acid chloride (NDC) with terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC) were prepared by Friedel-Crafts acylation in 1,2-dichloroethane with aluminium trichloride as a catalyst. Their thermal properties were widely controlled by changing the composition of diacid chlorides; the glass transision temperature was in the range of 156-203 °C and the melting temperature was 235-390 °C. The order of the structural effect of acid chlorides in increasing the glass transition temperature was NDC > TPC> IPC, and that in decreasing the gas permeability was IPC — NDC > TPC.
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Gao, Kangning, Jie Lu, Xi Wang, Dengxin Li, and Shihong Xu. "Effect of cations on the removal rate of chloride ions and mechanism analysis in high-salt wastewater." Water Science and Technology 83, no. 9 (March 17, 2021): 2232–41. http://dx.doi.org/10.2166/wst.2021.098.
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Abstract Precipitation dechlorination has the advantage of being a simple process with a low cost. However, there are few reports on the effect of cations on dechlorination. In this study, we investigated the effect of cations in high-salt wastewater on the removal of chlorine ions by cuprous chloride precipitation and analysed the corresponding mechanism. A series of investigations revealed that Fe3+ could oxidise sulphite, thereby reducing the removal rate of chlorine ions. The reaction between magnesium and sulphite results in precipitation, which has a slightly adverse effect on the removal of chloride ions. Hexavalent chromium oxidises the chloride ion, resulting in the formation of chlorine gas, which improves the removal rate. Ferrous and manganese, however, do not have a notable effect on chlorine removal.
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Limpo, J. L., A. Luis, and M. C. Cristina. "Hydrolysis of cupric chloride in aqueous ammoniacal ammonium chloride solutions." Revista de Metalurgia 31, no. 3 (June 30, 1995): 150–55. http://dx.doi.org/10.3989/revmetalm.1995.v31.i3.961.
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Gray, Lilian, and Peter G. Jones. "Secondary Bonding Interactions in Some Dichloroanilinium Chlorides." Zeitschrift für Naturforschung B 57, no. 1 (January 1, 2002): 73–82. http://dx.doi.org/10.1515/znb-2002-0109.
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Of the six structures presented here, five involve clearly defined hydrophilic layers built up from classical hydrogen bonding systems. Of three solvent-free structures, 2,4- and 3,5-dichloroanilinium chlorides both form ribbon structures involving annelated R24 (8) rings with NH2 donors (two hydrogen atoms from the positively charged NH3 groups) and chloride acceptors. The ribbons are linked by weaker interactions to form layers. 2,5-Dichloroanilinium chloride forms a layer structure directly, with rings R36 (12) exactly analogous to those previously observed in 2-chloroanilinium chloride. 2,6-Dichloroanilinium chloride methanol solvate forms a different type of ribbon structure, with alternating R24 (8) and R46 12) rings; the latter involve two chlorides, two NH2 groups and two methanols. These ribbons too are linked to form layers. 2,3-Dichloroanilinium chloride hydrate forms layers with two types of ring R35 (10); one involves two NH2, two chlorides and the OH part of a water, whereas in the other, an NH2 is replaced by OH2. In all these structures the aromatic groups project approximately perpendicular to the layers to form hydrophobic regions; for all except 3,5-dichloroanilinium chloride, neighbouring layers are linked by weaker interactions such as C-H···Cl hydrogen bonds or Cl···Cl contacts. The final structure, 3,5-dichloroanilinium chloride 1/4-hydrate, is completely different; it involves two types of columns, one built up from quadrilaterals of Cl···Cl contacts between cations and the other consisting of “nanotubes ’ of NH3 groups and chloride anions linked by two- and three-centre hydrogen bonds. The columns are in turn linked by cation-anion Cl···Cl interactions.
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Rajendiran, T. V., and A. Jayanthi. "Activation Energy from Thermogravimetric Analysis of Certain Azopolyamides." Material Science Research India 8, no. 1 (June 25, 2011): 189–95. http://dx.doi.org/10.13005/msri/080127.
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Six new azopolyamides were synthesized from 2, 21–dimethoxy 4, 41–diaminoazobenzene [Benzenamine–(3, 31– dimethoxy–4, 41-azo) bis] condensed with any one of the following diacid chlorides viz. (i) terephthaloyl chloride. (ii) isophthaloyl chloride. (iii) 4, 41–azodibenzoyl chloride (iv) 3, 31-azo dibenzoyl chloride (v) 4, 41–stilbene dicarbonyl chloride and (vi) 4, 41–oxydibenzoyl chloride using low temperature solution method. These polyamides were characterized by thermogravimetric analyses (TGA and DTA). Activation energy has been calculated using Murray and white, coats and Redfern, Doyle's, Freeman and Carroll, Ozawa–Flyn–Waal's and modified Coats and Redfern's method.
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Perera, Nandana, Bahram Gharabaghi, Peter Noehammer, and Bruce Kilgour. "Road Salt Application in Highland Creek Watershed, Toronto, Ontario - Chloride Mass Balance." Water Quality Research Journal 45, no. 4 (November 1, 2010): 451–61. http://dx.doi.org/10.2166/wqrj.2010.044.
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Abstract Occurrence of increasing chloride concentrations in urban streams of cold climates, mainly due to road salt application, has raised concerns on its adverse effects on aquatic and terrestrial ecosystems. Therefore, there is a need for a better understanding of processes associated with road salt application and subsequent discharge into the environment in order to develop management practices to minimize detrimental effects of chlorides. The chloride mass analysis for the Highland Creek watershed based on four years of hourly monitoring data indicates that approximately 60% of the chlorides applied on the watershed enter streams prior to subsequent salting period, 85% of which occurs during the period between November and March. Contribution of private de-icing operations on chloride mass input within Highland Creek watershed was estimated to be approximately 38%, indicating its significance in overall chloride mass balance. Salt application rates, as well as chloride output in the streams, vary spatially based on land use, influencing chloride concentrations in surface waters. The estimated groundwater chloride concentration of 275 mg/L indicates that some aquatic organisms in Highland Creek would potentially be at risk even outside the winter period under dry weather flow conditions.
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Jumanto, Jumanto, Abu Bakar, and Achmad Sigit Sugiharto. "Efektivitas Didecyldimethylammonium Chloride 2.5% dan Chlorine 0.5% terhadap Pertumbuhan Staphylococcus aureus dan Klebsiella pneumoniae di Ruang Operasi." Journal of Telenursing (JOTING) 4, no. 2 (September 16, 2022): 528–35. http://dx.doi.org/10.31539/joting.v4i2.4041.
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This study aims to determine the effectiveness of the disinfection of 0.5% chlorine and 2.5% didecyldimethylammonium chloride against Staphylococcus aureus and Klebsiella pneumoniae in the operating room. The method used is a quasi-experimental post-only group design with a total sample of 40 samples of the operating room environment. The results showed no difference between the two types of disinfectants, namely didecyldimethylammonium chloride 2.5% and chlorine 0.5% in reducing the number of bacteria (p-value 0.373) and both were able to reduce the number of Staphylococcus aureus and Klebsiella pneumoniae. In conclusion, both disinfectants effectively reduced Staphylococcus aureus and Klebsiella pneumoniae on operating room surfaces.
Keywords: Didecyldimethylammonium Chloride Disinfection, Chlorine, Bacterial Growth, Operating Room
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Bhatkar, N. V. "Chromium, nickel and zinc induced histopathological alterations in the gill of Indian common carp Labeo rohita (Ham.)." Journal of Applied and Natural Science 2, no. 2 (December 1, 2010): 234–38. http://dx.doi.org/10.31018/jans.v2i2.126.
Full textAbstract:
Degenerative histopathalogical alterations were seen in gills due to chronic exposure of the fish, Labeo rohita to chlorides of chromium, nickel and zinc for 30 days. However, more severe degenerative changes were observed in case of zinc chloride exposed fish than nickel chloride and chromium chloride treated fishes, indicating more toxic nature of zinc chloride. Mucus secretion over the gill lamellae was seen prominently in all the experimental fishes. However, in zinc chloride treated fish there was excessive mucus secretion after ten days of exposure andafter thirty days, epithelial lifting was seen. In chromium chloride and nickel chloride treated fishes there was basal hyperplasia, which indicated compensatory mechanism in ion regulation to adjust with the toxic stress.
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Lee, Jae-Min, Sung In Hong, Hee Jun Yang, and Dong-Hyuk Jung. "Numerical Modeling of Chloride Transport in Concrete under Cyclic Exposure to Chloride." Materials 15, no. 17 (August 29, 2022): 5966. http://dx.doi.org/10.3390/ma15175966.
Full textAbstract:
Concrete structures under cyclic exposure to chlorides entail a higher risk of embedded steel corrosion along with accelerated ionic ingress from the environment. This study proposes a coupled transport model considering moisture and chloride distribution in concrete to investigate the influence of a cyclic exposure condition on chloride penetration. In this model, pore size distribution to quantify the effective pore space for moisture and chloride mobilizations was determined to establish the governing equation for chloride transport through non-saturated concrete. From the simulation results, the rate of chloride penetration increases with decreasing ambient humidity levels due to the enhanced chloride convection. Finally, the coupled transport model was verified by comparing in-situ data, showing reasonable correlations with 0.83 and 0.93 of determinant coefficients for 22 and 44 years of exposure, respectively, while those obtained from LIFE 365 were much lower.
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Thorell, Helena Danielsson, Katarina Stenklo, Jan Karlsson, and Thomas Nilsson. "A Gene Cluster for Chlorate Metabolism in Ideonella dechloratans." Applied and Environmental Microbiology 69, no. 9 (September 2003): 5585–92. http://dx.doi.org/10.1128/aem.69.9.5585-5592.2003.
Full textAbstract:
ABSTRACT Chlorate reductase has been isolated from the chlorate-respiring bacterium Ideonella dechloratans, and the genes encoding the enzyme have been sequenced. The enzyme is composed of three different subunits and contains molybdopterin, iron, probably in iron-sulfur clusters, and heme b. The genes (clr) encoding chlorate reductase are arranged as clrABDC, where clrA, clrB, and clrC encode the subunits and clrD encodes a specific chaperone. Judging from the subunit composition, cofactor content, and sequence comparisons, chlorate reductase belongs to class II of the dimethyl sulfoxide reductase family. The clr genes are preceded by a novel insertion sequence (transposase gene surrounded by inverted repeats), denoted ISIde1. Further upstream, we find the previously characterized gene for chlorite dismutase (cld), oriented in the opposite direction. Chlorate metabolism in I. dechloratans starts with the reduction of chlorate, which is followed by the decomposition of the resulting chlorite to chloride and molecular oxygen. The present work reveals that the genes encoding the enzymes catalyzing both these reactions are in close proximity.
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MOKIIЕNKO, Andrii, Larysa SPASONOVA, and Oleksandr BONDARCНUK. "ANALYSIS OF METHODS FOR DETERMINATION OF CHLORINE DIOXIDE, CHLORITE AND CHLORATE ANIONS IN DRINKING WATER." Herald of Khmelnytskyi National University. Technical sciences 317, no. 1 (February 23, 2023): 294–99. http://dx.doi.org/10.31891/2307-5732-2023-317-1-294-299.
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The analysis shows that the primary measure for the purification of drinking water is its reliable disinfection with oxidants, which are chlorine and its compounds, chlorine dioxide, ozone. The aim of the article is to analyze the existing methods for determination of chlorine dioxide, chlorite, hypochlorite and chlorate anions in drinking water. To analyze the chlorine dioxide strength solutions (to control the generator performance) the iodometric method (determination of chlorine dioxide concentration, concentration of free chlorine, chlorite and chlorate anions; relative error ≤ 5%) and the method of direct absorption at 445 nm (determination of chlorine dioxide concentration in the range of concentrations of 100-700 mg / l; relative error ≤ 2%) were used. To analyze the residual concentrations of chlorine dioxide, chlorite and hypochlorite anions in their joint presence the titrimetric and photometric methods with N,N-діетил-1,4-фенилендіамінсульфатом (DFD) (error of determination is of 0.05 mg/l) were used as well as iodometric method with photometric determination of iodine at 350 nm in the concentration range 0.01-0.5 mg/l. To analyze the residual concentrations of chlorine dioxide (selective methods), such methods were used: the photometric method with chlorophenol red in the concentration range of 0.02-0.7 mg/l; relative error ≤ 5%; photometric method with chromic violet acid in the concentration range of 0.1-1.5 mg/l. The method of ion chromatography was used to analyze the residual concentrations of chlorite and chlorate anions. Given the necessity for harmonization of domestic regulatory and guidance documentation with European one, it should be considered as necessary to control chlorites and chlorates in drinking water by method of ion chromatography. It is appropriate to conduct research on the approbation of ion chromatography method for the simultaneous determination of chlorites and chlorates in samples of water after its disinfection by various oxidants (sodium hypochlorite, ozone, chlorine dioxide).
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A.Hasan, Amer, Mohammed H. Al-Mashhadani, Wedad H. Al-Dahhan, Rahimi M.Yusop, and Emad A. Yousif. "Recent Approaches to Modify Poly(vinyl chloride) Chemical Structure." Al-Nahrain Journal of Science 25, no. 3 (September 1, 2022): 8–15. http://dx.doi.org/10.22401/anjs.25.3.02.
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Since its first discovery in the nineteenth century, polymer researchers have continued to study poly(vinyl chloride). Its characteristics, such as its thermal instability, are delicate by its structural flaws that result from its containing chlorine atom which is sensitive to UV light as a good leaving group. Many researchers suggested adding various types of organic and inorganic additives as photo and/or thermal stabilizers of poly(vinyl chloride). Recently this work has been expanded by extensive ongoing research to modify the chemical structure of poly(vinyl chloride) by replacing part of the chlorine atoms with other molecules which could enhance its stability against weathering circumstances. The last was carried out not only for common chemical reactions but also to improve the characteristics of poly(vinyl chloride) in particular applications. Basedon reports from the past ten years, this study outlines many of the chemical alterations of poly(vinyl chloride) as well as associated uses. These alterations are organized following the modification of poly(vinyl chloride) through Carbon-Carbon and Carbon-Nitrogen linkages.