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Sample records for alkylbenzene sulfonate las

  1. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    Linear alkylbenzene sulfonate (LAS) found in wastewater is removed in the wastewater treatment facilities by sorption and aerobic biodegradation. The anaerobic digestion of sewage sludge has not been shown to contribute to the removal. The concentration of LAS based on dry matter typically...... increases during anaerobic stabilization due to transformation of easily degradable organic matter. Hence, LAS is regarded as resistant to biodegradation under anaerobic conditions. We present data from a lab-scale semi-continuously stirred tank reactor (CSTR) spiked with linear dodecylbenzene sulfonate (C...

  2. Inhibition of the anaerobic digestion process by linear alkylbenzene sulfonates

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Ahring, Birgitte Kiær

    2002-01-01

    Linear Alkylbenzene Sulfonates (LAS) are the most widely used synthetic anionic surfactants. They are anthropogenic, toxic compounds and are found in the primary sludge generated in municipal wastewater treatment plants. Primary sludge is usually stabilized anaerobically and therefore it is impor......Linear Alkylbenzene Sulfonates (LAS) are the most widely used synthetic anionic surfactants. They are anthropogenic, toxic compounds and are found in the primary sludge generated in municipal wastewater treatment plants. Primary sludge is usually stabilized anaerobically and therefore...... it is important to investigate the effect of these xenobiotic compounds on an anaerobic environment. The inhibitory effect of Linear Alkylbenzene Sulfonates (LAS) on the acetogenic and methanogenic step of the anaerobic digestion process was studied. LAS inhibit both acetogenesis from propionate...

  3. Properties of polypyrrole doped with alkylbenzene sulfonates

    DEFF Research Database (Denmark)

    Bay, Lasse; Skaarup, Steen; West, Keld

    2001-01-01

    -standing 10 mu m thick film is prepared electrochemically at a constant current from an aqueous solution of pyrrole and sodium alkylbenzene sulfonate. The mechanical properties of the film (tensile strength and Young's modulus) and the reversible linear elongation between the oxidised and reduced states...... are measured. Alkylbenzene sulfonates with alkyl chain lengths between 1 and 22 carbon atoms are used as dopant anion. The films made with the different anions have highly different properties and are here compared to outline the influence of the size of the anion. A maximum in linear elongation is found for p......-(n-octyl)benzene sulfonate and in conductivity for p-(n-butyl)benzene sulfonate....

  4. Properties of polypyrrole doped with alkylbenzene sulfonates

    DEFF Research Database (Denmark)

    Bay, Lasse; Skaarup, Steen; West, Keld

    2001-01-01

    -standing 10 mu m thick film is prepared electrochemically at a constant current from an aqueous solution of pyrrole and sodium alkylbenzene sulfonate. The mechanical properties of the film (tensile strength and Young's modulus) and the reversible linear elongation between the oxidised and reduced states...

  5. Inhibition of the anaerobic digestion process by linear alkylbenzene sulfonates

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Ahring, Birgitte Kiær

    2002-01-01

    it is important to investigate the effect of these xenobiotic compounds on an anaerobic environment. The inhibitory effect of Linear Alkylbenzene Sulfonates (LAS) on the acetogenic and methanogenic step of the anaerobic digestion process was studied. LAS inhibit both acetogenesis from propionate...... of the anaerobic digestion process should be seriously taken into consideration when wastewater from a surfactant producing industry is to be treated biologically or enter a municipal wastewater treatment plant that employs anaerobic technology. The upper allowable biomass specific LAS concentration should be 14......Linear Alkylbenzene Sulfonates (LAS) are the most widely used synthetic anionic surfactants. They are anthropogenic, toxic compounds and are found in the primary sludge generated in municipal wastewater treatment plants. Primary sludge is usually stabilized anaerobically and therefore...

  6. Anaerobic degradation of linear alkylbenzene sulfonate in fluidized bed reactor

    Directory of Open Access Journals (Sweden)

    L. L. Oliveira

    2010-12-01

    Full Text Available An anaerobic fluidized bed reactor was used to assess the degradation of the surfactant linear alkylbenzene sulfonate (LAS. The reactor was inoculated with sludge from an UASB reactor treating swine wastewater and was fed with a synthetic substrate supplemented with LAS. Sand was used as support material for biomass immobilization. The reactor was kept in a controlled temperature chamber (30±1 ºC and operated with a hydraulic retention time (HRT of 18 h. The LAS concentration was gradually increased from 8.2±1.3 to 45.8±5.4 mg.L-1. The COD removal was 91%, on average, when the influent COD was 645±49 mg.L-1. The results obtained by chromatographic analysis showed that the reactor removed 93% of the LAS after 270 days of operation.

  7. Screening test for assessment of ultimate biodegradability: linear alkylbenzene sulfonates.

    Science.gov (United States)

    Gledhill, W E

    1975-01-01

    A relatively simple shake-flask system for determining CO2 evolution was developed to assess the ultimate biodegradability by soil and sewage micro-organisms of chemicals which enter the environment. Linear alkylbenzene sulfonates (LAS) were used as model compounds to evaluate the method and were found to undergo substantial biodegradation in this dilute system. At the 30 mg/liter test concentration, higher-molecular-weight LAS compounds were biodegraded at a slower rate and to a lesser extent than lower-molecular-weight LAS, an effect which was eliminated or greatly reduced upon incremental addition of the LAS to the test medium during the first week of incubation. LA35S was used to demonstrate rapid LAS desulfonation, and 14CO2 evolution studies with (14C) benzene ring-labeled LAS indicated concomitant biodegradation of the entire LAS molecule as well as the LAS aromatic component. The test can be employed to examine numerous compounds at the same time and is readily adapted to studies of the effect of variation in temperature and oxygen concentration on biodegradation. PMID:1211937

  8. Formation of metabolites during biodegradation of linear alkylbenzene sulfonate in an upflow anaerobic sludge bed reactor under thermophilic conditions

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Ahring, Birgitte Kiær

    2002-01-01

    Biodegradation of linear alkylbenzene sulfonate (LAS) was shown in an upflow anaerobic sludge blanket reactor under thermophilic conditions. The reactor was inoculated with granular biomass and fed with a synthetic medium and 3 mumol/L of a mixture of LAS with alkylchain length of 10 to 13 carbon...

  9. Anaerobic degradation of linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Haagensen, Frank; Ahring, Birgitte Kiær

    2003-01-01

    % of the added C-12 LAS was bioavailable and 20% was biotransformed when spiking with 100 mg/L of C-12 LAS and a TS concentration of 14.2 mg/L. Enhanced bioavailability of C-12 LAS was obtained in an upflow anaerobic sludge blanket (UASB) reactor inoculated with granular sludge and sewage sludge. Biodegradation...... under thermophilic conditions was 37% with LAS as sole carbon source. Benzaldehyde was produced in the UASB reactor during LAS transformation....

  10. Effect of Linear Alkylbenzene Sulfonate on Mortality, Hatching Rate of Eggs and Abnormality of Catfish (Pangasius hypophthalmus Sauvage Larvae

    Directory of Open Access Journals (Sweden)

    E. Supriyono

    2007-01-01

    Full Text Available Linear alkylbenzene sulfonate (LAS surfactant in the water can affecting fish in all developmental stages.  This study was aimed to observe the effect of LAS on mortality, hatching rate of eggs, and abnormality of patin catfish (Pangasius hypophthalmus Sauvage larvae.   Fertilized eggs were incubated in water containing LAS at the dosages of 0.0, 0.5, 1.5, 3.0, 9.0, and 18.0 mg/L.  Eggs mortality was observed every 6 hours until larvae hatched (24 hours.  The results of study showed that the exposure of 18.0 mg LAS per liter water could put to death all the fertilized eggs and larvae be abnormal.  The exposure of LAS at concentration of 9.0 mg/L could kill 98% of eggs and hatching rate was only 2%.  The abnormality in larvae was bending in the body and tails. Keywords: patin catfish, Pangasius, Linear Alkylbenzene Sulfonate, LAS, abnormality   ABSTRAK Surfaktan Linear Alkylbenzene Sulfonate (LAS yang masuk ke dalam perairan sangat berpengaruh terhadap ikan dari stadia awal hidup ikan sampai dewasa. Penelitian ini bertujuan untuk mengetahui pengaruh LAS terhadap mortalitas, daya tetas telur dan abnormalitas larva ikan patin (Pangasius hypophthalmus Sauvage.  Telur ikan patin yang telah dibuahi di rendam dalam air yang mengandung LAS dengan konsentrasi 0,0; 0,5; 1,5; 3,0; 9,0 dan 18,0 mg/L.  Mortalitas telur dicatat setiap 6 jam sampai menetas (24 jam.  Hasil penelitian menunjukkan bahwa konsentrasi LAS sebesar 18,0 mg/L dapat mengakibatkan mortalitas telur dan abnormalitas pada larva secara total.  Konsentrasi LAS sebesar 9,0 mg/L dapat mematikan telur hingga 98% dan hanya menghasilkan daya tetas sebanyak 2%. Abnormalitas pada larva berupa pembengkokan pada tubuh dan ekor. Kata kunci: ikan patin, Pangasius, Linear Alkylbenzene Sulfonate, LAS dan abnormalitas

  11. Mineralization of linear alkylbenzene sulfonate by a four-member aerobic bacterial consortium

    International Nuclear Information System (INIS)

    Jimenez, L.; Breen, A.; Thomas, N.; Sayler, G.S.; Federle, T.W.

    1991-01-01

    A bacterial consortium capable of linear alkylbenzene sulfonate (LAS) mineralization under aerobic conditions was isolated from a chemostat inoculated with activated sludge. The consortium, designated KJB, consisted of four members, all of which were gram-negative, rod-shaped bacteria that grew in pairs and short chains. Three isolates had biochemical properties characteristic of Pseudomonas spp.; the fourth showed characteristics of the Aeromonas spp. Cell suspensions were grown together in minimal medium with [ 14 C]LAS as the only carbon source. After 13 days of incubation, more than 25% of the [ 14 C]LAS was mineralized to 14 CO 2 by the consortium. Pure bacterial cultures and combinations lacking any one member of the KJB bacterial consortium did not mineralize LAS. Three isolates carried out primary biodegradation of the surfactant, and one did not. This study shows that the four bacteria complemented each other and synergistically mineralized LAS, indicating catabolic cooperation among the four consortium members

  12. The Use of Multi-Reactor Cascade Plasma Electrolysis for Linear Alkylbenzene Sulfonate Degradation

    Science.gov (United States)

    Saksono, Nelson; Ibrahim; Zainah; Budikania, Trisutanti

    2018-03-01

    Plasma electrolysis is a method that can produce large amounts of hydroxyl radicals to degrade organic waste. The purpose of this study is to improve the effectiveness of Linear alkylbenzene sulfonate (LAS) degradation by using multi-reactor cascade plasma electrolysis. The reactor which operated in circulation system, using 3 reactors series flow and 6 L of LAS with initial concentration of 100 ppm. The results show that the LAS degradation can be improved multi-reactor cascade plasma electrolysis. The greatest LAS degradation is achieved up to 81.91% with energy consumption of 2227.34 kJ/mmol that is obtained during 120 minutes by using 600 Volt, 0.03 M of KOH, and 0.5 cm of the anode depth.

  13. Liquid Phase Micro-Extraction of Linear Alkylbenzene Sulfonate Anionic Surfactants in Aqueous Samples

    Directory of Open Access Journals (Sweden)

    Jan Åke Jönsson

    2011-10-01

    Full Text Available Hollow fiber liquid phase micro-extraction (LPME of linear alkylbenzene sulfonates (LAS from aqueous samples was studied. Ion pair extraction of C10, C11, C12 and C13 homologues was facilitated with trihexylamine as ion-pairing agent, using di-n-hexylether as solvent for the supported liquid membrane (SLM. Effects of extraction time, acceptor buffer concentration, stirring speed, sample volume, NaCl and humic acids were studied. At 10–50 µg L−1 linear R2-coefficients were 0.99 for C10 and C11 and 0.96 for C12. RSD was typically ~15%. Three observations were especially made. Firstly, LPME for these analytes was unusually slow with maximum enrichment observed after 15–24 h (depending on sample volume. Secondly, the enrichment depended on LAS sample concentration with 35–150 times enrichment below ~150 µg L−1 and 1850–4400 times enrichment at 1 mg L−1. Thirdly, lower homologues were enriched more than higher homologues at low sample concentrations, with reversed conditions at higher concentrations. These observations may be due to the fact that LAS and the amine counter ion themselves influence the mass transfer at the water-SLM interface. The observations on LPME of LAS may aid in LPME application to other compounds with surfactant properties or in surfactant enhanced membrane extraction of other compounds.

  14. Formation of metabolites during biodegradation of linear alkylbenzene sulfonate in an upflow anaerobic sludge bed reactor under thermophilic conditions

    DEFF Research Database (Denmark)

    Mogensen, Anders Skibsted; Ahring, Birgitte Kiær

    2002-01-01

    , the removal of LAS in the reactor inoculated with active granular biomass exceeded the removal in the sterile reactor inoculated with sterile granular biomass. The effect of sorption ceased after 185 to 555 h depending on the LAS homologs. 40% of the LAS was biodegraded, and the removal rate was 0.5 x 10......Biodegradation of linear alkylbenzene sulfonate (LAS) was shown in an upflow anaerobic sludge blanket reactor under thermophilic conditions. The reactor was inoculated with granular biomass and fed with a synthetic medium and 3 mumol/L of a mixture of LAS with alkylchain length of 10 to 13 carbon...... atoms. The reactor was operated with a hydraulic retention time of 12 h with effluent recirculation in an effluent to influent ratio of 5 to 1. A sterile reactor operated in parallel revealed that sorption to sludge particles initially accounted for a major LAS removal. After 8 days of reactor operation...

  15. Environmental monitoring study of linear alkylbenzene sulfonates and insoluble soap in Spanish sewage sludge samples.

    Science.gov (United States)

    Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Reis, Marco S; Saraiva, Pedro M; Vílchez, José L

    2011-01-01

    In this work we present a monitoring study of linear alkylbenzene sulfonates (LAS) and insoluble soap performed on Spanish sewage sludge samples. This work focuses on finding statistical relations between LAS concentrations and insoluble soap in sewage sludge samples and variables related to wastewater treatment plants such as water hardness, population and treatment type. It is worth to mention that 38 samples, collected from different Spanish regions, were studied. The statistical tool we used was Principal Component Analysis (PC), in order to reduce the number of response variables. The analysis of variance (ANOVA) test and a non-parametric test such as the Kruskal-Wallis test were also studied through the estimation of the p-value (probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true) in order to study possible relations between the concentration of both analytes and the rest of variables. We also compared LAS and insoluble soap behaviors. In addition, the results obtained for LAS (mean value) were compared with the limit value proposed by the future Directive entitled "Working Document on Sludge". According to the results, the mean obtained for soap and LAS was 26.49 g kg(-1) and 6.15 g kg(-1) respectively. It is worth noting that LAS mean was significantly higher than the limit value (2.6 g kg(-1)). In addition, LAS and soap concentrations depend largely on water hardness. However, only LAS concentration depends on treatment type.

  16. Microbial characterization and degradation of linear alkylbenzene sulfonate in an anaerobic reactor treating wastewater containing soap powder.

    Science.gov (United States)

    Carosia, Mariana Fronja; Okada, Dagoberto Yukio; Sakamoto, Isabel Kimiko; Silva, Edson Luiz; Varesche, Maria Bernadete Amâncio

    2014-09-01

    The aim of this study was to evaluate the removal of linear alkylbenzene sulfonate (LAS) in an anaerobic fluidized bed reactor (AFBR) treating wastewater containing soap powder as LAS source. At Stage I, the AFBR was fed with a synthetic substrate containing yeast extract and ethanol as carbon sources, and without LAS; at Stage II, soap powder was added to this synthetic substrate obtaining an LAS concentration of 14 ± 3 mg L(-1). The compounds of soap powder probably inhibited some groups of microorganisms, increasing the concentration of volatile fatty acids (VFA) from 91 to 143 mg HAc L(-1). Consequently, the LAS removal rate was 48 ± 10% after the 156 days of operation. By sequencing, 16S rRNA clones belonging to the phyla Proteobacteria and Synergistetes were identified in the samples taken at the end of the experiment, with a remarkable presence of Dechloromonas sp. and Geobacter sp. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Matrix effect study in the determination of linear alkylbenzene sulfonates in sewage sludge samples.

    Science.gov (United States)

    Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Vílchez, José L; Verge, Coral; De Ferrer, Juan A

    2011-04-01

    We propose a study of the matrix effect in the determination of linear alkylbenzene sulfonates (LAS) in sewage sludge samples. First, a rapid, selective and sensitive method is proposed. The method involves two stages: the extraction of the compound from the samples and analysis by liquid chromatography with fluorescence detection (LC-FLD). Three different techniques of extraction (microwave-assisted extraction, Soxhlet, and ultrasounds) were compared, and microwave-assisted extraction was selected as the best suited for our purpose. Microwave-assisted extraction allows reducing the extraction time (25 min compared with 12 h for conventional Soxhlet extraction) and solvent waste (25 ml of methanol compared with 200 ml for Soxhlet or more than 50 ml for the ultrasonic procedure). Absence of matrix effect was evaluated with two standards (2ØC(8:0) and 2ØC(16:0) ) that are not commercial; therefore, neither of them was detected in sewage sludge samples and they showed similar environmental behavior (adsorption and precipitation) to LAS (C(11:0) -C(13.0) ), which allow us to evaluate the matrix effect. Validation was carried out by a recovery assay, and the method was applied to samples from different sources; therefore, they had different compositions. Copyright © 2011 SETAC.

  18. Response of weeping willows to linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Yu, X.; Trapp, Stefan; Zhou, P.

    2006-01-01

    in hydroponic solution spiked with LAS at 24.0 +/- 1 degrees C for 192 h. The normalized relative transpiration of plants was used to determine toxicity. Severe reduction of the transpiration was only found for high doses of LAS (>= 240 mg 1(-1)). Chlorophyll contents in leaves of treated plants varied...

  19. Bioremediation of surface water co-contaminated with zinc (II) and linear alkylbenzene sulfonates by Spirulina platensis

    Science.gov (United States)

    Meng, Huijuan; Xia, Yunfeng; Chen, Hong

    Potential remediation of surface water contaminated with linear alkylbenzene sulfonates (LAS) and zinc (Zn (II)) by sorption on Spirulina platensis was studied using batch techniques. Results show that LAS can be biodegraded by Spirulina platensis, and its biodegradation rate after 5 days was 87%, 80%, and 70.5% when its initial concentration was 0.5, 1, and 2 mg/L, respectively. The maximum Zn (II) uptake capacity of Spirulina platensis was found to be 30.96 mg/g. LAS may enhance the maximum Zn (II) uptake capacity of Spirulina platensis, which can be attributed to an increase in bioavailability due to the presence of LAS. The biodegradation rates of LAS by Spirulina platensis increased with Zn (II) and reached the maximum when Zn (II) was 4 mg/L. The joint toxicity test showed that the combined effect of LAS and Zn (II) was Synergistic. LAS can enhance the biosorption of Zn (II), and reciprocally, Zn (II) can enhance LAS biodegradation.

  20. Effects of microcystin-LR, linear alkylbenzene sulfonate and their mixture on lettuce (Lactuca sativa L.) seeds and seedlings.

    Science.gov (United States)

    Wang, Zhi; Xiao, Bangding; Song, Lirong; Wu, Xingqiang; Zhang, Junqian; Wang, Chunbo

    2011-06-01

    Microcystin-LR (MCLR) and linear alkylbenzene sulfonate (LAS) are present widely in aquatic and terrestrial ecosystems, but their combined ecotoxicological risk is unknown. This study investigated the toxic effects of MCLR, LAS and their mixture on lettuce (Lactuca sativa L.) and evaluated MCLR accumulation level in lettuce with or without LAS. The changes in seed germination and shoot/root growth, responses of the antioxidative defense system, and the accumulation of MCLR in lettuce were tested to evaluate the single and combined toxic effect of MCLR and LAS in well-controlled conditions. The results showed that seedling growth (except for root elongation and leaf weight) was more sensitive to toxicant exposure than seed germination. For seedling leaves, lipid peroxidation was not observed when the antioxidative defense system (including superoxide dismutase, catalase and glutathione) was activated to relieve the adverse effects of oxidative stress via different pathways. Our results also confirmed that the interaction between MCLR and LAS was synergistic. Both toxicants in combination not only significantly inhibited seedling growth, but also increased the activities of superoxide dismutase and catalase, as well as the contents of glutathione. Furthermore, LAS dramatically enhanced the accumulation of MCLR in the plant, thus leading to a reduction in quality and yield and posing greater potential risk to humans via consumption of these edible plants.

  1. Cellular and molecular hypoxic response in common carp (Cyprinus carpio) exposed to linear alkylbenzene sulfonate at sublethal concentrations.

    Science.gov (United States)

    Tasaki, Junichi; Nakayama, Kei; Shimizu, Ichiyo; Yamada, Hiroko; Suzuki, Takahiro; Nishiyama, Naohiro; Yamane, Masayuki

    2017-01-01

    Linear alkylbenzene sulfonate (LAS) is an anionic surfactant commonly used in cleaning agents such as laundry detergents. Trace amounts of LAS are released into environmental waters after processing in wastewater treatment plants after the use of this chemical. Acute toxicity of LAS has been well-studied using various organisms, and its effects are particularly well known in fish. LAS damages fish gill morphology and induces mucous excretion from these organs. LAS also causes hematological changes. These observations suggest that LAS might induce hypoxic conditions in fish. However, the connections between hypoxia and hematological changes at the cellular and molecular levels remain unknown. Common carp were exposed to LAS at concentrations of 625, 1250, and 2500 μg/L for 96 h. A total of 9-10 fish were sampled at the end of the exposure period for each concentration. For hematological analysis, carp blood was sampled from the caudal vein. Gill tissue was used for real-time PCR analysis to evaluate transcriptional changes of hypoxia-induced genes. The number of normal red blood cells and the number of immature red blood cells were significantly decreased and increased, respectively, in fish exposed to 2500 µg/L LAS. The hypoxic marker genes hypoxia inducible factor 1α, myoglobin 1, and erythropoietin 2 were upregulated in these fish. Our results suggest that LAS decreases erythrocyte numbers and induces hypoxic conditions. In addition, LAS-exposed fish increase production of immature erythrocytes and upregulate myoglobin expression in gills to improve oxygen transport and absorption. © 2015 Wiley Periodicals, Inc. Environ Toxicol 32: 122-130, 2017. © 2015 Wiley Periodicals, Inc.

  2. Screening method for linear alkylbenzene sulfonates in sediments based on water Soxhlet extraction assisted by focused microwaves with on-line preconcentration/derivatization/detection.

    Science.gov (United States)

    Morales-Muñoz, S; Luque-García, J L; de Castro, Luque

    2004-02-13

    A screening method for linear alkylbenzene sulfonates (LAS) in sediments has been developed. Soxhlet extraction with water assisted by focused microwaves provides recoveries better (>90%) than obtained by conventional Soxhlet extraction (70-80%). Coupling of the extractor with an on-line preconcentration/derivatization/detection manifold through a flow injection (FI) interface allows a fully automated screening approach. A yes/no answer can be obtained in less than 2 h (for the whole analytical process), a short time compared with the at least 24 h of Soxhlet extraction (without final detection). Due to the use of water as leaching agent, the proposed method is environmentally friendly.

  3. Linear Alkylbenzene Sulfonate tolerance in bacteria isolated from sediment of tropical water bodies polluted with detergents

    Directory of Open Access Journals (Sweden)

    I.T Kehinde

    2008-12-01

    Full Text Available The discharge of untreated detergent-bearing waste introduces linear alkylbenzene sulfonates (LAS to the aquatic environment. The surfactant persists in some streams and rivers in Nigeria, some is adsorbed to suspended materials and end in the sediment of the receiving water bodies. In this study, bacteria isolated from sediments of some tropical detergent-effluent-polluted streams were tested for tolerance to LAS using the media dilution technique. LAS-tolerance was indicated by growth of the bacteria in the presence of the surfactant. The pH, concentrations of surfactant, population of heterotrophic bacteria and population of LAS-tolerant bacteria in the sediments were determined. A direct relationship (r= 0.9124 was found between the alkaline conditions (pH= 8.2-12.0 and high surfactant concentrations (45-132 mg/g in the sediment. The sediments harboured a high population and a wide variety of bacteria; the populations of viable heterotrophic bacteria (vHB: 2.9×10(5 to 1.2×10(7 cfu/g and LAS tolerant bacteria (LTB: 1.5×10(4 to 1.2×10(6 cfu/g had a direct relationship (r= 0.9500. An inverse relationship resulted between each of them and the concentration of surfactant in the sediment, r vHB/ LAS = -0.9303 and rLTB/ LAS = -0.9143, respectively. Twelve bacteria species were isolated from the sediment: Alcaligenes odorans, Bacillus subtilis, Burkholderia cepacia, Citrobacter freundii, Citrobacter diversus, Escherichia coli, Micrococcus luteus, Micrococcus albus, Pseudomonas putida, Pseudomonas stutzeri, Staphylococcus aureus and Streptococcus faecalis. Most of them were adapted to the surfactant with their maximum acceptable concentrations ranging between 0.03 and >1.0% (w/v. The sediments could serve as source of adapted organisms which can be used in bio-treatment of LAS-bearing waste. Rev. Biol. Trop. 56 (4:7-15. Epub 2008 December 12.La descarga de desechos que contienen detergentes liberan sulfonatos de alquibenceno lineal (LAS al

  4. Activity and population dynamics of heterotrophic and ammonia-oxidizing microorganisms in soil surrounding sludge bands spiked with linear alkylbenzene sulfonate

    DEFF Research Database (Denmark)

    Brandt, K. K.; Sørensen, J.; Krogh, P. H.

    2003-01-01

    in a sandy soil surrounding well-defined sludge bands spiked with high but realistic LAS levels (7.1 or 31.3 g/kg). Surprisingly, LAS had no effect on heterotrophic respiration in the sludge compartment per se but stimulated activity and metabolic quotient (microbial activity per unit of biomass......Recent research has documented soil microorganisms to be rather sensitive to linear alkylbenzene sulfonates (LAS), which may enter the soil environment in considerable quantities following sewage sludge disposal. We here report field effects of LAS on selected microbial populations present......) in the surrounding soil. By contrast, autotrophic ammonia oxidation was initially inhibited in the LAS-spiked sludge. This led to dramatic transient increases of NH+4 availability in the sludge and surrounding soil, subsequently stimulating soil ammonia oxidizers. As judged from a Nitrosomonas europaea...

  5. New extraction method for the analysis of linear alkylbenzene sulfonates in marine organisms. Pressurized liquid extraction versus Soxhlet extraction.

    Science.gov (United States)

    Alvarez-Muñoz, D; Sáez, M; Lara-Martin, P A; Gómez-Parra, A; González-Mazo, E

    2004-10-15

    A new method has been developed for the determination of linear alkylbenzene sulfonates (LAS) from various marine organisms, and compared with Soxhlet extraction. The technique applied includes the use of pressurized liquid extraction (PLE) for the extraction stage, preconcentration of the samples, purification by solid-phase extraction (SPE) and analysis by liquid chromatography with fluorescence detection. The spiked concentrations were added to the samples (wet mass of the organisms: Solea senegalensis and Ruditapes semidecussatus), which were homogenized and agitated continuously for 25 h. The samples were extracted by pressurized hot solvent extraction using two different extraction temperatures (100 and 150 degrees C) and by traditional Soxhlet extraction. The best recoveries were obtained employing pressurized hot solvent extraction at 100 degrees C and varied in the range from 66.1 to 101.3% with a standard deviation of between 2 and 13. Detection limit was between 5 and 15 microg kg(-1) wet mass using HPLC-fluorescence detection. The analytical method developed in this paper has been applied for LAS determination in samples from a Flow-through exposure system with the objective of measuring the bioconcentration of this surfactant.

  6. Linear alkylbenzene sulfonate tolerance in bacteria isolated from sediment of tropical water bodies polluted with detergents.

    Science.gov (United States)

    Eniola, Kehinde I T; Olayemi, Albert B

    2008-12-01

    The discharge of untreated detergent-bearing waste introduces linear alklcylbenzene sulfonates (LAS) to the aquatic environment. The surfactant persists in some streams and rivers in Nigeria, some is adsorbed to suspended materials and end in the sediment of the receiving water bodies. In this study, bacteria isolated from sediments of some tropical detergent-effluent-polluted streams were tested for tolerance to LAS using the media dilution technique. LAS-tolerance was indicated by growth of the bacteria in the presence of the surfactant. The pH, concentrations of surfactant, population of heterotrophic bacteria and population of LAS-tolerant bacteria in the sediments were determined. A direct relationship (r = 0.9124) was found between the alkaline conditions (pH= 8.2-12.0) and high surfactant concentrations (45-132 mg/g) in the sediment. The sediments harboured a high population and a wide variety of bacteria; the populations of viable heterotrophic bacteria (VHB: 2.9 x 10(5) to 1.2 x 10(7) cfu/g) and LAS tolerant bacteria (LTB: 1.5 x 10(4) to 1.2 x 10(6) cfu/g) had a direct relationship (r = 0.9500). An inverse relationship resulted between each of them and the concentration of surfactant in the sediment, r(VHB/LAS) = -0.9303 and r(LTB/LAS) = -0.9143, respectively. Twelve bacteria species were isolated from the sediment: Alcaligenes odorans, Bacillus subtilis, Burkholderia cepacia, Citrobacter freundii, Citrobacter diversus, Escherichia coli, Micrococcus luteus, Micrococcus albus, Pseudomonas putida, Pseudomonas stutzeri, Staphylococcus aureus and Streptococcusfaecalis. Most of them were adapted to the surfactant with their maximum acceptable concentrations ranging between 0.03 and >1.0% (w/v). The sediments could serve as source of adapted organisms which can be used in bio-treatment of LAS-bearing waste.

  7. Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps

    DEFF Research Database (Denmark)

    Clausen, S K; Sobhani, S; Poulsen, O M

    2000-01-01

    The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice. The surfact......The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice...... showed a statistically significant increase in OVA specific IgE levels. After two boosters, a statistically significant suppression in OVA-specific IgE production occurred with SDS (1000 mg/l), SDBS (1000 and 100 mg/l), coconut soap (1000 mg/l) and the alcohol ethoxylate (10 mg/l). This study suggests...

  8. Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps

    DEFF Research Database (Denmark)

    Clausen, S K; Sobhani, S; Poulsen, O M

    2000-01-01

    The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice....... The surfactants were injected subcutaneously (sc) in concentrations of 1000, 100, 10 or 1 mg/l, respectively, together with 1 microg of ovalbumin (OVA). In addition, groups of mice received OVA in saline (control group) or in Al(OH)(3) (positive adjuvant control group). After the primary immunization the mice...... that a limited number of surfactants possess an adjuvant effect whereas all surfactants at certain levels can suppress specific IgE production....

  9. Study of adjuvant effect of model surfactants from the groups of alkyl sulfates, alkylbenzene sulfonates, alcohol ethoxylates and soaps.

    Science.gov (United States)

    Clausen, S K; Sobhani, S; Poulsen, O M; Poulsen, L K; Nielsen, G D

    2000-11-01

    The sodium salts of representatives of anionic surfactants, dodecylbenzene sulfonate (SDBS), dodecyl sulfate (SDS) and coconut oil fatty acids, and a nonionic surfactant, dodecyl alcohol ethoxylate, were studied for adjuvant effect on the production of specific IgE antibodies in mice. The surfactants were injected subcutaneously (sc) in concentrations of 1000, 100, 10 or 1 mg/l, respectively, together with 1 microg of ovalbumin (OVA). In addition, groups of mice received OVA in saline (control group) or in Al(OH)(3) (positive adjuvant control group). After the primary immunization the mice were boosted up to three times with OVA (0.1 microg sc) in saline. OVA-specific IgE antibodies were determined by the heterologous mouse rat passive cutaneous anaphylaxis test. The results were confirmed by a specific ELISA method. After the first booster, the Al(OH)(3) group and the 10 mg/l SDS group showed a statistically significant increase in OVA specific IgE levels. After two boosters, a statistically significant suppression in OVA-specific IgE production occurred with SDS (1000 mg/l), SDBS (1000 and 100 mg/l), coconut soap (1000 mg/l) and the alcohol ethoxylate (10 mg/l). This study suggests that a limited number of surfactants possess an adjuvant effect whereas all surfactants at certain levels can suppress specific IgE production.

  10. Can Early Life-Stages of the Marine Fish Sparus aurata be Useful for the Evaluation of the Toxicity of Linear Alkylbenzene Sulphonates Homologues (LAS C10-C14 and Commercial LAS?

    Directory of Open Access Journals (Sweden)

    M. Hampel

    2002-01-01

    Full Text Available Most commercial household cleaning agents and personal care products contain the anionic surfactant linear alkylbenzene sulphonates (LAS as the active compound. After their use they are discharged, theoretically after adequate wastewater treatment, into receiving waters finally reaching estuaries and coastal waters. Laboratory toxicity tests are useful tools in determining at which concentration a certain wastewater compound becomes hazardous for an existing group of organisms. Early life-stage toxicity tests include exposure during the most sensitive development period of the organism. In fish, this type of assay has shown to predict accurately maximum acceptable toxicant concentration (MATC values (comprised in the range defined by the NOEC and LOEC in fish early life-stage tests. For this reason, larvae of the seabream, Sparus aurata, were exposed to increasing concentrations of LAS homologues (C10-C14 and commercial LAS. Obtained LC50 values ranged between 0.1 and 3.0 mg l-1 and were compared with LC50 values of previous hatching experiments with the same species. Larvae proved to be more sensitive to LAS exposure of individual homologues than eggs, except in the case of commercial LAS. LC50 values can be directly employed to determine their potential risk in a concrete environment with known pollutant concentrations. Dividing the LC50 value with the found homologue concentration and extrapolating with certain security factors proposed by different environmental organisms, potentially hazardous pollutant concentrations may be detected. Average estuarine or coastal LAS concentrations are generally below toxicity limits for this kind of organism, considering that the average alkyl chain length of commercial LAS is 11.6 carbon atoms.

  11. Removal Efficiency of Linear Alkyl Benzene Sulfonate (LAS in Yazd Stabilization Pond

    Directory of Open Access Journals (Sweden)

    Asghar Ebrahimi

    2011-01-01

    Full Text Available Surfactants are organic chemicals with wide applications as detergents. Linear alkyl benzene sulfonate (LAS is an anionic surfactant most commonly used. Discharge of raw or treated wastewater containing this chemical into the environment causes major public health problems. In this study, 64 samples were taken from the effluent of Yazd Wastewater  Treatment Plant over a period of one year. The samples were analyzed according to standard methods. The results obtained from the samples taken in different seasons showed that the highest efficiency of anionic surfactant removal was achieved in the summer in the secondary facultative stabilization pond. The least efficiency was observed in the autumn in samples from the anaerobic stabilization pond. It was also found that treated wastewater discharged into surface waters, reused for agricultural irrigation, or discharged into absorbent wells had significant differences with Pvalue

  12. Alkyl-benzene-sulfonates; Alkylbenzenesulfonates

    Energy Technology Data Exchange (ETDEWEB)

    Marcou, L. [Ecole Superieure de Physique et Chimie Industrielles, 75 - Paris (France)]|[CEN, Comite europeen de normalisation (France)]|[Syndicat francais des producteurs d`agents de surface et produits auxiliaires industriels (ASPA) (France)

    1998-03-01

    The alkyl-benzene-sulfonates, or sulfophenyl-4-alkanes salts, (ABS) are anionic surface agents whose chemical formula is R-C{sub 6} H{sub 4}-SO{sub 3} M (where R is an aliphatic hydro-carbonated radical and M a metal). Like most of the surface agents, the ABS are complicated mixtures of isomers and homologues, the most usual products having 10 or 13 atoms of carbons. Their chemical preparation is carried out in two steps: 1)the alkyl-benzenes production by the alkanes or alkenes condensation on benzene 2)the alkyl-benzenes sulfonation and the neutralization of the sulfonic acids. The environmental impacts of these compounds are also given. (O.M.) 11 refs.

  13. Risk assessment of linear alkylbenzene sulphonates, LAS, in agricultural soil revisited: Robust chronic toxicity tests for Folsomia candida (Collembola), Aporrectodea caliginosa (Oligochaeta) and Enchytraeus crypticus (Enchytraeidae)

    DEFF Research Database (Denmark)

    Krogh, P. H.; Lopez, C. V.; Cassani, G.

    2007-01-01

    was not affected by concentrations up to 120 mg LAS kg-1 soil. When adding (low contaminated) non-spiked sludge to soil, high stimulation of reproduction was ob-served for E. crypticus and A. caliginosa but not for F. candida. We argue that this difference in stimulative response between the tested species......To obtain robust data on the toxicity of LAS, tests with the collembolan Folsomia candida L., the oligochaetes Aporrectodea caliginosa Savigny (earthworm) and Enchytraeus crypticus Westheide and Graefe (enchytraeid) were performed in a sandy loam soil. Additionally limited tests with LAS spiked...... to sewage sludge, and subsequently mixed into soil, were performed. For the endpoint of interest, reproduction in soil, we found an EC10 of 205 mg LAS kg-1 soil [8.6-401] [95% confidence limits] for F. candida and an EC10 of 46 mg LAS kg-1 soil [13-80] for A. caliginosa after 28 days. E. crypticus...

  14. A study of anaerobic biodegradation of pure homologue and isomers of linear alkylbenzene sulphonate (LAS) in batch digesters; Estudio de la biodegradacion anaerobia de homologos e isomeros puros de alquibenceno sulfonatos lineales (LAS) en digestores discontinuos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M. T.; Campos, E.; Illan, P.; Dalman, M.; Sanchez-Leal, J.

    2005-07-01

    In the present work the effect of different structural parameters on the anaerobic degradation of the LAS molecule has been studied. so, the effect both of the alkyl chain length and the phenyl position on the anaerobic degradation of the LAS molecule have been investigated. The behaviour of the individual homologues and isomers was studied applying discontinuous anaerobic tests (ECETOC-28). Sludge from the anaerobic digester of the waste water treatment plant of Manresa (Barcelona) was used as bacterial inoculum source. All the LAS homologues showed a poor primary biodegradation. In addition, no effect of the LAS isomer type was found on the anaerobic degradation kinetics. (Author) 6 refs.

  15. Anaerobic treatment of sludge: focusing on reduction of LAS concentration in sludge

    DEFF Research Database (Denmark)

    Haagensen, Frank; Mogensen, Anders Skibsted; Angelidaki, Irini

    2002-01-01

    of transformation varied between 14% and 25%. HPLC analysis showed that disappearance of LAS12 was followed by the formation of a metabolite. The experiments indicated that there is a clear correlation between degradation of organic matter contained in sludge and transformation of LAS12. When the reduction degree......Anaerobic degradation of linear alkylbenzene sulfonates (LAS) was tested in continuous stirred tank reactors (CSTR). LAS12 was used as a model compound and was spiked on sewage sludge. The experiments clearly showed that transformation of LAS12 occurred under anaerobic conditions. The degree...... of the organic matter increased from 22% to 28%, the transformation degree of LAS12 also increased, from 14% to 20%. Decreasing the total solids concentration of the influent sludge or increasing the spiked concentration of LAS12 did not alter the degree of LAS12 transformation significantly. A clear correlation...

  16. Fungal metabolism of n-alkylbenzenes

    Energy Technology Data Exchange (ETDEWEB)

    Fedorak, P.M.; Westlake, D.W.S.

    1986-02-01

    Isolates of Paecilomyces, Verticillium, Beauveria, and Penicillium species were tested for ability to metabolize a variety of n-alkylbenzenes. Minimum side chain lengths were required for metabolism of these substrates. These were C/sub 4/ for the Paecilomyces sp., C/sub 8/ for the Verticillium sp., and C/sub 9/ for the other two isolates. Growth on dodecylbenzene yielded benzoic and phenylacetic acids as transient intermediates, and these acids supported growth of the isolates.

  17. Enantioselective degradation and unidirectional chiral inversion of 2-phenylbutyric acid, an intermediate from linear alkylbenzene, by Xanthobacter flavus PA1

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yishan; Han, Ping [School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Li, Xiao-yan; Shih, Kaimin [Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong (China); Gu, Ji-Dong, E-mail: jdgu@hkucc.hku.hk [School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong (China); The Swire Institute of Marine Science, The University of Hong Kong, Shek O, Cape d' Aguilar, Hong Kong (China)

    2011-09-15

    Highlights: {yields} We isolated a Xanthobacter flavus strain PA1 utilizing the racemic 2-PBA and the single enantiomers as the sole source of carbon and energy. {yields} Both (R) and (S) forms of enantiomers can be degraded in a sequential manner in which the (S) disappeared before the (R) form. {yields} The biochemical degradation pathway involves an initial oxidation of the alkyl side chain before aromatic ring cleavage. - Abstract: Microbial degradation of the chiral 2-phenylbutyric acid (2-PBA), a metabolite of surfactant linear alkylbenzene sulfonates (LAS), was investigated using both racemic and enantiomer-pure compounds together with quantitative stereoselective analyses. A pure culture of bacteria, identified as Xanthobacter flavus strain PA1 isolated from the mangrove sediment of Hong Kong Mai Po Nature Reserve, was able to utilize the racemic 2-PBA as well as the single enantiomers as the sole source of carbon and energy. In the presence of the racemic compounds, X. flavus PA1 degraded both (R) and (S) forms of enantiomers to completion in a sequential manner in which the (S) enantiomer disappeared much faster than the (R) enantiomer. When the single pure enantiomer was supplied as the sole substrate, a unidirectional chiral inversion involving (S) enantiomer to (R) enantiomer was evident. No major difference was observed in the degradation intermediates with either of the individual enantiomers when used as the growth substrate. Two major degradation intermediates were detected and identified as 3-hydroxy-2-phenylbutanoic acid and 4-methyl-3-phenyloxetan-2-one, using a combination of liquid chromatography-mass spectrometry (LC-MS), and {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR) spectroscopy. The biochemical degradation pathway follows an initial oxidation of the alkyl side chain before aromatic ring cleavage. This study reveals new evidence for enantiomeric inversion catalyzed by pure culture of environmental bacteria and emphasizes the

  18. Las degradation in a fluidized bed reactor and phylogenetic characterization of the biofilm

    Directory of Open Access Journals (Sweden)

    L. L. Oliveira

    2013-09-01

    Full Text Available A fluidized bed reactor was used to study the degradation of the surfactant linear alkylbenzene sulfonate (LAS. The reactor was inoculated with anaerobic sludge and was fed with a synthetic substrate supplemented with LAS in increasing concentrations (8.2 to 45.8 mg l-1. The removal efficiency of 93% was obtained after 270 days of operation. Subsequently, 16S rRNA gene sequencing and phylogenetic analysis of the sample at the last stage of the reactor operation recovered 105 clones belonging to the domain Bacteria. These clones represented a variety of phyla with significant homology to Bacteroidetes (40%, Proteobacteria (42%, Verrucomicrobia (4%, Acidobacteria (3%, Firmicutes (2%, and Gemmatimonadetes (1%. A small fraction of the clones (8% was not related to any phylum. Such phyla variety indicated the role of microbial consortia in degrading the surfactant LAS.

  19. New biodegradable air-entraining admixture based on LAS for cement-based composites

    International Nuclear Information System (INIS)

    Mendes, J.C.; Moro, T.K.; Dias, L.S.; Campos, P.A.M.; Silva, G.J.B.; Peixoto, R.A.F.; Cury, A.A.

    2016-01-01

    The active principle of Air Entraining Admixtures (AEA) are surfactants, analogously to washing up liquids. Washing up (or dishwashing) liquids are widely available products, relatively inexpensive, non-toxic and biodegradable, thus presenting smaller environmental impact. Therefore, the present work proposes the use of a biodegradable surfactant comprised in washing up liquids, Linear Alkylbenzene Sulfonate (LAS), as sustainable air entraining agent for cement-based composites. In this sense, a performance evaluation of the proposed AEA is carried out, by comparing the properties of mortars with proposed AEA, commercial AEA and ones without any admixture. Through the physical, mechanical and microstructural analysis, it was possible to determine the efficiency of the proposed AEA, as well as its optimum range of dosage. As a result, we seek to contribute to the technical development of cement-based composites in Brazil and in the world. (author)

  20. Sulfonated methyl esters of fatty acids in aqueous solutions: Interfacial and micellar properties.

    Science.gov (United States)

    Danov, Krassimir D; Stanimirova, Rumyana D; Kralchevsky, Peter A; Basheva, Elka S; Ivanova, Veronika I; Petkov, Jordan T

    2015-11-01

    The interest to sulfonated methyl esters of fatty acids (SME) has been growing during the last decade, because these surfactants are considered as an environmentally friendly and renewable alternative of the linear alkyl-benzene sulfonates (LAS). Here, we present a quantitative study on the properties of aqueous SME solutions, and especially on their surface tension isotherms, critical micelle concentration (CMC) and its dependence on the concentration of added NaCl. It is demonstrated that the CMC of an ionic surfactant determined by electrical conductivity is insensitive to the presence of a small nonionic admixture, so that the CMC values determined by conductivity represent the CMC of the pure surfactant. Using SME as an example, we have demonstrated the application of a new and powerful method for determining the physicochemical parameters of the pure ionic surfactant by theoretical data analysis ("computer purification") if the used surfactant sample contains nonionic admixtures, which are present as a rule. This method involves fits of the experimental data for surface tension and conductivity by a physicochemical model based on a system of mass-balance, chemical-equilibrium and electric-double-layer equations, which allows us to determine the adsorption and micellization parameters of C12-, C14-, C16- and C18-SME, as well the fraction of nonionic admixtures (if any). Having determined these parameters, we can further predict the interfacial and micellization properties of the surfactant solutions, such as surface tension, adsorption, degree of counterion binding, and surface electric potential at every surfactant, salt and co-surfactant concentrations. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Densities, isobaric thermal expansion coefficients and isothermal compressibilities of linear alkylbenzene

    International Nuclear Information System (INIS)

    Zhou, X; Zhang, Z Y; Zhang, Q M; Liu, Q; Ding, Y Y; Zhou, L; Cao, J

    2015-01-01

    We report the measurements of the densities of linear alkylbenzene at three temperatures over 4 to 23 °C with pressures up to 10 MPa. The measurements have been analysed to yield the isobaric thermal expansion coefficients and, so far for the first time, isothermal compressibilities of linear alkylbenzene. Relevance of results for current generation (i.e., Daya Bay) and next generation (i.e. JUNO) large liquid scintillator neutrino detectors are discussed. (paper)

  2. Sulfonation and molecular action.

    Science.gov (United States)

    Strott, Charles A

    2002-10-01

    The sulfonation of endogenous molecules is a pervasive biological phenomenon that is not always easily understood, and although it is increasingly recognized as a function of fundamental importance, there remain areas in which significant cognizance is still lacking or at most minimal. This is particularly true in the field of endocrinology, in which the sulfoconjugation of hormones is a widespread occurrence that is only partially, if at all, appreciated. In the realm of steroid/sterol sulfoconjugation, the discovery of a novel gene that utilizes an alternative exon 1 to encode for two sulfotransferase isoforms, one of which sulfonates cholesterol and the other pregnenolone, has been an important advance. This is significant because cholesterol sulfate plays a crucial role in physiological systems such as keratinocyte differentiation and development of the skin barrier, and pregnenolone sulfate is now acknowledged as an important neurosteroid. The sulfonation of thyroglobulin and thyroid hormones has been extensively investigated and, although this transformation is better understood, there remain areas of incomplete comprehension. The sulfonation of catecholamines is a prevalent modification that has been extensively studied but, unfortunately, remains poorly understood. The sulfonation of pituitary glycoprotein hormones, especially LH and TSH, does not affect binding to their cognate receptors; however, sulfonation does play an important role in their plasma clearance, which indirectly has a significant effect on biological activity. On the other hand, the sulfonation of distinct neuroendocrine peptides does have a profound influence on receptor binding and, thus, a direct effect on biological activity. The sulfonation of specific extracellular structures plays an essential role in the binding and signaling of a large family of extracellular growth factors. In summary, sulfonation is a ubiquitous posttranslational modification of hormones and extracellular

  3. Geochemical significance of alkylbenzene distributions in flash pyrolysates of kerogens, coals and asphaltenes

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hartgers, W.A.; Leeuw, J.W. de

    1994-01-01

    The distribution of C0-C5 alkylbenzenes in flash pyrolysates of forty-seven immature kerogens and coals from different geographical locations and of different ages were studied using gas chromatography (GC) in combination with mass spectrometry (MS) in order to decipher the origin of aromatic

  4. Analytical methodology for sulfonated lignins

    NARCIS (Netherlands)

    Brudin, S.; Schoenmakers, P.

    2010-01-01

    There is a significant need to characterize and classify lignins and sulfonated lignins. Lignins have so far received a good deal of attention, whereas this is not true for sulfonated lignins. There is a clear demand for a better understanding of sulfonated lignins on a chemical as well as physical

  5. Synthesis of dodecyl lauroyl benzene sulfonate and its application in enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Zhenggang; Wu, Le; Sun, Mingming; Jiang, Jian-zhong; Wang, Feng [Jiangnan Univ., Wuxi (China). School of Chemical and Material Engineering

    2011-09-15

    A new hydrophobic surfactant, dodecyl lauroyl benzene sulfonate (DLBS), was synthesized and its application in enhanced oil recovery by alkali-surfactant-polymer (ASP) flooding was studied. The results show that DLBS can be synthesized by reaction of industrial dodecyl benzene with lauroyl chloride in the presence of AlCl{sub 3}, followed by sulfonation with ClSO{sub 3}H and neutralization with NaOH. The lauroyl-group is confirmed to be connected to the para-position of the alkylbenzene by1HNMR spectrum. The synthesized DLBS is well soluble in pure water and reservoir (connate) water at 45 C. It is highly surface active which is indicated by its low CMC of 1.1 . 10{sup -5} mol/L, and its low surface tension, {gamma}{sub cmc} of 28.6 mN m{sup -1}. By mixing with heavy alkylbenzene sulfonates of relatively low average molar mass (387g mol{sup -1}) at a total surfactant concentration of 5 mM, DLBS can reduce the interfacial tension of Daqing crude oil/connate water to an order of 10{sup -3} mN/m at 45 C in the presence of 0.5-1.0 wt.% NaOH and 1000 mg L{sup -1} of polymer. If the NaOH was replaced by a gentle alkaline salt, Na{sub 2}CO{sub 3}, certain amounts of dodecyl dimethyl carboxy betaine were added and the concentration of Na{sub 2}CO{sub 3} was increased to 1.2-2.0 wt.%, the interfacial tension of Daqing crude oil/connate water can also be reduced to an ultralow value. Therefore DLBS is a good hydrophobic surfactant applicable in ASP flooding with either NaOH or Na{sub 2}CO{sub 3} as alkaline agents. (orig.)

  6. Effect of Organic Loading Rates on biodegradation of linear alkyl benzene sulfonate, oil and grease in greywater by Integrated Fixed-film Activated Sludge (IFAS).

    Science.gov (United States)

    Eslami, Hadi; Ehrampoush, Mohammad Hassan; Ghaneian, Mohammad Taghi; Mokhtari, Mehdi; Ebrahimi, Aliasghar

    2017-05-15

    In this study, performance of Integrated Fixed-film Activated Sludge (IFAS) system in treatment of Linear Alkylbenzene Sulfonate (LAS), and oil & grease in synthetic greywater and effect of Organic Loading Rates (OLRs) on removal efficiency within a period of 105 days were investigated. Present study was carried out in a pilot scale under such conditions as temperature of 30 ± 1 °C, dissolved oxygen of 2.32 ± 0.91 mg/l, pH of 8.01 ± 0.95 and OLRs of 0.11-1.3gCOD/L.d. Also, Scanning Electron Microscopy (SEM) images were employed to specify rate of the biofilm formed on the media inside the reactor IFAS. The best removal efficiency for COD, LAS and oil and grease were respectively obtained as 92.52%, 94.24% and 90.07% in OLR 0.44gCOD/L.d. The assessment of loading rate indicated that with increased OLR to 0.44gCOD/L.d, removal efficiency of COD, oil and grease was increased while with increased OLR, removal efficiency was decreased. In doing so, based on the statistical test ANOVA, such a difference between removal efficiencies in diverse OLRs was significant for COD (p = 0.003), oil and grease (p = 0.01). However, in terms of LAS, with increased value of OLR to 0.44gCOD/L.d, the removal efficiency was increased and then with higher OLRs, removal efficiency was slightly decreased that is insignificant (p = 0.35) based on the statistical test ANOVA. The SEM images also showed that the biofilm formed on the media inside IFAS reactor plays a considerable role in adsorption and biodegradation of LAS, and oil & grease in greywater. The linear relation between inlet COD values and rate of removed LAS indicated that the ratio of inlet COD (mg/L) to removed LAS (mg/L) was 0.4. Therefore, use of IFAS system for biodegradation of LAS, oil and grease in greywater can be an applicable option. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC.

    Science.gov (United States)

    Jang, Hohyoun; Islam, Md Monirul; Lim, Youngdon; Hossain, Md Awlad; Cho, Younggil; Joo, Hyunho; Kim, Whangi; Jeon, Heung-Seok

    2014-10-01

    Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4'-(2,2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4, 4'-sulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211.

  8. Sulfonation in pharmacology and toxicology.

    Science.gov (United States)

    Kauffman, Frederick C

    2004-10-01

    Sulfonation has a major function in modulating the biological activities of a wide number of endogenous and foreign chemicals, including: drugs, toxic chemicals, hormones, and neurotransmitters. The activation as well as inactivation of many xenobiotics and endogenous compounds occurs via sulfonation. The process is catalyzed by members of the cytosolic sulfotransferase (SULT) superfamily consisting of at least ten functional genes in humans. The reaction in intact cells may be reversed by arylsulafatase present in the endoplasmic reticulum. Under physiological conditions, sulfonation is regulated, in part, by the supply of the co-substrate/donor molecule 3'-phosphadensoine-5-phosphosulfate (PAPS), and transport mechanisms by which sulfonated conjugates enter and leave cells. Variation in the response of individuals to certain drugs and toxic chemicals may be related to genetic polymorphisms documented to occur in each of the above pathways. Sulfonation has a major function in regulating the endocrine status of an individual by modulating the receptor activity of estrogens and androgens, steroid biosynthesis, and the metabolism of catecholamines and iodothyronines Sulfonation is a key reaction in the body's defense against injurious chemicals and may have a major function during early development since SULTs are highly expressed in the human fetus. As with many Phase I and Phase II reactions, sulfonation may also serve as the terminal step in activating certain dietary and environmental agents to very reactive toxic intermediates implicated in carcinogenesis.

  9. Photosynthesis tests as an alternative to growth tests for hazard assessment of toxicant

    DEFF Research Database (Denmark)

    Petersen, S.; Kusk, Kresten Ole

    2000-01-01

    Acute (3- and 6-h) toxic responses toward Cu, linear alkylbenzene sulfonate (LAS), and tributyltin (TBT) of lightsaturated and unsaturated photosynthesis were investigated for Rhodomonas salina and Skeletonema costatum obtained from exponentially growing batch cultures and from chemostat cultures...

  10. Preparation and characterization of proton exchange poly (ether sulfone)s membranes grafted propane sulfonic acid on pendant phenyl groups

    International Nuclear Information System (INIS)

    Lim, Youngdon; Seo, Dongwan; Hossain, Md. Awlad; Lee, Soonho; Lim, Jinseong; Jang, Hohyoun; Hong, Taehoon; Kim,; Kim, Whangi

    2014-01-01

    Poly(ether sulfone)s containing hexaphenyl (PHP) was prepared by 1,2-bis(4-hydroxyphenyl)-3,4,5,6-tetraphenylbenzene, 4,4-hydroxyphenylsulfone, and 4,4-fluorophenylsulfone, followed bromination on phenyl groups to produce brominated PHP (Br-PHP). Grafted sulfonated poly(ether sulfone)s containing hexaphenyl (GSPHP) were prepared from Br-PHP and 3-bromopropane sulfonic acid with potassium salt and copper powder. The salt form was converted to free acid using 1 M sulfuric acid solution. All these membranes were cast from dimethylacetamide (DMAc). The structural properties of the synthesized polymers were investigated by 1 H-NMR spectroscopy. The membranes were studied with regard to ion exchange capacity (IEC), water uptake, Fenton test, and proton conductivity. These grafted polymer membranes were compared with normal sulfonated poly(ether sulfone)s and Nafion

  11. Sulfonated polyphenyl ether by electropolymerization

    International Nuclear Information System (INIS)

    Hou Hongying; Vacandio, Florence; Di Vona, Maria Luisa; Knauth, Philippe

    2012-01-01

    Highlights: ► Sulfonated polyphenyl ether was for the first time electropolymerized. ► This technique allows the economical preparation of ionomeric membranes for electrochemical energy technologies. ► The mechanism of electropolymerization was discussed in detail. - Abstract: Electropolymerization of sulfonated phenol was for the first time achieved and studied by cyclic voltammetry (CV) and chronoamperometry on stainless steel substrates. The obtained sulfonated polyphenyl ether was characterized in terms of impedance spectroscopy, nuclear magnetic resonance (NMR), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and Fourier-Transform Infrared (FTIR) spectroscopy. Dense films of micrometer thickness can be obtained; the proton conductivity is about 3 mS/cm at room temperature.

  12. Lignin Sulfonation - A different Approach

    DEFF Research Database (Denmark)

    Bjørkmann, Anders

    2001-01-01

    . It was found that lignin is very reactive, that is why the sulfonation chemistry alone does not necessarily determine its dissolution rate. It became evident that the ultrastructure dispersion of lignin in wood is beneficial for its dissolution. For W, the rate was much higher at pH 1.5 than at 6. MW lignin...... and MWL dissolved (after extraction of the "immediate" lignin) at higher rates than W lignin. For MWL, the rate difference between pH 1.5 and 6 was moderate, compared to W lignin. Borohydride reduction did not affect the lignin dissolution from W, but gave a large decrease of sulfonation rate for MWL...

  13. Sulfonated polyaniline: influence of sulfonation routes on its thermal and structural characteristics

    OpenAIRE

    Mendes,Luis Claudio; Falco,Ana Paula Santiago; Pinho,Magali Silveira; Marques,Priscila Oliveira

    2011-01-01

    In order to study the influence of different sulfonation routes on its thermal and structural properties sulfonated polyaniline (SPAni) was prepared. FT-IR revealed that the formation of PAni salt or ring sulfonation depends on the route. UV-visible spectra pointed out that the level of the PAni protonation was dependent on the sulfonation route. A new approach was given for TG/DTG and DSC results correlating different energy levels with the distinguished sulfonation routes. The TG/DTG degrad...

  14. Safety assessment of xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes as used in cosmetics.

    Science.gov (United States)

    Bergfeld, Wilma F; Belsito, Donald V; Klaassen, Curtis D; Hill, Ronald; Liebler, Daniel; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2011-12-01

    Xylene sulfonic acid, toluene sulfonic acid, and alkyl aryl sulfonate hydrotropes used in cosmetics as surfactants, hydrotropes, were reviewed in this safety assessment. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. The Cosmetic Ingredient Review Expert Panel reviewed relevant animal and human data related to these ingredients. The panel concluded that xylene sulfonic acid and alkyl aryl sulfonate hydrotropes are safe as cosmetic ingredients in the present practices of use and concentrations as described in this safety assessment, when formulated to be nonirritating.

  15. Synthesis and characterization of sulfonated cardo poly(arylene ether sulfone)s for fuel cell proton exchange membrane application

    Energy Technology Data Exchange (ETDEWEB)

    Islam, M.M.; Jang, H.H.; Lim, Y.D.; Seo, D.W.; Kim, W.G. [Department of Applied Chemistry, Konkuk University, Chungju, Chungbuk (Korea, Republic of); Kim, T.H.; Hong, Y.T. [Energy Material Research Center, Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Kim, D.M. [Material Engineering and Science, Hongik Univ, Jochiwon-eup, Yeongi-gun, Chungnam (Korea, Republic of)

    2012-12-15

    Sulfonated cardo poly(arylene ether sulfone)s (SPPA-PES) with various degrees of sulfonation (DS) were prepared by post-sulfonation of synthesized phenolphthalein anilide (PPA; N-phenyl-3,3'-bis(4-hydroxyphenyl)-1-isobenzopyrolidone) poly(arylene ether sulfone)s (PPA-PES) by using concentrated sulfuric acid. PPA-PES copolymers were synthesized by direct polycondensation of PPA with bis-(4-fluorophenyl)-sulfone and 4,4'-sulfonyldiphenol. The DS was varied with different mole ratios of PPA (24, 30, 40, 50 mol.%) in the polymer. The structure of the resulting SPPA-PES copolymers and the different contents of the sulfonated unit were studied by Fourier transform infrared (FT-IR) spectroscopy, {sup 1}H NMR spectroscopy, and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity of SPPA-PES were evaluated according to the increase of DS. The water uptake (WU) of the resulting SPPA-PES membranes was in the range of 20-72%, compared with 28% for Nafion 211 registered. The SPPA-PES membranes showed proton conductivities of 23-82 mS cm{sup -1}, compared with 194 mS cm{sup -1} for Nafion 211 registered, under 100% relative humidity (RH) at 80 C. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. A durable alternative for proton-exchange membranes: sulfonated poly(benzoxazole thioether sulfone)s

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dan [Center for Innovative Fuel Cell and Battery Technologies, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Lab of PEMFC Key Materials and Technologies, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Liaoning, Dalian 116023 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Li, Jinhuan [Center for Innovative Fuel Cell and Battery Technologies, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Song, Min-Kyu; Liu, Meilin [Center for Innovative Fuel Cell and Battery Technologies, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Yi, Baolian; Zhang, Huamin [Lab of PEMFC Key Materials and Technologies, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Liaoning, Dalian 116023 (China)

    2011-03-18

    To develop a durable proton-exchange membrane (PEM) for fuel-cell applications, a series of sulfonated poly(benzoxazole thioether sulfone)s (SPTESBOs) are designed and synthesized, with anticipated good dimensional stability (via acid-base cross linking), improved oxidative stability against free radicals (via incorporation of thioether groups), and enhanced inherent stability (via elimination of unstable end groups) of the backbone. The structures and the degree of sulfonation of the copolymers are characterized using Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy ({sup 1}H NMR and {sup 19}F NMR). The electrochemical stabilities of the monomers are examined using cyclic voltammetry in a typical three-electrode cell configuration. The physicochemical properties of the membranes vital to fuel-cell performance are also carefully evaluated under conditions relevant to fuel-cell operation, including chemical and thermal stability, proton conductivity, solubility in different solvents, water uptake, and swelling ratio. The new membranes exhibit low dimensional change at 25 C to 90 C and excellent thermal stability up to 250 C. Upon elimination of unstable end groups, the co-polymers display enhanced chemical resistance and oxidative stability in Fenton's test. Further, the SPTESBO-HFB-60 (HFB-60=hexafluorobenzene, 60 mol% sulfone) membrane displays comparable fuel-cell performance to that of an NRE 212 membrane at 80 C under fully humidified condition, suggesting that the new membranes have the potential to be more durable but less expensive for fuel-cell applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. A Durable Alternative for Proton-Exchange Membranes: Sulfonated Poly(Benzoxazole Thioether Sulfone)s

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dan; Li, Jin Hui; Song, Min Kyu; Yi, Baolian; Zhang, Huamin; Liu, Meilin

    2011-02-24

    To develop a durable proton-exchange membrane (PEM) for fuel-cell applications, a series of sulfonated poly(benzoxazole thioether sulfone)s ( SPTESBOs) are designed and synthesized, with anticipated good dimensional stability (via acid–base cross linking), improved oxidative stability against free radicals (via incorporation of thioether groups), and enhanced inherent stability (via elimination of unstable end groups) of the backbone. The structures and the degree of sulfonation of the copolymers are characterized using Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy ({sup 1}H NMR and {sup 19}F NMR). The electrochemical stabilities of the monomers are examined using cyclic voltammetry in a typical three-electrode cell configuration. The physicochemical properties of the membranes vital to fuel-cell performance are also carefully evaluated under conditions relevant to fuel-cell operation, including chemical and thermal stability, proton conductivity, solubility in different solvents, water uptake, and swelling ratio. The new membranes exhibit low dimensional change at 25°C to 90°C and excellent thermal stability up to 250°C. Upon elimination of unstable end groups, the co-polymers display enhanced chemical resistance and oxidative stability in Fenton's test. Further, the SPTESBO-HFB-60 (HFB-60=hexafluorobenzene, 60 mol% sulfone) membrane displays comparable fuel-cell performance to that of an NRE 212 membrane at 80°C under fully humidified condition, suggesting that the new membranes have the potential to be more durable but less expensive for fuel-cell applications.

  18. Cation permeable membranes from blends of sulfonated poly(ether ether ketone) and poly (ether sulfone)

    NARCIS (Netherlands)

    Wilhelm, F.G.; Punt, Ineke G.M.; van der Vegt, N.F.A.; Strathmann, H.; Wessling, Matthias

    2002-01-01

    Sulfonated poly(aryl ether ether ketone), S-PEEK, is blended with non-sulfonated poly(ether sulfone) (PES) to adjust the properties of ion permeable and ion selective membranes. In this study, membranes are prepared from blends with (i) a S-PEEK content between 10 and 100 wt.% using one S-PEEK batch

  19. Benzyltributylammonium 7-hydroxynaphthalene-1-sulfonate

    Directory of Open Access Journals (Sweden)

    Jin Mizuguchi

    2009-02-01

    Full Text Available The title compound, C19H34N+·C10H7O4S−, is a charge-control agent used for toners in electrophotography. The anions form one-dimensional chains by O—H...O hydrogen bonds in a zigzag fashion along the c axis between the OH group of one anion and the sulfonate O atom of a neighboring anion. One of the n-butyl chains of the cation is disordered over two sites in a 0.77:0.23 ratio.

  20. Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads

    Directory of Open Access Journals (Sweden)

    Igor Rocha

    2018-03-01

    Full Text Available Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels, coagulation activation (thrombin-antithrombin (TAT levels and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

  1. Blood Compatibility of Sulfonated Cladophora Nanocellulose Beads.

    Science.gov (United States)

    Rocha, Igor; Lindh, Jonas; Hong, Jaan; Strømme, Maria; Mihranyan, Albert; Ferraz, Natalia

    2018-03-07

    Sulfonated cellulose beads were prepared by oxidation of Cladophora nanocellulose to 2,3-dialdehyde cellulose followed by sulfonation using bisulfite. The physicochemical properties of the sulfonated beads, i.e., high surface area, high degree of oxidation, spherical shape, and the possibility of tailoring the porosity, make them interesting candidates for the development of immunosorbent platforms, including their application in extracorporeal blood treatments. A desired property for materials used in such applications is blood compatibility; therefore in the present work, we investigate the hemocompatibility of the sulfonated cellulose beads using an in vitro whole blood model. Complement system activation (C3a and sC5b-9 levels), coagulation activation (thrombin-antithrombin (TAT) levels) and hemolysis were evaluated after whole blood contact with the sulfonated beads and the results were compared with the values obtained with the unmodified Cladophora nanocellulose. Results showed that neither of the cellulosic materials presented hemolytic activity. A marked decrease in TAT levels was observed after blood contact with the sulfonated beads, compared with Cladophora nanocellulose. However, the chemical modification did not promote an improvement in Cladophora nanocellulose hemocompatibility in terms of complement system activation. Even though the sulfonated beads presented a significant reduction in pro-coagulant activity compared with the unmodified material, further modification strategies need to be investigated to control the complement activation by the cellulosic materials.

  2. Extreme ultraviolet (EUV) degradation of poly(olefin sulfone)s: Towards applications as EUV photoresists

    International Nuclear Information System (INIS)

    Lawrie, Kirsten; Blakey, Idriss; Blinco, James; Gronheid, Roel; Jack, Kevin; Pollentier, Ivan; Leeson, Michael J.; Younkin, Todd R.; Whittaker, Andrew K.

    2011-01-01

    Poly(olefin sulfone)s, formed by the reaction of sulfur dioxide (SO 2 ) and an olefin, are known to be highly susceptible to degradation by radiation and thus have been identified as candidate materials for chain scission-based extreme ultraviolet lithography (EUVL) resist materials. In order to investigate this further, the synthesis and characterisation of two poly(olefin sulfone)s namely poly(1-pentene sulfone) (PPS) and poly(2-methyl-1-pentene sulfone) (PMPS), was achieved and the two materials were evaluated for possible chain scission EUVL resist applications. It was found that both materials possess high sensitivities to EUV photons; however; the rates of outgassing were extremely high. The only observed degradation products were found to be SO 2 and the respective olefin suggesting that depolymerisation takes place under irradiation in a vacuum environment. In addition to depolymerisation, a concurrent conversion of SO 2 moieties to a sulfide phase was observed using XPS.

  3. Sulfonated polyaniline: influence of sulfonation routes on its thermal and structural characteristics

    Directory of Open Access Journals (Sweden)

    Luis Claudio Mendes

    2011-12-01

    Full Text Available In order to study the influence of different sulfonation routes on its thermal and structural properties sulfonated polyaniline (SPAni was prepared. FT-IR revealed that the formation of PAni salt or ring sulfonation depends on the route. UV-visible spectra pointed out that the level of the PAni protonation was dependent on the sulfonation route. A new approach was given for TG/DTG and DSC results correlating different energy levels with the distinguished sulfonation routes. The TG/DTG degradation steps and the amount of the released material corroborated the structural differences of the polyanilines. For each DSC first regime of heating, a broad and intense peak (from -30 to 250 ºC with different level of energy was noticed. That peak could be ascribed to the multiple relaxations and breaking of the PAni intra and inter hydrogen bonds after sulfonation.

  4. Chlorine resistant desalination membranes based on directly sulfonated poly(arylene ether sulfone) copolymers

    Science.gov (United States)

    McGrath, James E [Blacksburg, VA; Park, Ho Bum [Austin, TX; Freeman, Benny D [Austin, TX

    2011-10-04

    The present invention provides a membrane, kit, and method of making a hydrophilic-hydrophobic random copolymer membrane. The hydrophilic-hydrophobic random copolymer membrane includes a hydrophilic-hydrophobic random copolymer. The hydrophilic-hydrophobic random copolymer includes one or more hydrophilic monomers having a sulfonated polyarylsulfone monomer and a second monomer and one or more hydrophobic monomers having a non-sulfonated third monomer and a fourth monomer. The sulfonated polyarylsulfone monomer introduces a sulfonate into the hydrophilic-hydrophobic random copolymer prior to polymerization.

  5. Enhancement of proton conductivity of sulfonated polystyrene ...

    Indian Academy of Sciences (India)

    Enhancement of proton conductivity of sulfonated polystyrene membrane prepared by plasma polymerization process. BHABESH KUMAR NATH, AZIZ KHAN, JOYANTI CHUTIA. ∗. , ARUP RATAN PAL,. HEREMBA BAILUNG, NEELOTPAL SEN SARMA, DEVASISH CHOWDHURY and NIRAB CHANDRA ADHIKARY.

  6. Direct catalytic olefination of alcohols with sulfones.

    Science.gov (United States)

    Srimani, Dipankar; Leitus, Gregory; Ben-David, Yehoshoa; Milstein, David

    2014-10-06

    The synthesis of terminal, as well as internal, olefins was achieved by the one-step olefination of alcohols with sulfones catalyzed by a ruthenium pincer complex. Furthermore, performing the reaction with dimethyl sulfone under mild hydrogen pressure provides a direct route for the replacement of alcohol hydroxy groups by methyl groups in one step. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Sulfonation of vulcanized ethylene-propylene-diene terpolymer membranes

    International Nuclear Information System (INIS)

    Barroso-Bujans, F.; Verdejo, R.; Lozano, A.; Fierro, J.L.G.; Lopez-Manchado, M.A.

    2008-01-01

    In the present work, sulfonation of previously vulcanized ethylene propylene diene terpolymer (EPDM) membranes was developed in a swelling solvent with acetyl sulfate. This procedure avoids the need to pre-dissolve the raw polymer. The reaction conditions were optimized in terms of solvent type, reaction time, acetyl sulfate concentration and film thickness to obtain the maximum degree of sulfonation of the polymer. The sulfonation procedure presented in this study yields a degree of sulfonation comparable to the chlorosulfonic acid procedure. Sulfonic acid groups were detected by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and quantified by titrations. Proton conductivity and water uptake were measured by means of impedance spectroscopy and swelling measurements, respectively, and were correlated with the degree of sulfonation. Tensile strength and Young's modulus of sulfonated EPDM increased with the degree of sulfonation, while elongation at break remained constant. Thermal stability of the sulfonated EPDM was studied by simultaneous thermogravimetry-mass spectroscopy

  8. Effects of gamma radiation from 60Co on dilute aqueous solutions of Linear Alkyl Sulfonate Surfactants and other organic pollutants

    International Nuclear Information System (INIS)

    Rohrer, D.M.

    1975-01-01

    This study is the result of research findings and operational experiences gained by the author in over four years of work associated with the use of 60 Co for the treatment of waste-water. The effects of 60 Co are discussed with regard to radiochemical destruction of specific organic pollutant species. The study deals specifically with the effects of gamma radiation from a 30,000 Ci 60 Co source upon aqueous solutions of Linear Alkyl Sulfonate Surfactants. The new Linear Alkyl Sulfonate (LAS) Surfactants, the major surfactant produced in the United States of America since June 1965, was developed to replace the old Alkyl Benzene Sulfonate (ABS) Surfactants. The reason for the removal of Alkyl Benzene Sulfonate Surfactants was their extreme environmental stability and the associated appearance of foam in waste-water treatment plants and receiving streams. Although the Linear Alkyl Sulfonate Surfactants are considered 'bio-degradable', the time required for 'bio-degradation' is impractical within the present environmental guidelines. This led to research into alternate techniques of treatment for the destruction of Linear Alkyl Sulfonate Surfactants. Consideration is also given to similar effects of gamma radiation upon pesticides and to the practical aspects of the use of gamma radiation for the treatment of waste-water. Included are discussions of the general experimental procedures used, the sources and their calibration, and sampling techniques to ensure the accuracy of the data. (author)

  9. Anaerobic biodegradation of alkylbenzenes and trichloroethylene in aquifer sediment down gradient of a sanitary landfill

    Science.gov (United States)

    Johnston, James J.; Borden, Robert C.; Barlaz, Morton A.

    1996-08-01

    The objective of this investigation was to evaluate the anaerobic biodegradability of benzene, toluene, ethylbenzene, ortho-, meta- and para-xylene (BTEX) and trichloroethylene (TCE) in aquifer sediment down gradient of an unlined landfill. The major organic contaminants identified in the shallow unconfined aquifer are cis-dichloroethylene ( c-DCE) and toluene. The biodegradative potential of the contaminated aquifer was measured in three sets of microcosms constructed using anaerobic aquifer sediment from three boreholes down gradient of the landfill. The degradability of BTEX and TCE was examined under ambient and amended conditions. TCE was degraded in microcosms with aquifer material from all three boreholes. Toluene biodegradation was inconsistent, exhibiting biodegradation with no lag in one set of microcosms but more limited biodegradation in two additional sets of microcosms. TCE exhibited an inhibitory effect on toluene degradation at one location. The addition of calcium carbonate stimulated TCE biodegradation which was not further stimulated by nutrient addition. TCE was converted to ethylene, a harmless byproduct, in all tests. Benzene, ethylbenzene and xylene isomers were recalcitrant in both ambient and amendment experiments. Biodegradation occurred under methanogenic conditions as methane was produced in all experiments. Bromoethane sulfonic acid (BES), a methanogenic inhibitor, inhibited methane and ethylene production and TCE biodegradation. The results indicate the potential for intrinsic bioremediation of TCE and toluene down gradient of the Wilder's Grove, North Carolina, landfill. The low concentrations of TCE in monitoring wells was consistent with its biodegradation in laboratory microcosms.

  10. Tetrahydrobiopterin regulates monoamine neurotransmitter sulfonation.

    Science.gov (United States)

    Cook, Ian; Wang, Ting; Leyh, Thomas S

    2017-07-03

    Monoamine neurotransmitters are among the hundreds of signaling small molecules whose target interactions are switched "on" and "off" via transfer of the sulfuryl-moiety (-SO 3 ) from PAPS (3'-phosphoadenosine 5'-phosphosulfate) to the hydroxyls and amines of their scaffolds. These transfer reactions are catalyzed by a small family of broad-specificity enzymes-the human cytosolic sulfotransferases (SULTs). The first structure of a SULT allosteric-binding site (that of SULT1A1) has recently come to light. The site is conserved among SULT1 family members and is promiscuous-it binds catechins, a naturally occurring family of flavanols. Here, the catechin-binding site of SULT1A3, which sulfonates monoamine neurotransmitters, is modeled on that of 1A1 and used to screen in silico for endogenous metabolite 1A3 allosteres. Screening predicted a single high-affinity allostere, tetrahydrobiopterin (THB), an essential cofactor in monoamine neurotransmitter biosynthesis. THB is shown to bind and inhibit SULT1A3 with high affinity, 23 (±2) nM, and to bind weakly, if at all, to the four other major SULTs found in brain and liver. The structure of the THB-bound binding site is determined and confirms that THB binds the catechin site. A structural comparison of SULT1A3 with SULT1A1 (its immediate evolutionary progenitor) reveals how SULT1A3 acquired high affinity for THB and that the majority of residue changes needed to transform 1A1 into 1A3 are clustered at the allosteric and active sites. Finally, sequence records reveal that the coevolution of these sites played an essential role in the evolution of simian neurotransmitter metabolism.

  11. Response of resident bacteria in a tropical detergent effluent ...

    African Journals Online (AJOL)

    Bacteria were isolated from a tropical detergent-polluted stream, and their responses to linear alkylbenzene sulfonate (LAS) were investigated. The responses of the resident bacteria were assessed in terms of their ability or failure to grow in the presence of LAS and of their potential to degrade the surfactant. Eighteen ...

  12. Sulfonated graphenes catalyzed synthesis of expanded porphyrins ...

    Indian Academy of Sciences (India)

    Sulfonated graphene; expanded porphyrins; heterogeneous catalysis; solid acid; non-covalent interaction. 1. Introduction. Graphene, an important allotropic member of carbon, has received much attention owing to its interest- ing properties in material science with wide range of applications in energy devices, electronics, ...

  13. Fate and biodegradability of sulfonated aromatic amines

    NARCIS (Netherlands)

    Tan, N.C.G.; Leeuwen, van A.; Voorthuizen, van E.M.; Slenders, P.; Prenafeta, F.X.; Temmink, H.; Lettinga, G.; Field, J.A.

    2005-01-01

    Ten sulfonated aromatic amines were tested for their aerobic and anaerobic biodegradability and toxicity potential in a variety of environmental inocula. Of all the compounds tested, only two aminobenzenesulfonic acid (ABS) isomers, 2- and 4-ABS, were degraded. The observed degradation occurred only

  14. Enhancement of proton conductivity of sulfonated polystyrene ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 37; Issue 7. Enhancement of proton conductivity of sulfonated polystyrene membrane prepared by plasma polymerization process. Bhabesh Kumar Nath Aziz Khan Joyanti Chutia Arup Ratan Pal Heremba Bailung Neelotpal Sen Sarma Devasish Chowdhury Nirab ...

  15. Sulfonated graphenes catalyzed synthesis of expanded porphyrins ...

    Indian Academy of Sciences (India)

    A newer synthesis of sulfonic acid functionalized graphenes have been developed, which have been characterized, examined as heterogeneous solid acid carbocatalyst in the synthesis of selected expanded porphyrins in different reaction conditions. This environment-friendly catalyst avoids the use of toxic catalysts and ...

  16. Room temperature synthesis of biodiesel using sulfonated ...

    Science.gov (United States)

    Sulfonation of graphitic carbon nitride (g-CN) affords a polar and strongly acidic catalyst, Sg-CN, which displays unprecedented reactivity and selectivity in biodiesel synthesis and esterification reactions at room temperature. Prepared for submission to Royal Society of Chemistry (RSC) journal, Green Chemistry as a communication.

  17. Enhancement of proton conductivity of sulfonated polystyrene

    Indian Academy of Sciences (India)

    This work reports the achievement of higher proton conductivity of polystyrene based proton exchange membrane synthesized in a continuous RF plasma polymerization process using two precursors, styrene (C8H8) and trifluoromethane sulfonic acid (CF3SO3H). The chemical composition of the developed membranes is ...

  18. Enhancement of proton conductivity of sulfonated polystyrene ...

    Indian Academy of Sciences (India)

    like proton transport, water uptake, sulfonation rate, ion exchange capacity and thermal behaviour. The proton conductivity of the ... Plasma polymerization process; ion exchange capacity; proton conductivity; thermal stability. 1. Introduction ... of low proton conductivity at operating temperature greater than 100. ◦. C due to ...

  19. Carbon dioxide sensing with sulfonated polyaniline

    NARCIS (Netherlands)

    Doan, D.C.T.; Ramaneti, R.; Baggerman, J.; Bent, van der J.; Marcelis, A.T.M.; Tong, H.D.; Rijn, van C.J.M.

    2012-01-01

    The use of polyaniline and especially sulfonated polyaniline (SPAN) is explored for sensing carbon dioxide (CO2) at room temperature. Frequency-dependent AC measurements were carried out to detect changes in impedance of the polymer, drop casted on interdigitated electrodes, when exposed to CO2 gas.

  20. Sulindac Sulfide, but Not Sulindac Sulfone, Inhibits Colorectal Cancer Growth

    Directory of Open Access Journals (Sweden)

    Christopher S. Williams

    1999-06-01

    Full Text Available Sulindac sulfide, a metabolite of the nonsteroidal antiinflammatory drug (NSAID sulindac sulfoxide, is effective at reducing tumor burden in both familial adenomatous polyposis patients and in animals with colorectal cancer. Another sulindac sulfoxide metabolite, sulindac sulfone, has been reported to have antitumor properties without inhibiting cyclooxygenase activity. Here we report the effect of sulindac sulfone treatment on the growth of colorectal carcinoma cells. We observed that sulindac sulfide or sulfone treatment of HCA-7 cells led to inhibition of prostaglandin E2 production. Both sulindac sulfide and sulfone inhibited HCA-7 and HCT-116 cell growth in vitro. Sulindac sulfone had no effect on the growth of either HCA-7 or HCT-116 xenografts, whereas the sulfide derivative inhibited HCA-7 growth in vivo. Both sulindac sulfide and sulfone inhibited colon carcinoma cell growth and prostaglandin production in vitro, but sulindac sulfone had no effect on the growth of colon cancer cell xenografts in nude mice.

  1. Tracing sewage pollution using linear alkylbenzenes (LABs) in surface sediments at the south end of the Southern California Bight

    International Nuclear Information System (INIS)

    Macias-Zamora, J.V.; Ramirez-Alvarez, N.

    2004-01-01

    Distribution and isomeric composition of LABs in surface marine sediments were evaluated at the southern end of the southern California Bight. LABs are used as tracers of wastewater discharges. The area studied extends from the Mexico-USA border to the Todos Santos Bay, Baja California in the south. The area was partitioned into a northern, central and a southern stratum. GC-MS was used for the analysis of LABs concentration. The average value of total LABs concentration was 17.4, 32.0 and 24.9 ng/g for the north, central and southern strata, respectively. LABs were not correlated with either sediments grain size (% 10 , LAB 11 ) showed enrichment. It was found that 67 out of the 68 stations measured had concentrations above detection limits. This suggests extensive contact of wastewater discharges with marine sediments in the area. An estimate of the amount of LABs per year based on detergent consumption per capita is provided. - Linear alkylbenzenes were used to trace the distribution of sewage pollution of surface marine sediments

  2. Effect of sulfonation degree on molecular weight, thermal stability, and proton conductivity of poly(arylene ether sulfone)s membrane.

    Science.gov (United States)

    Pirali-Hamedani, Majid; Mehdipour-Ataei, Shahram

    2017-01-01

    Direct copolymerization of sulfonated and non-sulfonated difluorodiphenyl sulfones as dihalide monomers with hydroquinone and also 4,4'-(4,4'-sulfonylbis-(1,4-phenylene)bis(oxy)) diphenol as diols led to preparation of two series of poly(arylene ether sulfone)s. Copolymers with different degrees of sulfonation (40, 50 and 60%) were synthesized in order to evaluate their potential for fuel cell application. 1 H-NMR, FT-IR, and mass spectroscopy were used for characterization of prepared monomers and copolymers. Differential scanning calorimetry and thermogravimetric analysis were applied for investigation and comparison of the thermal properties of copolymers. Laser light scattering (LLS) was employed to calculate zeta potential, conductivity, and molecular weight of copolymers. Copolymers were obtained in high and sufficient molecular weight that was basic need to reach reasonable physical and thermal properties for applications as fuel cell membrane. The effect of similar structural repeating units with different sizes on the final properties of sulfonated poly(ether sulfone)s was investigated to compare their potential in fuel cell membrane.

  3. Ferrocene sulfonates as electrocatalysts for sulfide detection

    International Nuclear Information System (INIS)

    Lawrence, Nathan S.; Tustin, Gary J.; Faulkner, Michael; Jones, Timothy G.J.

    2006-01-01

    The electrochemical characterization of both the mono- and di-substituted forms of ferrocene sulfonate are given. The results show both species produce voltammograms consistent with quasi-irreversible diffusion controlled redox reactions. The FcSO 3 - species was found to be easier to oxidize than its Fc(SO 3 ) 2 2- counterpart, due to the electron withdrawing affect of the sulfonate group on the Fe centre. In the presence of sulfide, the voltammetric response of FcSO 3 - is shown to be consistent with the occurrence of an electrocatalytic EC' reaction. This analytical response was utilized as a means of determining sulfide and was found to be linear over the concentration 0.02-1 mM with a limit of detection of 14 μM

  4. Synthesis and characterization of sulfonated polyesters derived from glycerol

    International Nuclear Information System (INIS)

    Fiuza, R.A.; Jose, N.M.; Boaventura, J.S.; Fiuza, R.P.

    2010-01-01

    In this work were synthesized polyesters from glycerol and acid sulfonated phthalic previously. The materials were characterized by DSC, TGA, FTIR, SEM, XRD and XRF. The results showed effective sulfonation of phthalic acid. The presence of sulfonic groups promoted strong changes in the crystallinity of the new material makes the lens. The polyesters made from phthalic acid sulfonated combine characteristics such as heat resistance and groups that drivers potentiate the electrolyte for application in fuel cells proton exchange membrane and also for gas separation. (author)

  5. Detection, quantifications and pharmacokinetics of toltrazuril sulfone (Ponazuril) in cattle.

    Science.gov (United States)

    Dirikolu, L; Yohn, R; Garrett, E F; Chakkath, T; Ferguson, D C

    2009-06-01

    Toltrazuril sulfone (Ponazuril) is a triazine-based anti-protozoal agent with highly specific actions against apicomplexan group of organisms, which are undergoing intensive investigation. Toltrazuril sulfone may have clinical application in the treatment of Neospora. caninum and other protozoal infections in cattle. To evaluate absorption, distribution, and elimination characteristics of toltrazuril sulfone in cattle, a sensitive validated quantitative high-pressure liquid chromatography method for toltrazuril sulfone in bovine biological fluids was developed. After a single oral dose of toltrazuril sulfone at 5 mg/kg (as 150 mg/g of Marquis; Bayer HealthCare, Shawnee Mission, KS, USA), samples from six cows showed good plasma concentrations of toltrazuril sulfone, which peaked at 4821 ng/mL +/- 916 (SD) at 48 h postadministration. Thereafter, plasma concentration declined to 1950 ng/mL +/- 184 (SD) at 192 h after administration with an average plasma elimination half-life of approximately 58 h. Following oral dose of toltrazuril sulfone, the observed peak plasma concentrations were in relatively close agreement ranging from the lowest 3925 ng/mL to the highest of 6285 ng/mL with the mean peak plasma concentration being 4821 ng/mL. This study shows that toltrazuril sulfone is relatively well absorbed after oral dose in cattle. These results are therefore entirely consistent with and support the reported clinical efficacy of toltrazuril sulfone in the treatment of experimentally induced clinical cases of N. caninum and other protozoal-mediated bovine diseases.

  6. Comparing sensitivity of ecotoxicological effect endpoints between laboratory and field

    DEFF Research Database (Denmark)

    Selck, H.; Riemann, B.; Christoffersen, K.

    2002-01-01

    multispecies field tests using tributyltin (TBT) and linear alkylbenzene sulfonates (LAS) were compared with published laboratory single-species test results and measured in situ concentrations. Extrapolation methods were evaluated by comparing predicted no-effect concentrations (PNECs), calculated by AF...

  7. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    OpenAIRE

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing sulfonated units were prepared by blending styrene-block-butadiene-block-styrene (SBS), with both sulfonated PS and sulfonated SEBS in a Brabender mixer. Such a procedure was performed as an alter...

  8. Thermal and Dielectric Behavior Studies of Poly(Arylene Ether Sulfones with Sulfonated and Phosphonated Pendants

    Directory of Open Access Journals (Sweden)

    Shimoga D. Ganesh

    2016-01-01

    Full Text Available The present paper discusses the aspects of the synthesizing valeric acid based poly(ether sulfones with active carboxylic acid pendants (VALPSU from solution polymerization technique via nucleophilic displacement polycondensation reaction among 4,4′-dichlorodiphenyl sulfone (DCDPS and 4,4′-bis(4-hydroxyphenyl valeric acid (BHPA. The conditions necessary to synthesize and purify the polymer were investigated in some detail. The synthesized poly(ether sulfones comprise sulfone and ether linkages in addition to reactive carboxylic acid functionality; these active carboxylic acid functional groups were exploited to hold the phenyl sulphonic acid and phenyl phosphonic acid pendants. The phenyl sulphonic acid pendants in VALPSU were easily constructed by altering active carboxylic acid moieties by sulfanilic acid using N,N′-dicyclohexylcarbodiimide (DCC mediated mild synthetic route, whereas the latter one was built in two steps. Initially, polyphosphoric acid condensation with VALPSU by 4-bromoaniline and next straightforward palladium catalyzed synthetic route, in both of which acidic pendants are clenched by polymer backbone via amide linkage. Without impairing the primary polymeric backbone modified polymers were prepared by varying the stoichiometric ratios of respective combinations. All the polymers were physicochemically characterized and pressed into tablets; electrical contacts were established to study the dielectric properties. Finally, the influence of the acidic pendants on the dielectric properties was examined.

  9. Synthesis of Sulfonated burdock fructooligosaccharide (BFO)

    Science.gov (United States)

    Zhang, Haiguang; Chen, Kaoshan; Zhang, Pengying; Zhang, Xian; Wang, Zhe; Xue, Jingwen

    2017-12-01

    Burdock Fructooligosaccharide (BFO) were sulfated using SO3-Py complex. The maximal degree of sulfonation (DSsulf) was 1.56, which were obtained by varying reaction factor such molar ratio of SO3-Py to fructofuranans unit (FU). The FT-IR, 1H NMR and 13C NMR spectra showed the introduction of sulfate group, and the reaction occurred at C-6, C-4 and C-3 in the fructofuranans unit of BFO. The molecular weight estimated by HPGPC were 6104.7-11003.3 g/mol for S-BFO (DS sulf=1.2).

  10. Fate of linear alkylbenzenes and benzothiazoles of anthropogenic origin and their potential as environmental molecular markers in the Pearl River Delta, South China

    International Nuclear Information System (INIS)

    Ni Honggang; Shen Rulang; Zeng Hui; Zeng, Eddy Y.

    2009-01-01

    The mass emissions of linear alkylbenzenes (LABs), benzothiazole (BT), and 2-[4-morpholinyl]benzothiazole (24MoBT) from anthropogenic activities within one year were estimated according to the population and the number of automobiles in the Pearl River Delta (PRD), South China. Based on the estimation, the distribution of these compounds among various environmental media was simulated with a mass balance box model established in the present study. The results showed that 79% of LABs generated in the PRD was stored in sediment while only 1.3% of LABs was presumably transported to the adjacent South China Sea (SCS). On the contrary, 47% of BT and 77% of 24MoBT generated in the region were carried with riverine runoff to the coastal ocean. The results from the present study suggest that hydrophobic compounds tend to stay in the watershed of the PRD, whereas hydrophilic ones mainly outflow to the coastal ocean. - A simple mass balance box model examines the fate of linear alkylbenzenes and benzothiazoles in the Pearl River Delta, South China.

  11. A cut-off in ocular chemesthesis from vapors of homologous alkylbenzenes and 2-ketones as revealed by concentration-detection functions

    International Nuclear Information System (INIS)

    Cometto-Muniz, J. Enrique; Abraham, Michael H.

    2008-01-01

    Studies of homologous series of environmental vapors have shown that their chemesthetic (i.e., sensory irritation) potency increases with carbon chain length (that is, their detection thresholds decrease) until they reach a homolog that fails to be detected, even at vapor saturation. All ensuing homologs cannot be detected either. In this investigation, we measured concentration-detection (i.e., psychometric) functions for ocular chemesthesis from homologous alkylbenzenes (pentyl, hexyl, and heptyl benzene) and 2-ketones (undecanone, dodecanone, and tridecanone). Using a three-alternative forced-choice procedure against air blanks, we tested a total of 18 to 24 subjects, about half of them females, average age 31 years, ranging from 18 to 56 years. Stimuli were generated and presented by a computer-controlled, vapor delivery device whose output was quantified by gas chromatography. Exposure time was 6 s and delivery flow 2.5 L/min. Within the context of present and previous findings, the outcome indicated that the functions for heptylbenzene and 2-tridecanone reached a plateau where further increases in concentration did not enhance detection. We conclude that: a) a cut-off point in ocular chemesthetic detection is reached along homologous alkylbenzenes and 2-ketones at the level of heptylbenzene and 2-tridecanone, respectively, and b) the observed effect rests on the homologs exceeding a critical molecular size (or dimension) rather than on them failing to achieve a high enough vapor concentration

  12. Optimization of gas chromatography using short glass capillary column with mass spectrometry for identification and evaluation of commercial heavy alkylbenzene structures.

    Science.gov (United States)

    Ghoreishi, S M; Beiggy, M; Mazloum Ardekani, M

    2003-04-01

    Heavy alkylbenzene (HAB) is one of the by-products when producing linear alkylbenzene (LAB). Identification of the fine structures of HAB is difficult because of its complex structure and high boiling point. The gas chromatography/mass spectrometry (GC/MS) technique with a short glass capillary column is the best method applicable to analysis of high-boiling and thermally labile compounds. The column efficiency is evaluated on the basis of Van Deemter curves. The experimental results show that the reduction in the optimum column efficiency for a short glass capillary column occurs along with a reduction in effective theoretical plates. A second important result is that the shift in the value of the flow velocity is related to the optimum point in height equivalent theoretical plate (HETP). The flow velocity is higher than that of conventional gas chromatography(GC). The optimized conditions were used to analyse HAB produced through the hydrogen fluoride (HF) alkylation process. The results show acceptable relative separation of a product in an extended boiling point range. The optimized conditions were also used to analyse three other special samples supplied by BASF company's AlCl(3 )alkylation process and to approve the previous structures. The results also show that HAB from Iran Chemical Industries Investment Company (ICIIC) produced through LAB complex consists of an additional part and has more linearity than the other three samples of HAB obtained from BASF.

  13. Polyether sulfone membrane modeling and construction for the ...

    African Journals Online (AJOL)

    Polyether sulfone membrane modeling and construction for the removal of nitrate from water using ion interference sulfate and iron nano-particle. ... The aim of this study was constructed the polyether sulfone membrane and modelling it, and for checking impact pressure, the amount of iron nanoparticles and sulfate iron ...

  14. Sulfonated carbon black-based composite membranes for fuel cell

    Indian Academy of Sciences (India)

    Composite membranes were then prepared using S–C as fillers and sulfonated poly(ether ether ketone) (SPEEK) as polymer matrix with three different sulfonation degrees (DS = 60, 70 and 82%). Structure and properties of the composite membranes were characterized by FTIR, TGA, scanning electron microscopy, proton ...

  15. Preparation and Characterization of Sulfonated Poly (ether ether ...

    African Journals Online (AJOL)

    Proton-conducting membranes of organic–inorganic (sulfonated poly (ether ether ketone)/phosphated zirconia nanoparticles) composite were prepared by incorporating various ratios of phosphated zirconia nanoparticles (ZP) in sulfonated poly (ether ether ketone) (SPEEK). SPEEK/ZP showed an improvement of ...

  16. Convenient Regioselective mono-2-O-Sulfonation of Cyclomaltooctaose.

    Science.gov (United States)

    Teranishi, K; Tanabe, S; Hisamatsu, M; Yamada, T

    1998-01-01

    Regioselective mono-2-O-sulfonation of cyclomaltooctaose was conveniently achieved by using the combination of sulfonyl imidazole and molecular sieves in DMF. In this reaction, no 3-O- or 6-O-sulfonation products were produced. The reactions do not require strict anhydrous or basic conditions, or specific sulfonyl groups.

  17. Bisphenol A sulfonation is impaired in metabolic and liver disease.

    Science.gov (United States)

    Yalcin, Emine B; Kulkarni, Supriya R; Slitt, Angela L; King, Roberta

    2016-02-01

    Bisphenol A (BPA) is a widely used industrial chemical and suspected endocrine disruptor to which humans are ubiquitously exposed. The liver metabolizes and facilitates BPA excretion through glucuronidation and sulfonation. The sulfotransferase enzymes contributing to BPA sulfonation (detected in human and rodents) is poorly understood. To determine the impact of metabolic and liver disease on BPA sulfonation in human and mouse livers. The capacity for BPA sulfonation was determined in human liver samples that were categorized into different stages of metabolic and liver disease (including obesity, diabetes, steatosis, and cirrhosis) and in livers from ob/ob mice. In human liver tissues, BPA sulfonation was substantially lower in livers from subjects with steatosis (23%), diabetes cirrhosis (16%), and cirrhosis (18%), relative to healthy individuals with non-fatty livers (100%). In livers of obese mice (ob/ob), BPA sulfonation was lower (23%) than in livers from lean wild-type controls (100%). In addition to BPA sulfonation activity, Sult1a1 protein expression decreased by 97% in obese mouse livers. Taken together these findings establish a profoundly reduced capacity of BPA elimination via sulfonation in obese or diabetic individuals and in those with fatty or cirrhotic livers versus individuals with healthy livers. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Sulfonation of alkyl phenyl ether self-assembled monolayers.

    Science.gov (United States)

    Katash, Irit; Luo, Xianglin; Sukenik, Chaim N

    2010-02-02

    The sulfonation of phenyl ether decorated self-assembled monolayers (SAMs) was studied with an eye toward creating surfaces with a particularly high negative charge density based on a close-packed array of phenyl rings with more than one sulfonic acid group per molecule. The product distribution and kinetics of this process were studied by ultraviolet, infrared, and photoelectron spectroscopies and by monitoring changes in the thickness and wetting properties of the SAM. The sulfonation chemistry could be effected without undermining monolayer integrity and the isomer distribution of ortho- and para-monosulfonated material, along with the percentages of mono- and disulfonated molecules could be established throughout the process. As doubly sulfonated molecules appeared, the reaction slowed drastically. Ultimately, sulfonation stops completely with approximately 60% of the molecules disulfonated and 20% each of the two monosulfonated isomers. This striking constraint on monolayer reactivity and the relationship between the surface chemistry and variations in SAM structure are discussed.

  19. Bisphenol A sulfonation is impaired in metabolic and liver disease

    International Nuclear Information System (INIS)

    Yalcin, Emine B.; Kulkarni, Supriya R.; Slitt, Angela L.; King, Roberta

    2016-01-01

    Background: Bisphenol A (BPA) is a widely used industrial chemical and suspected endocrine disruptor to which humans are ubiquitously exposed. The liver metabolizes and facilitates BPA excretion through glucuronidation and sulfonation. The sulfotransferase enzymes contributing to BPA sulfonation (detected in human and rodents) is poorly understood. Objectives: To determine the impact of metabolic and liver disease on BPA sulfonation in human and mouse livers. Methods: The capacity for BPA sulfonation was determined in human liver samples that were categorized into different stages of metabolic and liver disease (including obesity, diabetes, steatosis, and cirrhosis) and in livers from ob/ob mice. Results: In human liver tissues, BPA sulfonation was substantially lower in livers from subjects with steatosis (23%), diabetes cirrhosis (16%), and cirrhosis (18%), relative to healthy individuals with non-fatty livers (100%). In livers of obese mice (ob/ob), BPA sulfonation was lower (23%) than in livers from lean wild-type controls (100%). In addition to BPA sulfonation activity, Sult1a1 protein expression decreased by 97% in obese mouse livers. Conclusion: Taken together these findings establish a profoundly reduced capacity of BPA elimination via sulfonation in obese or diabetic individuals and in those with fatty or cirrhotic livers versus individuals with healthy livers. - Highlights: • Present study demonstrates that hepatic SULT 1A1/1A3 are primarily sulfonate BPA in mouse and human. • Hepatic BPA sulfonation is profoundly reduced steatosis, diabetes and cirrhosis. • With BPA-S detectable in urine under low or common exposures, these findings are novel and important.

  20. Chitin nanowhisker-supported sulfonated poly(ether sulfone) proton exchange for fuel cell applications.

    Science.gov (United States)

    Zhang, Chan; Zhuang, Xupin; Li, Xiaojie; Wang, Wei; Cheng, Bowen; Kang, Weimin; Cai, Zhanjun; Li, Mengqin

    2016-04-20

    To balance the relationship among proton conductivity and mechanic strength of sulfonated poly(ether sulfone) (SPES) membrane, chitin nanowhisker-supported nanocomposite membranes were prepared by incorporating whiskers into SPES. The as-prepared chitin whiskers were prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) mediated oxidation of α-chitin from crab shells. The structure and properties of the composite membranes were examined as proton exchange membrane (PEM). Results showed that chitin nanowhiskers were dispersed incompactly in the SPES matrix. Thermal stability, mechanical properties, water uptake and proton conductivity of the nanocomposite films were improved from those of the pure SPES film with increasing whisker content, which ascribed to strong interactions between whiskers and between SPES molecules and chitin whiskers via hydrogen bonding. These indicated that composition of filler and matrix got good properties and whisker-supported membranes are promising materials for PEM. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Preparation of new proton exchange membranes using sulfonated poly(ether sulfone) modified by octylamine (SPESOS)

    International Nuclear Information System (INIS)

    Mabrouk, W.; Ogier, L.; Matoussi, F.; Sollogoub, C.; Vidal, S.; Dachraoui, M.; Fauvarque, J.F.

    2011-01-01

    Highlights: → New, simple and cheap way to synthesize a membrane. → The membranes combine good proton conductivities with good mechanical properties. → The membrane performances in a fuel cell are similar to the Nafion 117. - Abstract: Sulfonated poly(arylene ether sulfone) (SPES) has received considerable attention in membrane preparation for proton exchange membrane fuel cell (PEMFC). But such membranes are brittle and difficult to handle in operation. We investigated new membranes using SPES grafted with various degrees of octylamine. Five new materials made from sulfonated polyethersulfone sulfonamide (SPESOS) were synthetized with different grades of grafting. They were made from SPES, with initially an ionic exchange capacity (IEC) of 2.4 meq g -1 (1.3 H + per monomer unit). Pristine SPES with that IEC is water swelling and becomes soluble at 80 deg. C, its proton conductivity is in the range of 0.1 S cm -1 at room temperature in aqueous H 2 SO 4 1 M, similar to that of Nafion. After grafting with various amounts of octylamine, the material is water insoluble; membranes are less brittle and show sufficient ionic conductivity. Proton transport numbers were measured close to 1.

  2. Electrical conductivity of sulfonated poly(ether ether ketone) based composite membranes containing sulfonated polyhedral oligosilsesquioxane

    Science.gov (United States)

    Celso, Fabricio; Mikhailenko, Serguei D.; Rodrigues, Marco A. S.; Mauler, Raquel S.; Kaliaguine, Serge

    2016-02-01

    Composite proton exchange membranes (PEMs) intended for fuel cell applications were prepared by embedding of various amounts of dispersed tri-sulfonic acid ethyl POSS (S-Et-POSS) and tri-sulfonic acid butyl POSS (S-Bu-POSS) in thin films of sulfonated poly ether-ether ketone. The electrical properties of the PEMs were studied by Impedance spectroscopy and it was found that their conductivity σ changes with the filler content following a curve with a maximum. The water uptake of these PEMs showed the same dependence. The investigation of initial isolated S-POSS substances revealed the properties of typical electrolytes, which however in both cases possessed low conductivities of 1. 17 × 10-5 S cm-1 (S-Et-POSS) and 3.52 × 10-5 S cm-1 (S-Bu-POSS). At the same time, the insoluble in water S-POSS was found forming highly conductive interface layer when wetted with liquid water and hence producing a strong positive impact on the conductivity of the composite PEM. Electrical properties of the composites were analysed within the frameworks of effective medium theory and bounding models, allowing to evaluate analytically the range of possible conductivity values. It was found that these approaches produced quite good approximation of the experimental data and constituted a fair basis for interpretation of the observed relationship.

  3. 4-(4-Aminophenylsulfonylanilinium toluene-4-sulfonate

    Directory of Open Access Journals (Sweden)

    Graham Smith

    2014-01-01

    Full Text Available In the title p-toluenesulfonate salt of the drug dapsone, C12H13N2O2S+·C7H7O3S−, the dihedral angle between the two aromatic rings of the dapsone monocation is 70.19 (17° and those between these rings and that of the p-toluenesulfonate anion are 72.34 (17 and 46.43 (17°. All amine and aminium H atoms are involved in intermolecular N—H...O hydrogen-bonding associations with sulfonyl O-atom acceptors as well as one of the sulfone O atoms, giving a three-dimensional structure.

  4. Boiling significantly promotes photodegradation of perfluorooctane sulfonate.

    Science.gov (United States)

    Lyu, Xian-Jin; Li, Wen-Wei; Lam, Paul K S; Yu, Han-Qing

    2015-11-01

    The application of photochemical processes for perfluorooctane sulfonate (PFOS) degradation has been limited by a low treatment efficiency. This study reports a significant acceleration of PFOS photodegradation under boiling condition compared with the non-boiling control. The PFOS decomposition rate increased with the increasing boiling intensity, but declined at a higher hydronium level or under oxygenation. These results suggest that the boiling state of solution resulted in higher effective concentrations of reactants at the gas-liquid interface and enhanced the interfacial mass transfer, thereby accelerating the PFOS decomposition. This study broadens our knowledge of PFOS photodegradation process and may have implications for development of efficient photodegradation technologies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Fully Aromatic Block Copolymers for Fuel Cell Membranes with Densely Sulfonated Nanophase Domains

    DEFF Research Database (Denmark)

    Takamuku, Shogo; Jannasch, Patrick; Lund, Peter Brilner

    Two multiblock copoly(arylene ether sulfone)s with similar block lengths and ion exchange capacities (IECs) were prepared by a coupling reaction between a non-sulfonated precursor block and a highly sulfonated precursor block containing either fully disulfonated diarylsulfone or fully...... tetrasulfonated tetraaryldisulfone segments. The latter two precursor blocks were sulfonated via lithiation-sulfination reactions whereby the sulfonic acid groups were exclu- sively placed in ortho positions to the many sulfone bridges, giving these locks IECs of 4.1 and 4.6 meqg1, respectively. Copolymer...

  6. Propagation/depropagation equilibrium and structural factors in the radiation degradation of poly(olefin sulfone)s

    International Nuclear Information System (INIS)

    Bowmer, T.N.; O'Donnell, J.H.

    1981-01-01

    The principal volatile products observed after γ irradiation of nine different poly(olefin sulfone)s in the solid state were the two comonomers, i.e., the respective olefin and sulfur dioxide. An exponential increase in yield, G (volatile products), with increasing irradiation temperature, T/sub irr/, was observed for each copolymer through the ceiling temperature, T/sub c/, for the corresponding propagation/depropagation equilibrium. Thus the G value increased by ca. 3 orders of magnitude from T/sub irr/ = 0.7 T/sub c/ to T/sub irr/ = 1.3 T/sub c/ for all of the poly(olefin sulfone)s. Depropagation sensitivity was considered to be best measured by G(SO 2 ) since radiation induced, cationic homopolymerization of the product olefin occurred to a variable extent. Five of the poly(olefin sulfone)s had similar rates of depropagation at their respective T/sub c's/ but the polysulfones of 1-hexene, cyclohexene and 2-butene showed anomalously high depropagation rates. This may be related to greater steric hinderance to segmental chain mobility in the polysulfones of the 1,2 disubstituted olefins. Poly(1-hexene sulfone) appears to be anomalous, as in other respects

  7. Sulfonated hydrocarbon graft architectures for cation exchange membranes

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    A synthetic strategy to hydrocarbon graft architectures prepared from a commercial polysulfone and aimed as ion exchange membrane material is proposed. Polystyrene is grafted from a polysulfone macroinitiator by atom transfer radical polymerization, and subsequently sulfonated with acetyl sulfate...

  8. Room temperature synthesis of biodiesel using sulfonated graphitic carbon nitride

    OpenAIRE

    Baig, R. B. Nasir; Verma, Sanny; Nadagouda, Mallikarjuna N.; Varma, Rajender S.

    2016-01-01

    Sulfonation of graphitic carbon nitride (g-CN) affords a polar and strongly acidic catalyst, Sg-CN, which displays unprecedented reactivity and selectivity in biodiesel synthesis and esterification reactions at room temperature.

  9. Room temperature synthesis of biodiesel using sulfonated graphitic carbon nitride

    Science.gov (United States)

    Sulfonation of graphitic carbon nitride (g-CN) affords a polar and strongly acidic catalyst, Sg-CN, which displays unprecedented reactivity and selectivity in biodiesel synthesis and esterification reactions at room temperature.

  10. Cyclic Tetrapyrrole Sulfonation, Metals, and Oligomerization in Antiprion Activity▿

    Science.gov (United States)

    Caughey, Winslow S.; Priola, Suzette A.; Kocisko, David A.; Raymond, Lynne D.; Ward, Anne; Caughey, Byron

    2007-01-01

    Cyclic tetrapyrroles are among the most potent compounds with activity against transmissible spongiform encephalopathies (TSEs; or prion diseases). Here the effects of differential sulfonation and metal binding to cyclic tetrapyrroles were investigated. Their potencies in inhibiting disease-associated protease-resistant prion protein were compared in several types of TSE-infected cell cultures. In addition, prophylactic antiscrapie activities were determined in scrapie-infected mice. The activity of phthalocyanine was relatively insensitive to the number of peripheral sulfonate groups but varied with the type of metal bound at the center of the molecule. The tendency of the various phthalocyanine sulfonates to oligomerize (i.e., stack) correlated with anti-TSE activity. Notably, aluminum(III) phthalocyanine tetrasulfonate was both the poorest anti-TSE compound and the least prone to oligomerization in aqueous media. Similar comparisons of iron- and manganese-bound porphyrin sulfonates confirmed that stacking ability correlates with anti-TSE activity among cyclic tetrapyrroles. PMID:17709470

  11. Cyclic tetrapyrrole sulfonation, metals, and oligomerization in antiprion activity.

    Science.gov (United States)

    Caughey, Winslow S; Priola, Suzette A; Kocisko, David A; Raymond, Lynne D; Ward, Anne; Caughey, Byron

    2007-11-01

    Cyclic tetrapyrroles are among the most potent compounds with activity against transmissible spongiform encephalopathies (TSEs; or prion diseases). Here the effects of differential sulfonation and metal binding to cyclic tetrapyrroles were investigated. Their potencies in inhibiting disease-associated protease-resistant prion protein were compared in several types of TSE-infected cell cultures. In addition, prophylactic antiscrapie activities were determined in scrapie-infected mice. The activity of phthalocyanine was relatively insensitive to the number of peripheral sulfonate groups but varied with the type of metal bound at the center of the molecule. The tendency of the various phthalocyanine sulfonates to oligomerize (i.e., stack) correlated with anti-TSE activity. Notably, aluminum(III) phthalocyanine tetrasulfonate was both the poorest anti-TSE compound and the least prone to oligomerization in aqueous media. Similar comparisons of iron- and manganese-bound porphyrin sulfonates confirmed that stacking ability correlates with anti-TSE activity among cyclic tetrapyrroles.

  12. Oil recovery with vinyl sulfonic acid-acrylamide copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1973-12-18

    An aqueous polymer flood containing sulfomethylated alkali metal vinyl sulfonate-acrylamide copolymers was proposed for use in secondary or tertiary enhanced oil recovery. The sulfonate groups on the copolymers sustain the viscosity of the flood in the presence of brine and lime. Injection of the copolymer solution into a waterflooded Berea core, produced 30.5 percent of the residual oil. It is preferred that the copolymers are partially hydrolyzed.

  13. The case of sulfonation in the chemical synthesis of oligonucleotides.

    OpenAIRE

    Kraszewski, A; Stawiński, J; Wiewiórowski, M

    1980-01-01

    The sulfonation of nucleosidic component, a side reaction during phosphotriester bond formation, as a function of the reactivity of the condensing agents and the kind of substituents in the starting phosphodiester is discussed. It was found that in the coupling reaction of nucleoside alkyl phosphodiesters, the degree of sulfonation of the nucleosidic component was very high; while under the same conditions when the aryl group was present in the corresponding phosphodiester, this side reaction...

  14. The case of sulfonation in the chemical synthesis of oligonucleotides.

    Science.gov (United States)

    Kraszewski, A; Stawiński, J; Wiewiórowski, M

    1980-01-01

    The sulfonation of nucleosidic component, a side reaction during phosphotriester bond formation, as a function of the reactivity of the condensing agents and the kind of substituents in the starting phosphodiester is discussed. It was found that in the coupling reaction of nucleoside alkyl phosphodiesters, the degree of sulfonation of the nucleosidic component was very high; while under the same conditions when the aryl group was present in the corresponding phosphodiester, this side reaction practically did not occur. PMID:6253882

  15. Characterization of a Sulfonated Polycarbonate Resistive Humidity Sensor

    Directory of Open Access Journals (Sweden)

    Claudio L. Donnici

    2013-02-01

    Full Text Available In this work; resistive moisture sensors were obtained by dip coating sulfonated polycarbonate (SPC onto silver interdigitated electrodes. Commercial polycarbonate was sulfonated with acetyl sulphate at two different sulfonation degrees corresponding to 9.0 and 18.0 mole %. Impedance spectroscopy was used to investigate the humidity sensing properties at controlled relative humidity (RH% environments generated from standard saline solutions in the range of 11–90 RH%. For the highest sulfonated sample; in the RH% range investigated (11 to 90%; the sensor impedance changed from 4.7 MΩ to 18 kΩ. Humidity sensors made from sulfonated polycarbonate showed exponential decay behavior of the impedance at constant frequency with the environmental relative humidity. Sample 9SPC presented dielectric relaxation response for environmental humidity between 58 and 90 RH% while sample 18SPC presented dielectric relaxation response for the entire measured range between 11 and 90 RH%. Sulfonated polycarbonate could be a promising material for the fabrication of simple and cheap humidity-sensing sensors for the assessment of relative humidity of the surrounding environment, as suggested by experimental results.

  16. Sulfonation of curcuminoids: characterization and contribution of individual SULT enzymes.

    Science.gov (United States)

    Lu, Xiaoyue; Jiang, Kunyu; Han, Long; Zhang, Maofan; Zhou, Yu; Ma, Yinglin; Zhou, Yiping; Meng, Shengnan

    2015-04-01

    Poor oral bioavailability of curcuminoids limited their various applications, and one of the main reasons is their rapid metabolism in vivo. Sulfonation via sulfotransferases (SULTs) is an important metabolic pathway for such compounds. The objective of this study is to determine the SULT-isoform-specific metabolic fingerprint, tissue-specific rate, and reaction kinetic profiles to describe the characterization and contribution of curcuminoids sulfonation. Sulfonation of curcuminoids was investigated by using nine expressed SULT isoforms and four pooled human tissue S9 fractions. The results showed that human small intestine is the predominant tissue responsible for sulfonation of curcuminoids. SULT1A3 is a major isoform catalyzing sulfonation of curcumin and demethoxycurcumin, but not for bisdemethoxycurcumin. SULT1B1 is only responsible for sulfonation of curcumin. Although SULT1C4 and 1E1 could highly catalyze the sulfate conjugations toward all the three compounds, the correlativities with human small intestine S9 fractions were much weaker (R(2) = 0.100-0.482). Almost all the kinetic profiles of the SULT isoforms for curcuminoids exhibited substrate inhibition kinetics. This investigation contributed to elucidate the SULT-mediated metabolism and detoxication of curcuminoids at molecular levels and in different organs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Celecoxib affects estrogen sulfonation catalyzed by several human hepatic sulfotransferases, but does not stimulate 17-sulfonation in rat liver.

    Science.gov (United States)

    Ambadapadi, Sriram; Wang, Peter L; Palii, Sergiu P; James, Margaret O

    2017-09-01

    Celecoxib is known to alter the preferred position of SULT2A1-catalyzed sulfonation of 17β-estradiol (17β-E2) and other estrogens from the 3- to the 17-position. Understanding the effects of celecoxib on estrogen sulfonation is of interest in the context of the investigational use of celecoxib to treat breast cancer. This study examined the effects on celecoxib on cytosolic sulfotransferases in human and rat liver and on SULT enzymes known to be expressed in liver. Celecoxib's effects on the sulfonation of several steroids catalyzed by human liver cytosol were similar but not identical to those observed previously for SULT2A1. Celecoxib was shown to inhibit recombinant SULT1A1-catalyzed sulfonation of 10nM estrone and 4μM p-nitrophenol with IC 50 values of 2.6 and 2.1μM, respectively, but did not inhibit SULT1E1-catalyzed estrone sulfonation. In human liver cytosol, the combined effect of celecoxib and known SULT1A1 and 1E1 inhibitors, quercetin and triclosan, resulted in inhibition of 17β-E2-3-sulfonation such that the 17-sulfate became the major metabolite: this is of interest because the 17-sulfate is not readily hydrolyzed by steroid sulfatase to 17β-E2. Investigation of hepatic cytosolic steroid sulfonation in rat revealed that celecoxib did not stimulate 17β-E2 17-sulfonation in male or female rat liver as it does with human SULT2A1 and human liver cytosol, demonstrating that rat is not a useful model of this effect. In silico studies suggested that the presence of the bulky tryptophan residue in the substrate-binding site of the rat SULT2A homolog instead of glycine as in human SULT2A1 may explain this species difference. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Multiblock copolymers with highly sulfonated blocks containing di- and tetrasulfonated arylene sulfone segments for proton exchange membrane fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Takamuku, Shogo; Jannasch, Patric [Polymer and Materials Chemistry, Department of Chemistry, Lund University (Sweden)

    2012-01-15

    Multiblock copoly(arylene ether sulfone)s with different block lengths and ionic contents are tailored for durable and proton-conducting electrolyte membranes. Two series of fully aromatic copolymers are prepared by coupling reactions between non-sulfonated hydrophobic precursor blocks and highly sulfonated hydrophilic precursor blocks containing either fully disulfonated diarylsulfone or fully tetrasulfonated tetraaryldisulfone segments. The sulfonic acid groups are exclusively introduced in ortho positions to the sulfone bridges to impede desulfonation reactions and give the blocks ion exchange capacities (IECs) of 4.1 and 4.6 meq. g{sup -1}, respectively. Solvent cast block copolymer membranes show well-connected hydrophilic nanophase domains for proton transport and high decomposition temperatures above 310 C under air. Despite higher IEC values, membranes containing tetrasulfonated tetraaryldisulfone segments display a markedly lower water uptake than the corresponding ones with disulfonated diarylsulfone segments when immersed in water at 100 C, presumably because of the much higher chain stiffness and glass transition temperature of the former segments. The former membranes have proton conductivities in level of a perfluorosulfonic acid membrane (NRE212) under fully humidified conditions. A membrane with an IEC of 1.83 meq. g{sup -1} reaches above 6 mS cm{sup -1} under 30% relative humidity at 80 C, to be compared with 10 mS cm{sup -1} for NRE212 under the same conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Controlled sulfonation of poly(ether sulfone using phthalic anhydride as catalyst and its membrane performance for fuel cell application

    Directory of Open Access Journals (Sweden)

    Seikh Jiyaur Rahaman

    2016-09-01

    Full Text Available Proton exchange membrane (PEM fuel cells are one of the most emerging alternative energy technologies under development. A novel proton exchange membrane sulfonated polyethersulfone (SPES was developed by homogeneous method using phthalic anhydride as catalyst and chlorosulfonic acid as sulfonating agent to control the sulfonation reaction. The method of sulfonation was optimized by varying the reaction time and concentration of the catalyst. The structure of the SPES was studied by 1H-Nuclear Magnetic Resonance, Fourier Transform Infra Red Spectroscopy and X-ray diffraction. The extent of sulfonation was determined by ion exchange capacity studies. The thermal and mechanical stabilities were studied using thermogravimetric analysis (TGA and Dynamic Mechanical Analysis (DMA respectively. DMA results show that the storage modulus increased with increase in degree of sulfonation (DS and water uptake of SPES increased with DS. The proton conductivity of SPES (34% DS measured by impedance spectroscopy was found to be 0.03S/cm at 80%RH and 100°C. Also, current-voltage polarization characteristics of SPES membranes offer a favourable alternative PEM due to the thermal stability and cost effective than perfluorinated ionomers.

  20. Benzyltributylammonium 6,7-dihydroxynaphthalene-2-sulfonate

    Directory of Open Access Journals (Sweden)

    Jin Mizuguchi

    2009-02-01

    Full Text Available The title molecular salt, C19H34N+·C10H7O5S−, is a charge-control agent used for toners in electrophotography. There are two formula units in the asymmetric unit. Both anions form inversion dimers connected by pairs of O—H...O hydrogen bonds between the –OH group of one anion and a sulfonic O atom of the neighboring one. The two dimers A and B are characterized by a step between the least-squares planes of the naphthalene atoms of 0.85 and 2.30 Å. Further O—H...O bonds link the dimers into a two-dimensional network propagating in (110 such that dimer A is hydrogen-bonded to four B units and vice versa. One of the tert-butyl chains in one of the cations is disordered over two sets of sites in a 0.56:0.44 ratio.

  1. Ion Exchange Formation via Sulfonated Bicomponent Nonwovens

    Science.gov (United States)

    Stoughton, Hannah L.

    For many years ion exchange resins were used to: remove heavy metals from water, recover materials from wastewater, and eliminate harmful gases from the air. While use of these resin beads dominates the ion exchange industry, the beads have limitations that should be considered when decisions are made to employ them. For instance, officials must balance the inherent zero sum surface area and porosity of the materials. This series of studies investigates the use of bicomponent nonwovens as a base substrate for producing high surface area ion exchange materials for the removal of heavy metal ions. Functionalized materials were produced in a two-step process: (1) PET/PE spunbond bicomponent fibers were fractured completely, producing the high surface area nonwoven to be used as the base ion exchange material, and (2) the conditions for functionalizing the PET fibers of the nonwoven webs were investigated where an epoxy containing monomer was grafted to the surface followed by sulfonation of the monomer. The functionalization reactions of the PET fibers were monitored based on: weight gain, FTIR, TOF-SIMS, and SEM. Ion exchange properties were evaluated using titration and copper ion removal capacity from test solutions. The relationship between web structure and removal efficiency of the metal ions was defined through a comparison of the bicomponent and homocomponent nonwovens for copper ion removal efficiency. The investigation revealed that utilizing the high surface area, fractured bicomponent nonwoven ion exchange materials with capacities comparable to commercially available ion exchange resins could be produced.

  2. Synthesis in pilot plant scale and physical properties of sulfonated polystyrene

    Directory of Open Access Journals (Sweden)

    Martins Cristiane R.

    2003-01-01

    Full Text Available The homogenous sulfonation of polystyrene was developed in a pilot plant scale producing polymers with different sulfonation degrees (18 to 22 mole % of sulfonated styrene units. The reaction yield depends chiefly on the concentration ratio of acetyl sulfate and polystyrene. The morphological and thermal properties of the sulfonated polystyrene obtained by homogeneous sulfonation were studied by means of scanning electron microscopy, differential scanning calorimetry and thermogravimetry. The glass transition temperature of sulfonated polystyrene increases in relation to pure polystyrene and DCp was evaluated in order to confirm the strong interactions among the ~SO3H groups.

  3. Perfluoroalkyl sulfonates cause alkyl chain length-dependent hepatic steatosis and hypolipidemia mainly by impairing lipoprotein production in APOE*3-leiden CETP mice

    NARCIS (Netherlands)

    Bijland, S.; Rensen, P.C.N.; Pieterman, E.J.; Maas, A.C.E.; Hoorn, J.W. van der; Erk, M.J. van; Havekes, L.M.; Dijk, K.W. van; Chang, S.C.; Ehresman, D.J.; Butenhoff, J.L.; Princen, H.M.G.

    2011-01-01

    Perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), and perfluorooctane sulfonate (PFOS) are stable perfluoroalkyl sulfonate (PFAS) surfactants, and PFHxS and PFOS are frequently detected in human biomonitoring studies. Some epidemiological studies have shown modest positive

  4. Sulfonation of environmental estrogens by zebrafish cytosolic sulfotransferases.

    Science.gov (United States)

    Ohkimoto, Kei; Sugahara, Takuya; Sakakibara, Yoichi; Suiko, Masahito; Liu, Ming-Yih; Carter, Glendora; Liu, Ming-Cheh

    2003-09-12

    Environmental estrogen-like chemicals are increasingly recognized as a potential hazardous factor for wildlife as well as humans. We have recently embarked on developing a zebrafish model for investigating the role of sulfonation in the metabolism and adverse functioning of environmental estrogens. Here, we report on a systematic investigation of the sulfonation of representative environmental estrogens (bisphenol A, 4-n-octylphenol, 4-n-nolylphenol, diethylstilbestrol, and 17 alpha-ethynylestradiol) by zebrafish cytosolic sulfotransferases (STs). Of the seven enzymes tested, four zebrafish STs (designated ZF ST #2, ZF ST #3, ZF ST #4, and ZF DHEA ST) exhibited differential sulfonating activities toward the five environmental estrogens tested, with ZF ST #3 being more highly active than the other three. It was further demonstrated that bisphenol A, 4-n-octylphenol, and 4-n-nonylphenol exerted concentration-dependent inhibition of the sulfonation of 17 beta-estradiol, implying a potential role of these environmental estrogens in interfering with the sulfonation, and possibly homeostasis, of endogenous estrogens. Kinetic studies revealed that the mechanism underlying the inhibition by bisphenol A or 4-n-nonylphenol to be of the competitive type.

  5. Synthesis and Properties of Poly(ether sulfone)s with Clustered Sulfonic Groups for PEMFC Applications under Various Relative Humidity.

    Science.gov (United States)

    Lee, Shih-Wei; Chen, Jyh-Chien; Wu, Jin-An; Chen, Kuei-Hsien

    2017-03-22

    Novel sulfonated poly(ether sulfone) copolymers (S4PH-x-PSs) based on a new aromatic diol containing four phenyl substituents at the 2, 2', 6, and 6' positions of 4,4'-diphenyl ether were synthesized. Sulfonation was found to occur exclusively on the 4 position of phenyl substituents by NMR spectroscopy. The ion exchange capacity (IEC) values can be controlled by adjusting the mole percent (x in S4PH-x-PS) of the new diol. The fully hydrated sulfonated poly(ether sulfone) copolymers had good proton conductivity in the range 0.004-0.110 S/cm at room temperature. The surface morphology of S4PH-x-PSs and Nafion 212 was investigated by atomic force microscopy (tapping-mode) and related to the percolation limit and proton conductivity. Single H 2 /O 2 fuel cell based on S4PH-40-PS loaded with 0.25 mg/cm 2 catalyst (Pt/C) exhibited a peak power density of 462.6 mW/cm 2 , which was close to that of Nafion 212 (533.5 mW/cm 2 ) at 80 °C with 80% RH. Furthermore, fuel cell performance of S4PH-35-PS with various relative humidity was investigated. It was confirmed from polarization curves that the fuel cell performance of S4PH-35-PS was not as high as that of Nafion 212 under fully hydrated state due to higher interfacial resistance between S4PH-35-PS and electrodes. While under low relative humidity (53% RH) at 80 °C, fuel cells based on S4PH-35-PS showed higher peak power density (234.9 mW/cm 2 ) than that (214.0 mW/cm 2 ) of Nafion 212.

  6. Sulfonation pathway inhibitors block reactivation of latent HIV-1.

    Science.gov (United States)

    Murry, Jeffrey P; Godoy, Joseph; Mukim, Amey; Swann, Justine; Bruce, James W; Ahlquist, Paul; Bosque, Alberto; Planelles, Vicente; Spina, Celsa A; Young, John A T

    2014-12-01

    Long-lived pools of latently infected cells are a significant barrier to the development of a cure for HIV-1 infection. A better understanding of the mechanisms of reactivation from latency is needed to facilitate the development of novel therapies that address this problem. Here we show that chemical inhibitors of the sulfonation pathway prevent virus reactivation, both in latently infected J-Lat and U1 cell lines and in a primary human CD4+ T cell model of latency. In each of these models, sulfonation inhibitors decreased transcription initiation from the HIV-1 promoter. These inhibitors block transcription initiation at a step that lies downstream of nucleosome remodeling and affects RNA polymerase II recruitment to the viral promoter. These results suggest that the sulfonation pathway acts by a novel mechanism to regulate efficient virus transcription initiation during reactivation from latency, and further that augmentation of this pathway could be therapeutically useful. Copyright © 2014. Published by Elsevier Inc.

  7. Thermochemical stability of Soviet macroporous sulfonated cation-exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Rukhlyada, N.N.; Plotnikova, V.P.; Roginskaya, B.S.; Znamenskii, Yu.P.; Zavodovskaya, A.S.; Dobrova, E.I.

    1988-10-20

    The purpose of this work was to study the influence of macroporosity on the thermochemical stability of sulfonated cation-exchangers. The investigations were carried out on commercial macroporous sulfonated cation-exchangers based on styrene-divinylbenzene copolymers. Study of the thermochemical stability of macroporous sulfonated cation-exchangers in dilute hydrogen peroxide solutions showed that the type of macroporosity has virtually no influence on their stability. The determining factor in thermal stability of macroporous cation-exchangers, as of the gel type, is the degree of cross-linking of the polymer matrix. The capacity loss of macroporous cation-exchangers during oxidative thermolysis is caused by destruction of the macromolecular skeleton and elution of fragments of polar chains containing sulfo groups into the solution.

  8. Electrochemical detection of dopamine using water-soluble sulfonated graphene

    International Nuclear Information System (INIS)

    Li, Su-Juan; He, Jun-Zhi; Zhang, Meng-Jie; Zhang, Rong-Xia; Lv, Xia-Lei; Li, Shao-Hua; Pang, Huan

    2013-01-01

    Graphical abstract: DPV responses of dopamine (DA) at sulfonated graphene based glassy carbon electrode in the presence of ascorbic acid (AA) and uric acid (UA). The separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA was about 227 mV, 125 mV and 352 mV, which allowed selectively determining DA. -- Abstract: In the present study, a biosensor was prepared using the water-soluble sulfonated graphene with the aim of achieving the selective and sensitive determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). The aromatic π–π stacking and electrostatic attraction between positively charged DA and negatively charged sulfonated graphene can accelerate the electron transfer whereas weakening AA and UA oxidation on the sulfonated graphene-modified electrode. Fourier transform infrared spectra (FTIR), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to characterize the successful synthesis of sulfonated graphene sheets. Differential pulse voltammetry was used for electrochemical detection, the separation of the oxidation peak potentials for AA-DA, DA-UA and UA-AA was about 227 mV, 125 mV and 352 mV, which allowed selectively determining DA. A broad linear range, low detection limit, along with good ability to suppress the background current from large excess ascorbic acid (AA) and uric acid (UA) were obtained. The as-prepared sulfonated graphene sheets exhibited superior performance over conventional negatively charged Nafion films, such as flexible film thickness, unique nanostructure, excellent anti-interference ability, high sensitivity and selectivity. The proposed method was used to detect DA in real hydrochloride injection sample, human urine and serum samples with satisfactory recovery results

  9. Evaluation of sulfonated carbon as catalyst in reactive distillation

    International Nuclear Information System (INIS)

    Orjuela, Alvaro; Civetta, Nicolas; Rivera, Jairo; Boyaca, Alejandro; Diaz, Jesus

    2004-01-01

    A packed bed using sulfonated coal catalytic pellets was prepared using a Colombian anthracitic coal. Such pellets were introduced in a semi batch distillation column to which acetic acid and ethanol were fed in order to determine experimentally the feasibility of obtaining ethyl acetate by reactive distillation operation. The carbonaceous catalytic packing was characterized by total exchange capacity, potentiometric titration and BET area. Experimental tests were carried out using three acid/alcohol ratios. Results of such process are shown by reaction conversion and concentration in distillate and bottom products. The sulfonated coal showed catalytic activity in this esterification reaction, with conversions between 29-45%

  10. Ruthenium-catalyzed meta sulfonation of 2-phenylpyridines.

    Science.gov (United States)

    Saidi, Ourida; Marafie, Jameel; Ledger, Araminta E W; Liu, Po Man; Mahon, Mary F; Kociok-Köhn, Gabriele; Whittlesey, Michael K; Frost, Christopher G

    2011-12-07

    A selective catalytic meta sulfonation of 2-phenylpyridines was found to occur in the presence of (arene)ruthenium(II) complexes upon reaction with sulfonyl chlorides. The 2-pyridyl group facilitates the formation of a stable Ru-C(aryl) σ bond that induces a strong para-directing effect. Electrophilic aromatic substitution proceeds with the sulfonyl chloride to furnish a sulfone at the position meta to the chelating group. This new catalytic process offers access to atypical regioselectivity for reactions involving chelation-assisted cyclometalation. © 2011 American Chemical Society

  11. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    NARCIS (Netherlands)

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing

  12. Chemical Agent Performance of Sulfonated Ionomeric Membranes for Chem/Bio Applications

    Science.gov (United States)

    2008-12-01

    Polyisobutylene ( PIB ) Chemically Modified IB Sulfonic Acid Counter-ion (Ba, Mg, Ca, Zn, Cs)Block Copolymer Morphology Sulfonic acid...Mauritz, K., 2000: Diffusion of Alcohols Through Sulfonated PS/ PIB /PS Block Copolymers Using FTIR-ATR Spectroscopy, Polymer Materials: Engineering

  13. 21 CFR 172.824 - Sodium mono- and dimethyl naphthalene sulfonates.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium mono- and dimethyl naphthalene sulfonates... FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.824 Sodium mono- and dimethyl naphthalene sulfonates. The food additive sodium mono- and dimethyl naphthalene sulfonates may be safely used in...

  14. 40 CFR 417.90 - Applicability; description of the oleum sulfonation and sulfation subcategory.

    Science.gov (United States)

    2010-07-01

    ... sulfonation and sulfation subcategory. 417.90 Section 417.90 Protection of Environment ENVIRONMENTAL... CATEGORY Oleum Sulfonation and Sulfation Subcategory § 417.90 Applicability; description of the oleum sulfonation and sulfation subcategory. The provisions of this subpart are applicable to discharges resulting...

  15. 40 CFR 417.110 - Applicability; description of the SO3 solvent and vacuum sulfonation subcategory.

    Science.gov (United States)

    2010-07-01

    ... solvent and vacuum sulfonation subcategory. 417.110 Section 417.110 Protection of Environment... POINT SOURCE CATEGORY SO3 Solvent and Vacuum Sulfonation Subcategory § 417.110 Applicability; description of the SO3 solvent and vacuum sulfonation subcategory. The provisions of this subpart are...

  16. 40 CFR 721.9595 - Alkyl benzene sulfonic acids and alkyl sulfates, amine salts (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl benzene sulfonic acids and alkyl... Significant New Uses for Specific Chemical Substances § 721.9595 Alkyl benzene sulfonic acids and alkyl...) The chemical substances identified generically as alkyl benzene sulfonic acids and alkyl sulfates...

  17. Enhanced antifouling and antibacterial properties of poly (ether sulfone) membrane modified through blending with sulfonated poly (aryl ether sulfone) and copper nanoparticles

    Science.gov (United States)

    Zhang, Jingjing; Xu, Ya'nan; Chen, Shouwen; Li, Jiansheng; Han, Weiqing; Sun, Xiuyun; Wu, Dihua; Hu, Zhaoxia; Wang, Lianjun

    2018-03-01

    A series of novel blend ultrafiltration (UF) membranes have been successfully prepared from commercial poly (ether sulfone), lab-synthesized sulfonated poly (aryl ether sulfone) (SPAES, 1 wt%) and copper nanoparticles (0 ∼ 0.4 wt%) via immersion precipitation phase conversion. The micro-structure and separation performance of the membranes were characterized by field emission scanning electron microscopy (SEM) and cross-flow filtration experiments, respectively. Sodium alginate, bovine serum albumin and humic acid were chosen as model organic foulants to investigate the antifouling properties, while E. coil was used to evaluate the antibacterial property of the fabricated membranes. By the incorporation with SPAES and copper nanoparticles, the hydrophilicity, antifouling and antibacterial properties of the modified UF membranes have been profoundly improved. At a copper nanoparticles content of 0.4 wt%, the PES/SPAES/nCu(0.4) membrane exhibited a high pure water flux of 193.0 kg/m2 h, reaching the smallest contact angle of 52°, highest flux recovery ratio of 79% and largest antibacterial rate of 78.9%. Furthermore, the stability of copper nanoparticles inside the membrane matrix was also considerably enhanced, the copper nanoparticles were less than 0.08 mg/L in the effluent during the whole operation.

  18. 21 CFR 177.2210 - Ethylene polymer, chloro-sulfonated.

    Science.gov (United States)

    2010-04-01

    ... reference. Copies of the ASTM method may be obtained from the American Society for Testing Materials, 100... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene polymer, chloro-sulfonated. 177.2210... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only...

  19. Thermoanalytical Investigation of Some Sulfone-Containing Drugs

    OpenAIRE

    Salama, Nahla N.; El Ries, Mohammed A.; Toubar, Safaa; Abd El Hamid, Maha; Walash, Mohammed I.

    2012-01-01

    The thermal behavior of some sulfone-containing drugs, namely, dapsone (DDS), dimethylsulfone (MSM), and topiramate (TOP) in drug substances, and products were investigated using different thermal techniques. These include thermogravimetry (TGA), derivative thermogravimetry (DTG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). The thermogravimetric data allowed the determination of the kinetic parameters: activation energy (E a ), frequency factor (A), and r...

  20. Sorption of perfluorooctane sulfonate to carbon nanotubes in aquatic sediments

    NARCIS (Netherlands)

    Kwadijk, C.J.A.F.; Velzeboer, I.; Koelmans, A.A.

    2013-01-01

    To date, sorption of organic compounds to nanomaterials has mainly been studied for the nanomaterial in its pristine state. However, sorption may be different when nanomaterials are buried in sediments. Here, we studied sorption of Perfluorooctane sulfonate (PFOS) to sediment and to sediment with 4%

  1. Sulfonated polyimides containing triphenylphosphine oxide for proton exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Arun Kumar; Bera, Debaditya; Banerjee, Susanta, E-mail: susanta@matsc.iitkgp.ernet.in

    2016-09-15

    A series of sulfonated co-polyimides (co-SPI) were prepared by one pot polycondensation reaction of a combination of diamines namely; 4,4′-diaminostilbene-2,2′-disulfonic acid (DSDSA) and prepared non-sulfonated diamine (DATPPO) containing triphenylphosphine oxide with 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA). All these soluble co-SPI gave flexible membranes with high thermal stability and showed good mechanical property. Transmission electron microscopy (TEM) analysis revealed the microphase separated morphology with well-dispersed hydrophilic (cluster size in the range of 5–55 nm) domains. The co-SPI membranes showed high oxidative and hydrolytic stability with higher proton conductivity. All these co-SPI membranes exhibited low water uptake and swelling ratio. The co-SPI membrane TPPO-60 (60% degree of sulfonation) with IEC{sub W} = 1.84 mequiv g{sup −1} showed high proton conductivity (99 mS cm{sup −1} at 80 °C and 107 mS cm{sup −1} at 90 °C) in water with high oxidative (20 h) and hydrolytic stability (only 5% degradation in 24 h). - Highlights: • Triphenylphosphine oxide containing sulfonated polyimides (SPIs) was synthesized. • The SPIs showed good oxidative and hydrolytic stability and high proton conductivity. • TEM analysis revealed well separated morphology of the SPIs.

  2. Homolytic C-O cleavage in phosphates and sulfonates.

    Science.gov (United States)

    Ding, Lanlan; Zheng, Wenrui; Wang, Yingxing

    2015-04-09

    The C-O homolytic bond dissociation enthalpies(BDEs) were calculated by high-level ab initio including G4, G3B3, G3, CBS-QB3 and a series of density function theory (DFT) methods. It is found that the wB97 method gave the most reliable C-O BDEs and the root-mean-square deviation (RMSD) is 7.6 kJ/mol. Therefore, the C(sp(2))-O BDE predictions and the substituent effects of alkenyl phosphates/sulfonates and aryl phosphates/sulfonates were investigated in detail by using the wB97 method. Interestingly, there exist different substituent effects in α- and β-substituted alkenyl phosphates/sulfonates. Excellent linear relationships between the C-O BDEs of β-substituted alkenyl phosphates/sulfonates with substituent constant σp(+) were found. In addition, the NBO analysis further disclosed the essence of the substituent effects on C-O BDEs.

  3. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

    Directory of Open Access Journals (Sweden)

    Das G

    2015-08-01

    Full Text Available Gautam Das, Hyon Hee Yoon Department of Chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-do, South Korea Abstract: An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 µA·cm-2·mM-1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. Keywords: electrochemical deposition, sulfonated graphene oxide, urease

  4. Fast atom bombardment mass spectrometry of condensed tannin sulfonate derivatives

    Science.gov (United States)

    J.J. Karchesy; L.Y. Foo; Richard W. Hemingway; E. Barofsky; D.F. Barofsky

    1989-01-01

    Condensed tannin sulfonate derivatives were studied by fast atom bombardment mass spectrometry (FAB-MS) to assess the feasibility of using this technique for determining molecular weight and structural information about these compounds. Both positive- and negative-ion spectra provided useful data with regard to molecular weight, cation species present, and presence of...

  5. Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

    Science.gov (United States)

    Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

    2010-10-19

    An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

  6. An investigation of proton conductivity of binary matrices sulfonated ...

    Indian Academy of Sciences (India)

    Ion exchange capacity of SPSU was determined as 3.05 mmol−1/g. The polymer electrolyte ... high temperature. In addition, they are also blended with polyvinyl imidazole9 and polyvinyl triazole.10. Sulfonated polysulfone (SPSU) is one of the acid func- .... 700◦C under N2 atmosphere at a scanning rate of 10◦C min−1.

  7. Structure and properties of compositions based on petroleum sulfonic acids

    Energy Technology Data Exchange (ETDEWEB)

    Tutorskii, I.A.; Sultanova, A.S.; Belkina, E.V.; Fomin, A.G. [Lomonosov Academy of Fine Chemical Technology, Moscow (Russian Federation)

    1995-03-01

    Colloidal characteristics of compositions based on petroleum sulfonic acids were studied. Neutralized heavy oil residue exhibits surface-active properties and contains an ultradisperse filler. Analysis of the compositions by size-exclusion-chromatography shows deep structural changes in the heavy acid residue upon neutralization with calcium carbonate.

  8. Petroleum sulfides, sulfoxides, and sulfones used as extragents

    International Nuclear Information System (INIS)

    Nikitin, Yu.E.; Lyapina, N.K.; Murinov, Yu.I.

    1988-01-01

    Possibilities of using petroleum sulfides, sulfoxides and sulfones for extraction and separation of wide range of elements are considered. It is shown that petroleum sulfides appear to be effective and selective extractants in extraction and separation of noble metals (Ru, Au, Pt, etc.). Petroleum sulfoxides are promising for solvent extraction of transition metals, actinides, rare earths etc

  9. Efficient synthesis and sulfonation of ordered mesoporous carbon materials.

    Science.gov (United States)

    Hou, Keke; Zhang, Anfeng; Gu, Lin; Liu, Min; Guo, Xinwen

    2012-07-01

    Ordered mesoporous carbons (OMCs) with hexagonal structure were efficiently synthesized via cooperative self-assembly of phenol/formaldehyde resol and surfactant F127 under acidic aqueous conditions. Induced by HCl, a gel phase mainly containing phenol/formaldehyde resol and F127 was obtained within several hours. X-ray diffraction (XRD), transmission electron microscope (TEM) and nitrogen adsorption isotherms indicated that the synthesized samples possess 2-D hexagonal mesostructure. The influence of the synthesis conditions, including acid concentration and mass ratio of resol to F127, was investigated. When the acid concentration was fixed in the range of 0.6-2.0 M and the mass ratio of resol to F127 in the range of 3.5-4.0, highly ordered mesoporous carbon could be synthesized. The synthesized OMCs could be easily sulfonated in concentrated sulfuric acid at elevated temperature. The results indicate that the mesostructural stability and the content of the surface sulfonic acid (SO(3)H) groups depend mainly on the pyrolysis temperature of the OMCs and the sulfonation temperature, suggesting that the combination of pyrolysis and sulfonation temperature is essential for developing OMCs with high densities of SO(3)H groups. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Sulfonated carbon black-based composite membranes for fuel cell ...

    Indian Academy of Sciences (India)

    Sci., Vol. 36, No. 4, August 2013, pp. 563–573. c Indian Academy of Sciences. Sulfonated carbon black-based composite membranes for fuel cell applications .... All data were collected from a second heating cycle and glass tran- sition temperatures (Tg) were calculated as a midpoint of thermogram. 2.5d FTIR studies: FTIR ...

  11. Toxicokinetics of perfluorooctane sulfonate in rainbow trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Rainbow trout (Oncorhynchus mykiss) confined to respirometer-metabolism chambers were dosed with perfluorooctane sulfonate (PFOS) by intra-arterial injection and sampled to obtain concentration time-course data for plasma, and either urine or expired water. The data were then an...

  12. Molecular Design of Sulfonated Triblock Copolymer Permselective Membranes

    Science.gov (United States)

    2008-07-03

    forcefields (interaction potentials) for the chemicals and functional groups present in the system. The forcefiled development requires quantum mechanical ab...molecules that form hydrogen bonds to the sulfonate group [2, 10] is somewhat higher in sPS solution. The geometrical analisys for hydrogen bonding

  13. Solid-supported sulfonic acid-containing catalysts efficiently ...

    Indian Academy of Sciences (India)

    Silica-functionalized sulfonic acid (SFSA) and sulfuric acid-modified polyethylene glycol-6000 (PEG-OSO3H) efficiently catalysed one-pot multi-component condensation of enolizable ketones or alkyl acetoacetates with arylaldehydes, acetonitrile and acetyl chloride to afford the corresponding -acetamido ketone or ester ...

  14. Proton exchange membranes from sulfonated polyetheretherketone and sulfonated polyethersulfone-cardo blends: Conductivity, water sorption and permeation properties

    International Nuclear Information System (INIS)

    Li, Yongli; Nguyen, Quang Trong; Schaetzel, Pierre; Lixon-Buquet, Camille; Colasse, Laurent; Ratieuville, Vincent

    2013-01-01

    Five blend membranes were prepared by solvent evaporation from solutions of the synthesized sulfonated polyetheretherketone (SPEEK) and sulfonated polyethersulfone-cardo (SPESc). Their ion exchange capacity and degree of sulfonation determined by acid–base titration and by thermogravimetric analysis were consistent. The blends glass transition behavior obtained by differential scanning calorimetry suggests that the two sulfonated polymers are compatible in the whole composition range. The values of the activation energy for proton transport determined by conductivity measurements on the SPEEK-based blend membranes were in the range of 13–34 kJ mol −1 , which suggest a mixed transport mechanism that involves both proton jumps on ionic sites and water of hydration and diffusion of proton–water complex in hydrophilic domains. The water vapor sorption in the membranes exhibits sigmoid-shape isotherms which were well fitted by the “new dual mode sorption” model, and the fitted parameters values were successfully used to model the change in the water permeation flux with the upstream water activity using the first Fick's diffusion equation. The fast increase in the permeation flux beyond a critical value of activity (0.5) was owing to the exponential concentration-dependent diffusion coefficient. These modelings allowed us to show a strong increase in the limit diffusion coefficient of water and a decrease in the water-diffusion plasticization coefficient with the SPEEK content in the polymer blends

  15. Aligned electrospun nanofibers as proton conductive channels through thickness of sulfonated poly (phthalazinone ether sulfone ketone) proton exchange membranes

    Science.gov (United States)

    Gong, Xue; He, Gaohong; Wu, Yao; Zhang, Shikai; Chen, Bo; Dai, Yan; Wu, Xuemei

    2017-08-01

    A novel approach is proposed to fabricate sulfonated poly (phthalazinone ether sulfone ketone) (SPPESK) proton exchange membranes with ordered through-plane electrospinning nanofibers, which provide nano-scale through-plane proton conductive channels along the thickness direction of the membranes, aiming to satisfy the challenging requirement of high through-plane proton conductivity in fuel cell operations. Induced by electrostatic attraction of strong electric field, the negatively charged sulfonic acid groups tend to aggregate towards surface of the electrospun fibers, which is evidenced by TEM and SAXS and further induces aggregation of the sulfonic acid groups in the SPPESK inferfiber voids filler along the surface of the nanofibers. The aligned electrospun nanofibers carries long-range ionic clusters along the thickness direction of the membrane and results in much higher total through-plane conductivity in the thickness aligned electrospun membranes, nearly twice as much as that of the cast SPPESK membrane. With smooth treatment, the thickness aligned electrospun SPPESK membranes exhibit higher single cell power density and tensile strength as compared with Nafion 115 (around 1.2 and 1.5 folds, respectively). Such a design of thickness aligned nano-size proton conductive channels provide feasibility for high performance non-fluorinated PEMs in fuel cell applications.

  16. Synthesis and Characterization of Sulfonated Graphene Oxide Reinforced Sulfonated Poly (Ether Ether Ketone) (SPEEK) Composites for Proton Exchange Membrane Materials.

    Science.gov (United States)

    Cao, Ning; Zhou, Chaofan; Wang, Yong; Ju, Hong; Tan, Dongyang; Li, Jin

    2018-03-28

    As a clean energy utilization device, full cell is gaining more and more attention. Proton exchange membrane (PEM) is a key component of the full cell. The commercial-sulfonated, tetrafluoroethylene-based fluoropolymer-copolymer (Nafion) membrane exhibits excellent proton conductivity under a fully humidified environment. However, it also has some disadvantages in practice, such as high fuel permeability, a complex synthesis process, and high cost. To overcome these disadvantages, a low-cost and novel membrane was developed. The sulfonated poly (ether ether ketone) (SPEEK) was selected as the base material of the proton exchange membrane. Sulfonated graphene (SG) was cross-linked with SPEEK through the elimination reaction of hydrogen bonds. It was found that the sulfonic acid groups and hydrophilic oxygen groups increased obviously in the resultant membrane. Compared with the pure SPEEK membrane, the SG-reinforced membrane exhibited better proton conductivity and methanol permeability prevention. The results indicate that the SG/SPEEK could be applied as a new proton exchange membrane in fuel cells.

  17. Synthesis and Characterization of Sulfonated Graphene Oxide Reinforced Sulfonated Poly (Ether Ether Ketone (SPEEK Composites for Proton Exchange Membrane Materials

    Directory of Open Access Journals (Sweden)

    Ning Cao

    2018-03-01

    Full Text Available As a clean energy utilization device, full cell is gaining more and more attention. Proton exchange membrane (PEM is a key component of the full cell. The commercial-sulfonated, tetrafluoroethylene-based fluoropolymer-copolymer (Nafion membrane exhibits excellent proton conductivity under a fully humidified environment. However, it also has some disadvantages in practice, such as high fuel permeability, a complex synthesis process, and high cost. To overcome these disadvantages, a low-cost and novel membrane was developed. The sulfonated poly (ether ether ketone (SPEEK was selected as the base material of the proton exchange membrane. Sulfonated graphene (SG was cross-linked with SPEEK through the elimination reaction of hydrogen bonds. It was found that the sulfonic acid groups and hydrophilic oxygen groups increased obviously in the resultant membrane. Compared with the pure SPEEK membrane, the SG-reinforced membrane exhibited better proton conductivity and methanol permeability prevention. The results indicate that the SG/SPEEK could be applied as a new proton exchange membrane in fuel cells.

  18. Solvation molar enthalpies and heat capacities of n-alkanes and n-alkylbenzenes on stationary phases of wide-ranging polarity.

    Science.gov (United States)

    Lebrón-Aguilar, Rosa; Quintanilla-López, Jesús Eduardo; Santiuste, José María

    2010-12-03

    A comparison of the most usual gas chromatographic methods for the calculation of partial molar enthalpies of solvation (Δ(sol)H(o)) has been carried out. Those methods based on the fitting of lnV(g) or ln(k/T) vs. 1/T and ln(k/T) vs. (1/T and the temperature arrangement, T(a)) are the most adequate ones for obtaining Δ(sol)H(o) values. However, the latter is the only reliable option for Δ(sol)H(o) estimation when commercial WCOT capillary columns are used, since in this case the estimation of some variables involved in the V(g) determination is less accurate or even impossible. Consequently, in this paper, Δ(sol)H(o) obtained from ln(k/T) vs. (1/T+T(a)) fitting at 373.15 and 298.15K for n-alkanes and n-alkylbenzenes on 12 commercial capillary columns coated with stationary phases covering the 203-3608 McReynolds polarity range are reported. Moreover, molar heat capacities of solvation at constant pressure (Δ(sol)C(p)(o)) have also been calculated using this method. A clear influence on Δ(sol)H(o) of the type and content of the substitution group in the stationary phase was observed. In addition, a linear relationship of Δ(sol)C(p)(o) with the van der Waals volume of the n-alkanes and the temperature gradient of density of the stationary phase was found. The effect of the size of the hydrocarbon on both thermodynamic variables was also investigated. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. Impact of model perfume molecules on the self-assembly of anionic surfactant sodium dodecyl 6-benzene sulfonate.

    Science.gov (United States)

    Bradbury, Robert; Penfold, Jeffrey; Thomas, Robert K; Tucker, Ian M; Petkov, Jordan T; Jones, Craig; Grillo, Isabelle

    2013-03-12

    The impact of two model perfumes with differing degrees of hydrophobicity/hydrophilicity, linalool (LL) and phenylethanol (PE), on the solution structure of anionic surfactant sodium dodecyl 6-benzene sulfonate, LAS-6, has been studied by small angle neutron scattering, SANS. For both types of perfume molecules, complex phase behavior is observed. The phase behavior depends upon the concentration, surfactant/perfume composition, and type of perfume. The more hydrophilic perfume PE promotes the formation of more highly curved structures. At relatively low surfactant concentrations, small globular micelles, L1, are formed. These become perfume droplets, L(sm), stabilized by the surfactant at much higher perfume solution compositions. At higher surfactant concentrations, the tendency of LAS-6 to form more planar structures is evident. The more hydrophobic linalool promotes the formation of more planar structures. Combined with the greater tendency of LAS-6 to form planar structures, this results in the planar structures dominating the phase behavior for the LAS-6/linalool mixtures. For the LAS-6/linalool mixture, the self-assembly is in the form of micelles only at the lowest surfactant and perfume concentrations. Over most of the concentration-composition space explored, the structures are predominantly lamellar, L(α), or vesicle, L(v), or in the form of a lamellar/micellar coexistence. At low and intermediate amounts of LL, a significantly different structure is observed, and the aggregates are in the form of small, relatively monodisperse vesicles (i.e., nanovesicles), L(sv).

  20. Las Sinapsis

    OpenAIRE

    Jorge Eduardo Duque Parra; Genaro Morales Parra; Carlos Alberto Duque Parra

    1997-01-01

    Introducción

    El estudio del sistema nervioso considera entre múltiples conexiones, aquéllas de carácter bioquímico que se median a través de sustancias elaboradas por las neuronas y que reciben la denominación de neurotransmisores’, dichas sustancias se vierten en las zonas de resquicio neuromuscular, neuroneuronal o neuroglandular, para modificar las condiciones de membrana y permitir la continuidad de los p...

  1. Mortar modified with sulfonated polystyrene produced from waste plastic cups

    Directory of Open Access Journals (Sweden)

    L. A. C. MOTTA

    Full Text Available Abstract In this work, we studied the addition of sulfonated polystyrene produced from waste plastic cups as an admixture for mortars. Mortars were analyzed with polystyrene content of 0.0; 0.2; 0.6; 1.0 and 1.4% in relation to the cement mass. The influence of polystyrene on the mortars' properties was evaluated by the consistency index, water retention, water absorption, porosity, elasticity modulus, compressive strength, flexural strength, bond tensile strength and microscopy. The increase in the sulfonated polystyrene content decreased the elasticity modulus of the mortar and, despite higher porosity, there was a reduction of water absorption by capillarity. In relation to mortar without admixture, the modified mortar showed an increase in water retention and consistency index, and a large increase in flexural strength and bond tensile strength. The significant increase of bond tensile strength (214% with admixture 1% highlights the potential of the produced material as an adhesive mortar.

  2. Brine-resistant sulfonate surfactants for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Stournas, S.

    1983-01-01

    One of the most severe limitations of surfactant waterflooding is the instability of the commonly employed surfactants in the usual ionic environments of oil reservoirs. A specific modification to the usual structure of sulfonate surfactants not only makes them immune to high concentrations of monovalent and divalent cations, but also enables them to act as stabilizer of the common surfactants and to displace tertiary oil in brines of high salinity and divalent ion content.

  3. Nucleophilic tetrafluoroethylation of carbonyl compounds with fluorinated sulfones

    Czech Academy of Sciences Publication Activity Database

    Václavík, Jiří; Chernykh, Yana; Jurásek, Bronislav; Beier, Petr

    2015-01-01

    Roč. 169, Jan (2015), s. 24-31 ISSN 0022-1139 R&D Projects: GA ČR GAP207/11/0421 Grant - others:GA MŠk(CZ) ED3.2.00/08.0144; GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : fluorine * tetrafluoroethylation * sulfones * nucleophilic addition * carbonyl compounds Subject RIV: CC - Organic Chemistry Impact factor: 2.213, year: 2015

  4. Effects of guandinoethane sulfonate on contraction of skeletal muscle.

    OpenAIRE

    Cuisinier, C; Gailly, Philippe; Francaux, Marc; Lebacq, Jean

    2000-01-01

    Guanidinoethane sulfonic acid (GES), a chemical and biological analog of taurine, decreases rat muscle taurine content when added to drinking water. Over the same period, GES appears in muscle. GES supplementation is often used to study the effect of taurine depletion on physiological mechanisms, without taking into account the possible actions of GES. The purpose of the present study was to investigate the specific actions of GES on contraction of skeletal muscle. In mice EDL muscle, the tim...

  5. Regioselective synthesis of chiral dimethyl-bis(ethylenedithiotetrathiafulvalene sulfones

    Directory of Open Access Journals (Sweden)

    Flavia Pop

    2015-07-01

    Full Text Available Enantiopure (R,R and (S,S-dimethyl-bis(ethylenedithiotetrathiafulvalene monosulfones have been synthesized by the aerial oxidation of the chiral dithiolates generated from the propionitrile-protected precursors. Both enantiomers crystallize in the orthorhombic chiral space group P212121. They show a boat-type conformation of the TTF moiety, a rather rigid dithiin sulfone ring and the methyl groups in a bisequatorial conformation. Cyclic voltammetry measurements indicate fully reversible oxidation in radical cation and dication species.

  6. Ultrasound assisted regioselective sulfonation of aromatic compounds with sulfuric acid.

    Science.gov (United States)

    Qureshi, Ziyauddin S; Deshmukh, Krishna M; Jagtap, Sachin R; Nandurkar, Nitin S; Bhanage, Bhalchandra M

    2009-03-01

    A simple and convenient methodology for selective sulfonation of aromatic compounds using sulfuric acid under sonication is described. The present methodology shows a considerable enhancement in the reaction rate along with improved selectivity compared with the reactions performed under silent conditions. The effect of various parameters such as agitation speed, sulfuric acid concentration, and temperature on reaction system have been investigated and are explained on the basis of ultrasonically generated cavitational effects.

  7. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

    Science.gov (United States)

    Das, Gautam; Yoon, Hyon Hee

    2015-01-01

    An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm−2·mM−1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. PMID:26346240

  8. Assembly of 1D Granular Structures from Sulfonated Polystyrene Microparticles

    Directory of Open Access Journals (Sweden)

    Alexander Mikkelsen

    2017-10-01

    Full Text Available Being able to systematically modify the electric properties of nano- and microparticles opens up new possibilities for the bottom-up fabrication of advanced materials such as the fabrication of one-dimensional (1D colloidal and granular materials. Fabricating 1D structures from individual particles offers plenty of applications ranging from electronic sensors and photovoltaics to artificial flagella for hydrodynamic propulsion. In this work, we demonstrate the assembly of 1D structures composed of individual microparticles with modified electric properties, pulled out of a liquid environment into air. Polystyrene particles were modified by sulfonation for different reaction times and characterized by dielectric spectroscopy and dipolar force measurements. We found that by increasing the sulfonation time, the values of both electrical conductivity and dielectric constant of the particles increase, and that the relaxation frequency of particle electric polarization changes, causing the measured dielectric loss of the particles to shift towards higher frequencies. We attributed these results to water adsorbed at the surface of the particles. With sulfonated polystyrene particles exhibiting a range of electric properties, we showed how the electric properties of individual particles influence the formation of 1D structures. By tuning applied voltage and frequency, we were able to control the formation and dynamics of 1D structures, including chain bending and oscillation.

  9. Sulfonation Disposition of Acacetin: In Vitro and in Vivo.

    Science.gov (United States)

    Zhang, Qisong; Zhu, Lijun; Gong, Xia; Ruan, Yanjiao; Yu, Jia; Jiang, Huangyu; Wang, Ying; Qi, XiaoXiao; Lu, Linlin; Liu, Zhongqiu

    2017-06-21

    Acacetin, an important component of acacia honey, exerts extensive therapeutic effects on many cancers. However, the sulfonation disposition of acacetin has rarely been reported. Therefore, this study aimed to investigate the sulfonation disposition of acacetin systematically. The results showed that acacetin-7-sulfate was the main metabolite mediated primarily by sulfotransferases (SULT) 1A1. Dog liver S9 presented the highest formation rate of acacetin-7-sulfate. Compared with that in wild-type Friend Virus B (FVB) mice, plasma exposure of acacetin-7-sulfate decreased significantly in multidrug resistance protein 1 knockout (Mrp1 -/- ) mice vut increased clearly in breast cancer resistance protein knockout (Bcrp -/- ) mice. In Caco-2 monolayers, the efflux and clearance of acacetin-7-sulfate was reduced distinctly by the BCRP inhibitor Ko143 on the apical side and by the MRP1 inhibitor MK571 on the basolateral side. In conclusion, acacetin sulfonation was mediated mostly by SULT1A1. Acacetin-7-sulfate was found to be transported mainly by BCRP and MRP1. Hence, SULT1A1, BCRP, and MRP1 are responsible for acacetin-7-sulfate exposure in vivo.

  10. Uptake and utilization of sulfonic acids in the cyanobacterial strains Anabaena variabilis and Plectonema 73110

    International Nuclear Information System (INIS)

    Biedlingmaier, S.; Schmidt, A.

    1987-01-01

    Growth of several cyanobacteria was examined on ethane sulfonate and taurine as only sulfur source. Comparing two strains with differential utilization of sulfonic acids (Anabaena variabilis and Synechococcus 6301) demonstrated that actual growth was coupled to the presence of an active sulfonate transport system due to species specific properties and nutritional conditions. Sulfonate uptake in Anabaena variabilis was characterized by a pH optimum of 6.5, a structural specificity for sulfonates, missing Na + dependence, and phosphate stimulation. Radiolabeled ethane sulfonate and taurine was metabolized to products of normal sulfur metabolism. Also considerable amounts of 35 S-labeled volatiles (mercaptanes and sulfide) could be detected, suggesting a degradation mechanism via reduction to mercaptanes and cleavage of the C-S bond. (orig.)

  11. Polymer sulfonation- a versatile route to prepare proton-conducting membrane material for advanced technologies

    International Nuclear Information System (INIS)

    Zaidi, S.M.J.

    2003-01-01

    Sulfonation of polymers is a viable method for making proton exchange membranes used in electrochemical devices. Polyether-ether ketone was modified by using concentrated sulfuric acid (97.4%) to produce ion-containing polymers bearing HSO3 groups. The sulfonated polymer was characterized for IEC, HNMR, DSC and water uptake etc. The degree of sulfonation of sulfonated PEEK was found to vary from 40 to 80 mol%. The PEEK became amorphous after sufonation (as evidenced from DSC and WXRD), which enhanced its solubility in organic solvents such as DMF. The glass transition temperature, Tg increased from 151C for pure PEEK to 217C upon sulfonation. The water uptake was also increased with sulfonation level, which provides formation of water-mediated pathways for protons involving SO3H groups. The membranes from these polymers have a high potential for use in electrochemical devices such as polymer fuel cell and electrodialysis. (author)

  12. Sulfonation and characterization of styrene-indene copolymers for the development of proton conducting polymer membranes

    Directory of Open Access Journals (Sweden)

    Cristiane M. Becker

    2012-01-01

    Full Text Available The aim of this work is to obtain polymer precursors based on styrene copolymers with distinct degrees of sulfonation, as an alternative material for fuel cell membranes. Acetyl sulfate was used to carry out the sulfonation and the performance of the polyelectrolyte was evaluated based on the content of acid polar groups incorporated into the macromolecular chain. Polymeric films were produced by blending the sulfonated styrene-indene copolymer with poly(vinylidene fluoride. The degree of sulfonation of the polymer was strongly affected by the sulfonation reaction parameters, with a direct impact on the ionic exchange capacity and the ionic conductivity of the sulfonated polymers and the membranes obtained from them. The films produced with the blends showed more suitable mechanical properties, although the conductivity of the membranes was still lower than that of commercially available membranes used in fuel cells.

  13. Proton Conduction in Sulfonated Organic-Inorganic Hybrid Monoliths with Hierarchical Pore Structure.

    Science.gov (United States)

    von der Lehr, Martin; Seidler, Christopher F; Taffa, Dereje H; Wark, Michael; Smarsly, Bernd M; Marschall, Roland

    2016-09-28

    Porous organic-inorganic hybrid monoliths with hierarchical porosity exhibiting macro- and mesopores are prepared via sol-gel process under variation of the mesopore size. Organic moieties in the pore walls are incorporated by substituting up to 10% of the silicon precursor tetramethylorthosilicate with bisilylated benzene molecules. After functionalization with sulfonic acid groups, the resulting sulfonated hybrid monoliths featuring a bimodal pore structure are investigated regarding proton conduction depending on temperature and relative humidity. The hierarchical pore system and controlled mesopore design turn out to be crucial for sulfonation and proton conduction. These sulfonated hybrid hierarchical monoliths containing only 10% organic precursor exhibit higher proton conduction at different relative humidities than sulfonated periodic mesoporous organosilica made of 100% bisilylated precursors exhibiting solely mesopores, even with a lower concentration of sulfonic acid groups.

  14. IR Laser Ablative Degradation of Poly(phenylene ether sulfone): Deposition of Films Containing Sulfone, Sulfoxide and Sulfide Groups

    Czech Academy of Sciences Publication Activity Database

    Blazevska-Gilev, J.; Bastl, Zdeněk; Šubrt, Jan; Stopka, Pavel; Pola, Josef

    2009-01-01

    Roč. 94, č. 2 (2009), s. 196-200 ISSN 0141-3910 R&D Projects: GA AV ČR IAA400720619 Institutional research plan: CEZ:AV0Z40720504; CEZ:AV0Z40400503; CEZ:AV0Z40320502 Keywords : laser ablation * laser-induced degradation * poly(1,4-phenylene ether-sulfone) Subject RIV: CH - Nuclear ; Quantum Chemistry Impact factor: 2.154, year: 2009

  15. Two-step sulfonation process for the conversion of polymer fibers to carbon fibers

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Bryan E.; Patton, Jasson T.; Hukkanen, Eric J.; Bernius, Mark T.

    2017-11-14

    Disclosed herein are processes for preparing carbon fibers, comprising: sulfonating a polymer fiber with a sulfonating agent that is fuming sulfuric acid, sulfuric acid, chlorosulfonic acid, or a combination thereof; treating the sulfonated polymer with a heated solvent, wherein the temperature of the heated solvent is at least 95.degree. C.; and carbonizing the resulting product by heating it to a temperature of 501-3000.degree. C. Carbon fibers prepared according to these methods are also disclosed herein.

  16. Camphorquinone-10-sulfonic acid and derivatives: Convenient reagents for reversible modification of arginine residues

    OpenAIRE

    Pande, Chandra S.; Pelzig, Michal; Glass, John D.

    1980-01-01

    Camphorquinone-10-sulfonic acid hydrate was prepared by the action of selenous acid on camphor-10-sulfonic acid. Camphorquinone-10-sulfonylnorleucine was prepared either from the sulfonic acid via the sulfonyl chloride or by selenous acid oxidation of camphor-10-sulfonylnorleucine. These reagents are useful for specific, reversible modification of the guanidino groups of arginine residues. Camphorquinonesulfonic acid is a crystalline water-soluble reagent that is especially suitable for use w...

  17. Measurements of photo-oxidation products from the reaction of a series of alkyl-benzenes with hydroxyl radicals during EXACT using comprehensive gas chromatography

    Directory of Open Access Journals (Sweden)

    J. F. Hamilton

    2003-01-01

    Full Text Available Photo-oxidation products from the reaction of a series of alkyl-benzenes, (benzene, toluene, p-xylene and 1,3,5-trimethyl-benzene with hydroxyl radicals in the presence of NOx have been investigated using comprehensive gas chromatography (GCxGC. A GCxGC system has been developed which utilises valve modulation and independent separations as a function of both volatility and polarity. A number of carbonyl-type compounds were identified during a series of reactions carried out at the European Photoreactor (EUPHORE, a large volume outdoor reaction chamber in Valencia, Spain. Experiments were carried as part of the EXACT project (Effects of the oXidation of Aromatic Compounds in the Troposphere. Two litre chamber air samples were cryo-focused, with a sampling frequency of 30 minutes, allowing the evolution of species to be followed over oxidation periods of 3-6 hours. To facilitate product identification, several carbonyl compounds, which were possible products of the photo-oxidation, were synthesised and used as reference standards. For toluene reactions, observed oxygenated intermediates found included the co-eluting pair a-angelicalactone/4-oxo-2-pentenal, maleic anhydride, citraconic anhydride, benzaldehyde and p-methyl benzoquinone. In the p-xylene experiment, the products identified were E/Z-hex-3-en-2,5-dione and citraconic anhydride. For 1,3,5-TMB reactions, the products identified were 3,5-dimethylbenzaldehyde, 3,5-dimethyl-3H-furan-2-one and 3-methyl-5-methylene-5H-furan-2-one. Preliminary quantification was carried out on identified compounds using liquid standards. Comparison of FTIR and GCxGC for the measurement of the parent aromatics generally showed good agreement. Comparison of the concentrations observed by GCxGC to concentration-time profiles simulated using the Master Chemical Mechanism, MCMv3, demonstrates that this mechanism significantly over-predicts the concentrations of many product compounds and highlights the

  18. Measurements of photo-oxidation products from the reaction of a series of alkyl-benzenes with hydroxyl radicals during EXACT using comprehensive gas chromatography

    Science.gov (United States)

    Hamilton, J. F.; Lewis, A. C.; Bloss, C.; Wagner, V.; Henderson, A. P.; Golding, B. T.; Wirtz, K.; Martin-Reviejo, M.; Pilling, M. J.

    2003-11-01

    Photo-oxidation products from the reaction of a series of alkyl-benzenes, (benzene, toluene, p-xylene and 1,3,5-trimethyl-benzene) with hydroxyl radicals in the presence of NOx have been investigated using comprehensive gas chromatography (GCxGC). A GCxGC system has been developed which utilises valve modulation and independent separations as a function of both volatility and polarity. A number of carbonyl-type compounds were identified during a series of reactions carried out at the European Photoreactor (EUPHORE), a large volume outdoor reaction chamber in Valencia, Spain. Experiments were carried as part of the EXACT project (Effects of the oXidation of Aromatic Compounds in the Troposphere). Two litre chamber air samples were cryo-focused, with a sampling frequency of 30 minutes, allowing the evolution of species to be followed over oxidation periods of 3-6 hours. To facilitate product identification, several carbonyl compounds, which were possible products of the photo-oxidation, were synthesised and used as reference standards. For toluene reactions, observed oxygenated intermediates found included the co-eluting pair a-angelicalactone/4-oxo-2-pentenal, maleic anhydride, citraconic anhydride, benzaldehyde and p-methyl benzoquinone. In the p-xylene experiment, the products identified were E/Z-hex-3-en-2,5-dione and citraconic anhydride. For 1,3,5-TMB reactions, the products identified were 3,5-dimethylbenzaldehyde, 3,5-dimethyl-3H-furan-2-one and 3-methyl-5-methylene-5H-furan-2-one. Preliminary quantification was carried out on identified compounds using liquid standards. Comparison of FTIR and GCxGC for the measurement of the parent aromatics generally showed good agreement. Comparison of the concentrations observed by GCxGC to concentration-time profiles simulated using the Master Chemical Mechanism, MCMv3, demonstrates that this mechanism significantly over-predicts the concentrations of many product compounds and highlights the uncertainties which exist in

  19. Las Sinapsis

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Duque Parra

    1997-12-01

    Full Text Available

    Introducción

    El estudio del sistema nervioso considera entre múltiples conexiones, aquéllas de carácter bioquímico que se median a través de sustancias elaboradas por las neuronas y que reciben la denominación de neurotransmisores’, dichas sustancias se vierten en las zonas de resquicio neuromuscular, neuroneuronal o neuroglandular, para modificar las condiciones de membrana y permitir la continuidad de los potenciales de acción (por creación de nuevos potenciales en las células subsiguientes, de la neurona hacia el órgano blanco.

    La integridad de los diversos elementos de la “zona de unión funcional” o sinapsis, asegura la adecuada comunicación entre el sistema nervioso y la mayoría de los elementos restantes del organismo humano.

    Las alteraciones de los elementos de las sinapsis, conllevan a la génesis de estados variables fisiológicos y patológicos somáticos, psicosomáticos o psíquicos, inconsecuentes con el estado de homeostasis.

    Las moléculas que se vierten en las hendiduras sinápticas, sirven, por tanto, de transductoras para efectos elementales (como los reflejos y en las estrategias complejas (como los de la actividad intelectual.

    Antecedentes

    Ya desde los tiempos de Galeno, se sabía que los nervios eran los responsables de la rápida comunicación entre el cuerpo y el cerebro; el estudio de las sinapsis nos remonta de manera indirecta a
    1791, fecha en la que Luigi Galvani, descubrió en sus experimentos con ancas de ranas, que entre los eventos eléctricos y los ocurridos en los nervios, existía una relación evidente (28,37,45’, los experimentos de Galvani se han refinado con el paso del tiempo, en nuestro siglo por ejemplo, el desarrollo del osciloscopio de rayos catódicos combinado con un amplificador potente, ha permitido medir las débiles y variables corrientes bioeléctricas de los

  20. Sulfonated phenolic material and its use in post primary oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Pardue, J. E.; Stapp, P. R.

    1984-09-04

    Sulfonated phenolic compounds as well as sulfomethylated phenolic compounds, surfactant systems containing such compound and the use of such surfactant systems in post primary oil recovery are disclosed.

  1. Cadmium ion sorption onto lignocellulosic biosorbent modified by sulfonation: the origin of sorption capacity improvement.

    Science.gov (United States)

    Shin, Eun Woo; Rowell, Roger M

    2005-08-01

    Juniper (Juniperus monosperma), a small-diameter underutilized material, has been studied as a lignocellulosic biosorbent for removing heavy metals from water. In this study, juniper wood was modified by sulfonation to enhance sorption capacity for cadmium in water. The origin of the enhancement was investigated by observing the sorption behaviors and the change in surface functional group concentrations. Cadmium sorption by all juniper wood biosorbents studied was fast and the sorption capacity decreased with decreasing pH, similar to results found for other biosorbents. Sulfonated juniper was found to have at least twice the sorption capacity for cadmium removal from water compared to that of untreated juniper, though the sorption capacity increased with increasing pH. A slight increase in carboxylate content after sulfonation was likely responsible for a small portion of the enhancement. Elemental analysis showed an increase in sulfur content after sulfonation. Diffuse reflectance infrared Fourier transform (DRIFT) spectra showed a decrease in the band at 1660 cm(-1) in the range of carbonyl groups as a result of sulfonation. This indicates that coniferaldehyde groups in the lignin of juniper wood corresponding to this band were substituted into sulfonic acid groups after sulfonation. This interpretation was supported by both the color forming reaction with phloroglucinol-hydrochloric acid and the reaction mechanisms from the acid sulfite pulping process. Consequently, the enhancement of cadmium sorption capacity of juniper wood by sulfonation mainly originated from the production of sulfonic acid groups, which are binding sites for heavy metals.

  2. Electrochemical synthesis and characterization of poly(3,4-ethylenedioxythiophene) doped with sulfonated calixarenes and sulfonated calixarene–fullerene complexes

    International Nuclear Information System (INIS)

    Dumitriu, Cristina; Mousavi, Zekra; Latonen, Rose-Marie; Bobacka, Johan; Demetrescu, Ioana

    2013-01-01

    Highlights: • PEDOT–C 60 composites were electrosynthesized from aqueous solution. • The surface morphology of PEDOT doped with sulfonated calixarene–C 60 complexes is very similar to that of PEDOT doped with the same sulfonated calixarenes without C 60 . • A remarkable increase in the electroactivity of PEDOT after contact with C 60 in organic solution was observed, which is interesting both from a fundamental point of view and for charge storage applications. -- Abstract: Poly(3,4-ethylenedioxythiophene) (PEDOT) films were electrochemically deposited on glassy carbon (GC) disk electrodes using aqueous solutions containing 3,4-ethylenedioxythiophene (EDOT) and sulfonated calixarenes or fullerene-sulfonated calixarene (C 60 –calixarene) complexes. The EDOT monomer was added to aqueous sulfonated calixarene solutions with and without C 60 and from these solutions PEDOT(calixarene) and PEDOT(C 60 –calixarene) films were electrochemically deposited on GC disk electrodes. The electrochemical properties of GC/PEDOT(C 60 –calixarene) were compared with those of GC/PEDOT doped with other ions, both in aqueous and organic electrolyte solutions using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV measurements carried out on GC/PEDOT(C 60 –calixarene) in 0.1 M aqueous KCl solution showed a reduction peak at ca. −0.55 V vs. Ag/AgCl/3 M KCl only during the first potential scan. This was attributed to the irreversible reduction of C 60 to C 60 − inside the PEDOT film. This additional reduction peak was, however, not observed when recording the CVs in organic solution, indicating that C 60 was dissolved from the PEDOT film into the organic electrolyte solution, that is a good solvent for C 60 . When performing CV measurements in an organic electrolyte solution containing C 60 , all GC/PEDOT electrodes with various doping ions and bare GC electrodes showed a reversible reduction peak characteristic for the C 60 /C 60 − redox

  3. Low-level Determination of Residual Methyl Methane Sulfonate and Ethyl Methane Sulfonate in Pharmaceuticals by Gas Chromatography with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    M. Sarat

    2010-01-01

    Full Text Available A capillary gas chromatographic method using mass spectrometric detection was developed and validated for the trace analysis (ppm level of methyl methane sulfonate and ethyl methane sulfonate in pharmaceutical drug substances. The method utilizes a capillary column (DB-624 with 6% cyanopropyl phenyl and 94% dimethyl polysiloxane stationary phase. A dissolve-and-injection approach was adopted for sample introduction in a split less mode. Mixture of (80:20 ratio of methanol and chloroform was used as a diluent or sample solvent. A limit of detection of about 0.17 μg/g (0.17 ppm for methyl methane sulfonate and 0.18 μg/g (0.18 ppm for ethyl methane sulfonate were achieved and limit of quantitation of 0.52 μg/g (0.52 ppm for methyl methane sulfonate and 0.54 μg/g (0.54 ppm for ethyl methane sulfonate were achieved for alkyl sulfonates in drug substance samples.

  4. Synthesis of highly branched sulfonated polymers and the effects of degree of branching on properties of branched sulfonated polymers as proton exchange membranes

    Science.gov (United States)

    Xie, Huixiong; Wang, Duan; Tao, Dan; Wang, Lei

    2014-09-01

    Branched sulfonated polymers exhibit excellent properties as proton exchange membranes (PEMs). However, very few highly branched sulfonated polymers are reported as PEMs. The highly branched polymer, including the method to increase degree of branching (DB) and the effects of DB on the properties of PEMs, should be further studied. In this work, novel branched sulfonated poly(fluorenyl ether ketone sulfone)s with different DB value are synthesized by direct polycondensation reactions from bisphenol fluorene (A2), sulfonated 4,4‧-difluorobenzphenone, 1,3,5-tris(4-(4-fluorophenylsulfonyl)phenyl)benzene (B3-3) and 4,4‧-difluorodiphenyl sulfone. The highest DB with 10% branching agent is obtained using the B3-3 monomer. The method to increase the DB is discussed. It is found that B3 scaffold with long and hard arms can effectively increase the DB value. The effects of DB on the properties, including oxidative stability, proton conductivity, water uptake, swelling ratio, thermal stability, mechanical property and microstructure, are investigated. With increasing DB value, oxidative stability and proton conductivity of the membranes increase remarkably, but swelling ratio and tensile strength decrease slowly. The membrane with the highest DB value (10%) exhibits high proton conductivity (0.42 S cm-1) and oxidative stability (327 min), as well as relatively low swelling ratio (16.2%) at 80 °C.

  5. Toltrazuril sulfone sodium salt: synthesis, analytical detection, and pharmacokinetics in the horse.

    Science.gov (United States)

    Dirikolu, L; Karpiesiuk, W; Lehner, A F; Tobin, T

    2012-06-01

    Toltrazuril sulfone (ponazuril) is a triazine-based antiprotozoal agent with clinical application in the treatment of equine protozoal myeloencephalomyelitis (EPM). In this study, we synthesized and determined the bioavailability of a sodium salt formulation of toltrazuril sulfone that can be used for the treatment and prophylaxis of EPM in horses. Toltrazuril sulfone sodium salt was rapidly absorbed, with a mean peak plasma concentration of 2400 ± 169 (SEM) ng/mL occurring at 8 h after oral-mucosal dosing and was about 56% bioavailable compared with the i.v. administration of toltrazuril sulfone in dimethylsulfoxide (DMSO). The relative bioavailability of toltrazuril sulfone suspended in water compared with toltrazuril sulfone sodium salt was 46%, indicating approximately 54% less oral bioavailability of this compound suspended in water. In this study, we also investigated whether this salt formulation of toltrazuril sulfone can be used as a feed additive formulation without significant reduction in oral bioavailability. Our results indicated that toltrazuril sulfone sodium salt is relatively well absorbed when administered with feed with a mean oral bioavailability of 52%. Based on these data, repeated oral administration of toltrazuril sulfone sodium salt with or without feed will yield effective plasma and cerebrospinal fluid (CSF) concentrations of toltrazuril sulfone for the treatment and prophylaxis of EPM and other protozoal diseases of horses and other species. As such, toltrazuril sulfone sodium salt has the potential to be used as feed additive formulations for both the treatment and prophylaxis of EPM and various other apicomplexan diseases. © 2011 Blackwell Publishing Ltd.

  6. Sulfonation of the resolving cysteine in human peroxiredoxin 1: A comprehensive analysis by mass spectrometry.

    Science.gov (United States)

    Wu, Changgong; Dai, Huacheng; Yan, Lin; Liu, Tong; Cui, Chuanglong; Chen, Tong; Li, Hong

    2017-07-01

    Peroxiredoxin 1 (Prx1) is an essential peroxidase that reduces cellular peroxides. It holds 2 indispensable cysteines for its activity: a peroxidatic cysteine (C P ) for peroxide reduction and a resolving cysteine (C R ) for C P regeneration. C P can be readily sulfonated to C P -SO 3 H by protracted oxidative stress, which inactivates Prx1 as a peroxidase. By comparison, sulfonation of C R to C R -SO 3 H in mammalian cells has only been reported once. The rare report of C R sulfonation prompts the following questions: "can C R -SO 3 H be detected more readily with the current high sensitivity mass spectrometers (MS)?" and "do C P and C R have distinct propensities to sulfonation?" Answers to these questions could shed light on how differential sulfonation of C P and C R regulates Prx1 functions in cells. We used a sensitive Orbitrap MS to analyze both basal and H 2 O 2 -induced sulfonation of C R and C P in either recombinant human Prx1 (rPrx1) or HeLa cell Prx1 (cPrx1). In the Orbitrap MS, we optimized both collision-induced dissociation and higher-energy collisional dissociation methods to improve the analytical sensitivity of cysteine sulfonation. In the basal states without added H 2 O 2 , both C P and C R were partially sulfonated in either rPrx1 or cPrx1. Still, exogenous H 2 O 2 heightened the sulfonation levels of both C P and C R by ~200-700%. Titration with H 2 O 2 revealed that C P and C R possessed distinct propensities to sulfonation. This surprising discovery of prevalent Prx1 C R sulfonation affords a motivation for future investigation of its precise functions in cellular stress response. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Benzyl-tributyl-ammonium 7-hydroxy-naphthalene-1-sulfonate.

    Science.gov (United States)

    Sato, Yohei; Uta, Kazuya; Mizuguchi, Jin

    2009-01-17

    The title compound, C(19)H(34)N(+)·C(10)H(7)O(4)S(-), is a charge-control agent used for toners in electrophotography. The anions form one-dimensional chains by O-H⋯O hydrogen bonds in a zigzag fashion along the c axis between the OH group of one anion and the sulfonate O atom of a neighboring anion. One of the n-butyl chains of the cation is disordered over two sites in a 0.77:0.23 ratio.

  8. Benzyl-tributyl-ammonium 6-hydroxy-naphthalene-2-sulfonate.

    Science.gov (United States)

    Uta, Kazuya; Sato, Yohei; Mizuguchi, Jin

    2009-01-17

    The title compound, C(19)H(34)N(+)·C(10)H(7)O(4)S(-), is a charge-control agent for toners used in electrophotography. Inter-moleclar O-H⋯O hydrogen bonding between the OH group of one anion and the sulfonate O atom of a neighboring anion leads to the formation of one-dimensional chains along the b axis. In addition, C-H⋯O hydrogen bonds are observed. One of the n-butyl chains of the cation is disordered over two sites in a 0.88:0.12 ratio.

  9. Poly(oxyethylene) electrolytes based on lithium pentafluorobenzene sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Paillard, E.; Iojoiu, C.; Alloin, F.; Guindet, J.; Sanchez, J.-Y. [LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, UMR 5631 CNRS-INPG-UJF, BP 75, 38402 Saint-Martin-d' Heres Cedex (France)

    2007-03-01

    Lithium pentafluorobenzene sulfonate was synthesized by a protocol whereby pollution by aromatic nucleophilic substitutions on the perfluorinated ring was avoided. Its poly(oxyethylene) complexes, although less conductive than lithium imide complexes, provided cationic transference numbers higher than 0.5. Surprisingly, even at fairly low concentrations, this salt markedly increased the mechanical properties of the polymer electrolyte. This effect was attributed to telechelic interactions of the ion pairs with distinct polyether chains and is in agreement with the high cationic transference numbers. (author)

  10. Mechanocatalytic Depolymerization of Cellulose With Perfluorinated Sulfonic Acid Ionomers

    Directory of Open Access Journals (Sweden)

    Ayman Karam

    2018-03-01

    Full Text Available Here, we investigated that the mechanocatalytic depolymerization of cellulose in the presence of Aquivion, a sulfonated perfluorinated ionomer. Under optimized conditions, yields of water soluble sugars of 90–97% were obtained using Aquivion PW98 and PW66, respectively, as a solid acid catalyst. The detailed characterization of the water soluble fraction revealed (i the selective formation of oligosaccharides with a DP up to 11 and (ii that depolymerization and reversion reactions concomitantly occurred during the mechanocatalytic process, although the first largely predominated. More importantly, we discussed on the critical role of water contained in Aquivion and cellulose on the efficiency of the mechanocatalytic process.

  11. Las Farmacodependencias

    OpenAIRE

    José Francisco Socarrás

    1994-01-01

    Ahora, cuando la Corte Constitucional ha despenalizado al farmacodependiente por el consumo de drogas, conviene informar sobre las consecuencias perjudiciales de estas. A quienes deseen un conocimiento detallado al respecto, les recomiendo documentarse en “Enciclopedia de Psiquiatría”, publicada por “El Ateneo” en Buenos Aires.

    El Capítulo respectivo es del doctor Daniel L. Murguia. El denominador corriente de su abuso es sencillamente la dependencia, nombre propues...

  12. Las incumbencias

    Directory of Open Access Journals (Sweden)

    Emilio Fermín Mignone

    2013-05-01

    Full Text Available Desde mediados de la década de 1970 se desarrolló en la Argentina un sistema dirigido a establecer las denominadas incumbencias de las profesiones universitarias, que ha alcanzado notable dimensión. Sin embargo, no conozco hasta el presente un análisis pormenorizado de su evolución ni de sus fundamentos legales; ni una reflexión acerca de sus propósitos, ventajas e inconvenientes. El propósito de este trabajo es iniciar dicho examen para contribuir con una propuesta racional al desenvolvimiento de una política universitaria orientada hacia el acrecentamiento de la autonomía de los establecimientos, la distinción entre el título académico y la habilitación profesional, la desregulación, en la medida de lo razonable, del ejercicio de las profesiones y la evaluación periódica de la calidad de la educación superior, a fin de procurar su excelencia, pertinencia, eficiencia y equidad

  13. Sulfonate Functionalisation of Transition Metal Complexes: A Versatile Tool Towards Catalyst Recovery

    NARCIS (Netherlands)

    Virboul, M.A.N.|info:eu-repo/dai/nl/304837709

    2011-01-01

    This thesis describes the synthesis and application of sulfonate-functionalised ligands in organometallic chemistry and (aqueous) catalysis. Due to their ability to trigger specific solubility, different NHC ligand precursors bearing a butyl-sulfonate chain were synthesised. The formation of

  14. Synthesis and Structure-Property Relationships of Poly(sulfone)s for Anion Exchange Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Yan, JL; Moore, HD; Hibbs, MR; Hickner, MA

    2013-10-05

    Membranes based on cationic polymers that conduct anions are important for enabling alkaline membrane fuel cells and other solid-state electrochemical devices that operate at high pH. Anion exchange membranes with poly(arylene ether sulfone) backbones are demonstrated by two routes: chloromethylation of commercially available poly(sulfone)s or radical bromination of benzylmethyl moieties in poly(sulfone)s containing tetramethylbisphenol A monomer residues. Polymers with tethered trimethylbenzyl ammonium moieties resulted from conversion of the halomethyl groups by quaternization with trimethyl amine. The water uptake of the chloromethylated polymers was dependent on the type of poly(sulfone) backbone for a given IEC. Bisphenol A-based Udel (R) poly(sulfone) membranes swelled in water to a large extent while membranes from biphenol-based Radel (R) poly(sulfone), a stiffer backbone than Udel, only showed moderate water uptake. The water uptake of cationic poly(sulfone)s was further reduced by synthesizing tetramethylbisphenol A and 4,4-biphenol-containing poly(sulfone) copolymers where the ionic groups were clustered on the tetramethylbisphenol A residues. The conductivity of all samples scaled with the bulk water uptake. The hydration number of the membranes could be increased by casting membranes from the ionic form polymers versus converting the halomethyl form cast polymers to ionic form in the solid state. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013, 51, 1790-1798, 2013

  15. Cationic and radical intermediates in the acid photorelease from aryl sulfonates and phosphates.

    Science.gov (United States)

    Terpolilli, Marco; Merli, Daniele; Protti, Stefano; Dichiarante, Valentina; Fagnoni, Maurizio; Albini, Angelo

    2011-01-01

    The irradiation of a series of phenyl sulfonates and phosphates leads to the quantitative release of acidity with a reasonable quantum yield (≈0.2). Products characterization, ion chromatography analysis and potentiometric titration are consistent with the intervening of two different paths in this reaction, viz. cationic with phosphates and (mainly) radical with sulfonates.

  16. Reaction of arylsulfonylhydrazones of aldehydes with alpha-magnesio sulfones. A novel olefin synthesis.

    Science.gov (United States)

    Kurek-Tyrlik, A; Marczak, S; Michalak, K; Wicha, J; Zarecki, A

    2001-10-19

    Reactions of representative tosylhydrazones of aldehydes and ketones with alpha-metalated sulfones were examined in order to develop a practical olefination method. Treatment of aldehyde tosylhydrazone 2 with an excess of alpha-lithiated methyl phenyl or dimethyl sulfones yielded 3a. The reaction of 2 with sterically unhindered lithiated alkyl sulfones gave mixtures of the respective olefination products 3b-d along with the Shapiro fragmentation product 4. Sterically hindered lithiated sulfones afforded Shapiro products exclusively. In contrast, aldehyde tosylhydrazones 2 or 6 in reactions with a variety of alpha-magnesio primary or secondary alkyl sulfones gave olefination products 3a-j and 7a-c in high yields (Tables 1 and 2). beta-Branched alkyl sulfones afforded predominantly (E)-alkenes, whereas unhindered primary sulfones gave mixtures of (E)- and (Z)-alkenes with low selectivity. Reaction of the 2,4,6-triisopropylbenzenesulfonylhydrazone (trisylhydrazone) of cyclodecanone 11c with alpha-magnesio methyl phenyl sulfone afforded the methylidene derivative 12a contaminated with the Shapiro product 13. Tosylhydrazone 2 resisted reaction with i-PrMgCl and gave only a small amount of the addition product in reaction with Bu(2)Mg. Some mechanistic aspects of the reaction of tosylhydrazones with organomagnesium compounds are discussed.

  17. 40 CFR 721.10045 - Diazotized substituted heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel...

    Science.gov (United States)

    2010-07-01

    ... coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (generic). 721.10045... derivative, nickel complex, alkaline salt (generic). (a) Chemical substance and significant new uses subject... heteromonocycle coupled with naphthalene sulfonic acid derivative, nickel complex, alkaline salt (PMN P-02-737) is...

  18. Post-sulfonation of cellulose nanofibrils with a one-step reaction to improve dispersibility.

    Science.gov (United States)

    Luo, Jeffrey; Semenikhin, Nikolay; Chang, Huibin; Moon, Robert J; Kumar, Satish

    2018-02-01

    Cellulose nanofibrils (CNF) were sulfonated and the dispersion quality was compared to unfunctionalized and 2,2,6,6-tetramethylpiperdine-1-oxyl radical (TEMPO) post-oxidation treatment of existing CNF (mechanically fibrillated pulp). A post-sulfonation treatment on existing CNF in chlorosulfonic acid and dimethylformamide (DMF) resulted in sulfonated CNF that retained a fibril-like morphology. There was a small decrease in the cellulose crystallinity index for the sulfonated CNF, but this was much lower than the reported regioselective oxidative bisulfite pretreatment method used to make sulfonated CNF. The current approach was extremely quick, and 5min of reaction time was sufficient to result in significant improvements in dispersibility compared to unfunctionalized CNF. The sulfonated CNF and TEMPO oxidized CNF had better dispersibility compared to the unfunctionalized CNF when dispersed in DMF and water, and in many cases the sulfonated CNF had better dispersibility than the TEMPO CNF. It was found that when CNF was dispersed in DMF the TEMPO CNF formed carboxyl dimethylammonium groups, while the sulfonated CNF formed formate groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Ionomeric membranes based on partially sulfonated poly(styrene) : synthesis, proton conduction and methanol permeation

    NARCIS (Netherlands)

    Picchioni, F.; Tricoli, V.; Carretta, N.

    2000-01-01

    Homogeneuosly sulfonated poly(styrene) (SPS) was prepared with various concentration of sulfonic acid groups in the base polymer. Membranes cast from these materials were investigated in relation to proton conductivity and methanol permeability in the temperature range from 20°C to 60°C. It was

  20. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Science.gov (United States)

    2010-07-01

    ..., alkali and amine salts. 721.2565 Section 721.2565 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and alkylated...

  1. Las denominaciones de las ocupaciones

    Directory of Open Access Journals (Sweden)

    Jesus Emilio Castañeda

    1990-04-01

    Full Text Available RESUMEN El propósito de este artículo, es mostrar al lector la forma como en nuestro ámbito existen diversos factores que han permitido la proliferación de maneras de llamar las ocupaciones. Aspectos regionales, la tradición, clases de organización, situaciones románticas, adjetivización de los cargos, peyorización  son entre otras razones que han generado  la creación de serie de sinónimos, de las ocupaciones, objeto de estudio de la sociologia del trabajo y de la administración de los recursos humanos.

  2. Radiation-chemical synthesis of polypropylene fabrics with sulfonic acid functional groups

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Hyun Kug; Park, Jung Soo; Han, Do Hung, E-mail: dhhan@yumail.ac.kr; Bondar, Iuliia, E-mail: juliavad@yahoo.co

    2011-04-01

    A sorption-active material carrying sulfonic acid groups was synthesized by the radiation-induced graft polymerization of styrene monomer onto the surface of non-woven polypropylene fabric, followed by sulfonation of the grafted polystyrene chains. The effect of the main experimental parameters (absorbed dose, monomer concentration, reaction time) on the styrene degree of grafting was investigated. The sulfonation process with 5% chlorosulfonic acid at room temperature was investigated in detail and the optimal sulfonation conditions for the samples with a medium degree of grafting (70-140%) were determined. Densities of 3.5-5 meq/g were obtained by applying those sorption-active PP fabrics with a sulfonic acid group.

  3. [Synthesis, solubility, lipids-lowering and liver-protection activities of sulfonated formononetin].

    Science.gov (United States)

    Wang, Qiu-ya; Meng, Qing-hua; Zhang, Zun-ting; Tian, Zhen-jun; Liu, Hui

    2009-04-01

    A water-soluble compound, sodium formononetin-3'-sulfonate with good lipid-lowering and liver-protection activities was synthesized. It was synthesized by sulfonation reaction, and its structure was characterized by IR, NMR and elemental analyses. The solubility of sodium formononetin-3'-sulfonate in water and n-octanol/water partition coefficient were determined by UV spectrophotometry. The lipid-lowering and liver-protection activities of sodium formononetin-3'-sulfonate were tested by using rat's high fat model induce by feeding with high fat food. The results showed that sodium formononetin-3'-sulfonate not only had favorable water, solubility but also had good lipid-lowering and liver-protection activities.

  4. New determination method for sulfonation degree of phthalic anhydride by RP-HPLC.

    Science.gov (United States)

    Zhu, Lijun; Song, Lechun; Liu, Bin; Zhou, Yulu; Xiang, Yuzhi; Xia, Daohong

    2014-01-01

    A novel method was developed to monitor the reaction process and evaluate the sulfonation level in the sulfonation of phthalic anhydride by reversed-phase high-performance liquid chromatography (RP-HPLC). The product peak was identified in chromatograms through product analysis and by comparing its retention time with that of standard compounds. By comparing the hydrolysis and alcoholysis methods, optimized pretreatment of the sample was found for RP-HPLC. Based on the determined percentages of phthalic anhydride and sulfonated phthalic anhydride in the mixture, the degree of sulfonation was calculated. When the sulfonation degree of phthalic anhydride was in the range of 2.8-71%, the recovery of 97-104% was achieved, and the procedure was rapid and accurate.

  5. Sulfonation and anticoagulant activity of botryosphaeran from Botryosphaeria rhodina MAMB-05 grown on fructose.

    Science.gov (United States)

    Mendes, Simone Ferreira; dos Santos, Osvaldo; Barbosa, Aneli M; Vasconcelos, Ana Flora D; Aranda-Selverio, Gabriel; Monteiro, Nilson K; Dekker, Robert F H; Sá Pereira, Mariana; Tovar, Ana Maria F; Mourão, Paulo A de Souza; da Silva, Maria de Lourdes Corradi

    2009-10-01

    Botryosphaeran (EPS(FRU)), an exopolysaccharide of the beta-(1-->3,1-->6)-d-glucan type with 31% branching at C-6, is produced by the fungus Botryosphaeria rhodina MAMB-05 when grown on fructose as carbon source. Botryosphaeran was derivatized by sulfonation to induce anticoagulant activity. The effectiveness of the sulfonation reaction by chlorosulfonic acid in pyridine was monitored by the degree of substitution and FT-IR analysis of the sulfonated EPS(FRU) (once sulfonated, EPS(FRUSULF); and re-sulfonated, EPS(FRURESULF)). Activated partial thromboplastin time (APTT) and thrombin time (TT) tests of EPS(FRURESULF) indicated significant in vitro anticoagulant activity that was dose-dependent. EPS(FRU) did not inhibit any of the coagulation tests.

  6. Sulfonation, an underexploited area: from skeletal development to infectious diseases and cancer.

    Science.gov (United States)

    Leung, Ada W. Y.; Backstrom, Ian; Bally, Marcel B

    2016-08-23

    Sulfonation is one of the most abundant cellular reactions modifying a wide range of xenobiotics as well as endogenous molecules which regulate important biological processes including blood clotting, formation of connective tissues, and functionality of secreted proteins, hormones, and signaling molecules. Sulfonation is ubiquitous in all tissues and widespread in nature (plants, animals, and microorganisms). Although sulfoconjugates were discovered over a century ago when, in 1875, Baumann isolated phenyl sulfate in the urine of a patient given phenol as an antiseptic, the significance of sulfonation and its roles in human diseases have been underappreciated until recent years. Here, we provide a current overview of the significance of sulfonation reactions in a variety of biological functions and medical conditions (with emphasis on cancer). We also discuss research areas that warrant further attention if we are to fully understand how deficiencies in sulfonation could impact human health which, in turn, could help define treatments to effect improvements in health.

  7. Las emociones y las TIC

    OpenAIRE

    Enríquez, Silvia Cecilia

    2014-01-01

    Tal vez este pueda resultar un tema sorprendente y, sin embargo, hay abundante bibliografía al respecto. Es posible que no nos lo hayamos planteado nunca, pero nuestra reacción ante el empleo de las TIC es determinante a la hora de medir los resultados que logremos en el aprendizaje que debemos hacer para poder incorporarlas a nuestra tarea. Docentes en Línea

  8. Nanostructured membranes and electrodes with sulfonic acid functionalized carbon nanotubes

    KAUST Repository

    Tripathi, Bijay Prakash

    2011-02-01

    Herein we report the covalent functionalization of multiwall carbon nanotubes by grafting sulfanilic acid and their dispersion into sulfonated poly(ether ether ketone). The nanocomposites were explored as an option for tuning the proton and electron conductivity, swelling, water and alcohol permeability aiming at nanostructured membranes and electrodes for application in alcohol or hydrogen fuel cells and other electrochemical devices. The nanocomposites were extensively characterized, by studying their physicochemical and electrochemical properties. They were processed as self-supporting films with high mechanical stability, proton conductivity of 4.47 × 10 -2 S cm-1 at 30 °C and 16.8 × 10-2 S cm-1 at 80 °C and 100% humidity level, electron conductivity much higher than for the plain polymer. The methanol permeability could be reduced to 1/20, keeping water permeability at reasonable values. The ratio of bound water also increases with increasing content of sulfonated filler, helping in keeping water in the polymer in conditions of low external humidity level. © 2010 Elsevier B.V.

  9. Sulfonated Poly(styrene) Chains Grafted on Magnetic Nanoparticles

    Science.gov (United States)

    Jiao, Yang; Yevelev, Anton; Parra, Javier; Akcora, Pinar; Stevens Institute of Technology Team

    2014-03-01

    Iron oxide nanoparticles functionalized with poly(styrene) (PS) chains at various grafting densities and loadings present stable and ordered nanostructures for tuning the mechanical and conductive properties in polymer composites. Strings, spherical and anisotropic clusters and well-dispersed particles are achieved with PS-grafted Fe3O4 nanoparticles in PS matrices upon varying the system parameters. In this work, we report the effect of sulfonic group locations on the aggregation state of polymer-grafted nanoparticles. Structures formed by the random and diblock copolymers of PS-poly(styrene sulfonate) (PSS) grafted particles will be discussed with small-angle x-ray scattering (SAXS) measurements in solution and melts. The conformational changes in PS-grafted chains and ion-containing grafts will be also presented in small-angle neutron-scattering (SANS) results to understand the role of polymer on the assembly of particles at the low grafting density. We acknowledge support by NSF-CAREER-DMR (#1048865).

  10. Polyaniline synthesized with functionalized sulfonic acids for blends manufacture

    Directory of Open Access Journals (Sweden)

    Mara Joelma Raupp Cardoso

    2007-12-01

    Full Text Available Polyaniline (PAni, an electronic conductive polymer, has poor mechanical properties, such as low tensile, compressive and flexural strength that render PAni a non-ideal material to be processed for practical applications. Desired properties of polyaniline can be enhanced by mixing it with a polymer that has good mechanical properties. In this work, PAni was synthesised using functionalized sulfonic acids like camphorsulfonic acid (CSA and dodecilbenzene sulfonic acid (DBSA in order to promote PAni doping and improve its solubility, making possible conductive blends manufacture. The different forms of PAni were characterized by infra-red spectroscopy, thermal analysis, scanning electron microscopy and conductivity measurements. A conductive blend composed of PAni/DBSA and lower density polyethylene (LDPE was obtained via solubilization method and its thermal, morphological and electrical properties were investigated. Concentrations as low as 5 wt. (% of PAni was able to lead to electrical conductivities of PAni/LDPE blends in the range of 10-3 S.cm-1, showing great potential to be used in antistatic packing, electromagnetic shielding, anti-corrosion shielding or as a semiconductor.

  11. Enhancing the phase segregation and connectivity of hydrophilic channels by blending highly sulfonated graft copolymers with fluorous homopolymers

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller; Ching-Ching Yang, Ami; Jankova Atanasova, Katja

    2013-01-01

    The influence of tuning the ionic content of membranes by blending, as opposed to varying the degree of sulfonation, is evaluated. Membranes of fully sulfonated poly(vinylidene fluoride-co-chlorotrifluoroethylene)-g-poly(styrene sulfonic acid) blended with PVDF were prepared and investigated...

  12. 40 CFR 417.100 - Applicability; description of the air-SO3 sulfation and sulfonation subcategory.

    Science.gov (United States)

    2010-07-01

    ...-SO3 sulfation and sulfonation subcategory. 417.100 Section 417.100 Protection of Environment... POINT SOURCE CATEGORY Air-SO3 Sulfation and Sulfonation Subcategory § 417.100 Applicability; description of the air—SO3 sulfation and sulfonation subcategory. The provisions of this subpart are applicable...

  13. 40 CFR 417.140 - Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

    Science.gov (United States)

    2010-07-01

    ... neutralization of sulfuric acid esters and sulfonic acids subcategory. 417.140 Section 417.140 Protection of... MANUFACTURING POINT SOURCE CATEGORY Neutralization of Sulfuric Acid Esters and Sulfonic Acids Subcategory § 417.140 Applicability; description of the neutralization of sulfuric acid esters and sulfonic acids...

  14. Biofilm behavior on sulfonated poly(ether-ether-ketone) (sPEEK)

    International Nuclear Information System (INIS)

    Montero, Juan F.D.; Tajiri, Henrique A.; Barra, Guilherme M.O.; Fredel, Márcio C.; Benfatti, Cesar A.M.; Magini, Ricardo S.; Pimenta, Andréa L.; Souza, Júlio C.M.

    2017-01-01

    Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFU mL −1 ) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5 h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p < 0.05) between 2 and 3 h sulfonation groups. A significant decrease (p < 0.05) in CFU mL −1 was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3 h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3 h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications. - Highlights: • PEEK can be dissolved to incorporate therapeutic compounds. • High sulfonation degree on sPEEK affected the biofilm growth. • The sulfonation degree must be controlled to maintain the properties of sPEEK.

  15. Effect of N-Sulfonation on the Colloidal and Liquid Crystal Behavior of Chitin Crystallites

    Science.gov (United States)

    Li; Revol; Marchessault

    1997-08-15

    Chitin crystallites were heterogeneously N-sulfonated in an aqueous medium using triethylamine/sulfur trioxide (TEA/SO3) or pyridine/sulfur trioxide. The extent of N-sulfonation of the crystallites has been controlled by the amount of TEA/SO3 added in the reaction. The concentration of sulfur in the crystallites after N-sulfonation was quantified using conductimetric titration and elemental analysis. The ratio of N-sulfonated amino groups to amino groups (S/N) was calculated based on the titration data. The presence of N-S bonds assumed to be at crystallite surfaces was demonstrated by X-ray photoelectron spectroscopy (XPS). After N-sulfonation, the crystallites have two ionizable groups at their surface: -NH3+ and -NHSO3H(Na). The former is pH dependent. The colloidal properties of the N-sulfonated crystallites having different S/N were investigated by plotting the zeta potential as a function of the pH of the suspension. The isoelectric point was found to change with the level of N-sulfonation. Transmission electron microscopy shows that the aggregation of crystallites depends strongly on the extent of N-sulfonation. Above a certain concentration, the original chitin crystallites form tactoids (chiral nematic domains) in an aqueous medium. This phenomenon was not observed for the crystallites with a low extent of surface N-sulfonation (below 70%). At about 80% N-sulfonation, the formation of tactoids was once again observed. Copyright 1997Academic Press

  16. Las Farmacodependencias

    Directory of Open Access Journals (Sweden)

    José Francisco Socarrás

    1994-09-01

    Full Text Available

    Ahora, cuando la Corte Constitucional ha despenalizado al farmacodependiente por el consumo de drogas, conviene informar sobre las consecuencias perjudiciales de estas. A quienes deseen un conocimiento detallado al respecto, les recomiendo documentarse en “Enciclopedia de Psiquiatría”, publicada por “El Ateneo” en Buenos Aires.

    El Capítulo respectivo es del doctor Daniel L. Murguia. El denominador corriente de su abuso es sencillamente la dependencia, nombre propuesto por la Organización Mundial de la Salud, definido como el “estado psíquico y a veces físico causado por la interacción entre un organismo vivo y un fármaco”. Su carácter esencial es el impulso psicofísico a consumir el producto en forma continua o periódica, con el fin de experimentar los efectos que acarrea y evitar los malestares de su privación. Todas las drogas del respectivo género, consumidas a dosis altas, tienen efectos psicotóxicos que alteran la conducta y en algunos casos conducen a la muerte.

    Los expertos de la Organización Mundial califican las mencionadas sustancias en seis grupos, a saber:

    1. Morfina y opiáceas, los cuales crean dependencia física y psicológica, con tolerancia precoz, necesidad de aumentar las dosis y síndrome de abstinencia bastante peligroso. Entre los derivados se cuentan los siguientes: Hidromorfina (Dilaudid; oximorfina (Nurmophan; heroína,
    éter diacético de la morfina (Diacetilmorfina; codeína (Metilmorfina; hidrocodeína (Hicadan’ oxicodeína (Perdocan. Los efectos de los opiáceo~ son los siguientes: analgesia, depresión respiratoria y espasmo gastrointestinal. Las dosis tóxicas pueden provocar convulsiones.

    2. Barbitúricos, alcohol y sedantes como el fenobarbital, que provocan así mismo dependencia física.

    3. Anfetaminas, en particular la Bencedrina inhalante, que acarrea dependencia psicológica.

    4. Cocaína, cuya dependencia psíquica es tal que muchos

  17. The influence of time reaction to characteristic of methyl ester sulfonate from seed oil ketapang

    Directory of Open Access Journals (Sweden)

    Poedji Loekitowati Hariani

    2016-02-01

    Full Text Available The aim of the present work was to The Preparation of Methyl Ester Sulfonate From Ketapang Seed Oil As Surfactant. The research is to determine the optimum condition synthesis of methyl ester sulfonate surfactant with reaction time variations (3.5; 4.0; 4.5; 5.0; 5.5 hours. The methyl ester from ketapang seed oil were analysis by GC-MS and identified methyl ester sulfonate by using FTIR spectroscopy. The methyl ester from ketapang seed oil showed containing of methyl palmitoleic, methyl linoleic, methyl palmitate, methyl stearate, methyl oleic, methyl palmitolenat and methyl eicosenoate. The optimum condition of methyl ester sulfonate at reaction time 4.5 hours with the mass of methyl ester sulfonate 34,85 g. For the FTIR spectra of sulfonate group is indicated by shifting of wave number at 1118.71cm-1 until 1029.1 cm-1. The characteristics of methyl ester sulfonate at the optimum reaction time have emulsion stability 71.684%, density 0.8714 g/mL, surface tension 36.232 dyne/cm, and maximum absorbance 1.428 at the maximum wavelength 660 nm.

  18. Celecoxib influences steroid sulfonation catalyzed by human recombinant sulfotransferase 2A1.

    Science.gov (United States)

    Ambadapadi, Sriram; Wang, Peter L; Palii, Sergiu P; James, Margaret O

    2015-08-01

    Celecoxib has been reported to switch the human SULT2A1-catalyzed sulfonation of 17β-estradiol (17β-E2) from the 3- to the 17-position. The effects of celecoxib on the sulfonation of selected steroids catalyzed by human SULT2A1 were assessed through in vitro and in silico studies. Celecoxib inhibited SULT2A1-catalyzed sulfonation of dehydroepiandrosterone (DHEA), androst-5-ene-3β, 17β-diol (AD), testosterone (T) and epitestosterone (Epi-T) in a concentration-dependent manner. Low μM concentrations of celecoxib strikingly enhanced the formation of the 17-sulfates of 6-dehydroestradiol (6D-E2), 17β-dihydroequilenin (17β-Eqn), 17β-dihydroequilin (17β-Eq), and 9-dehydroestradiol (9D-E2) as well as the overall rate of sulfonation. For 6D-E2, 9D-E2 and 17β-Eqn, celecoxib inhibited 3-sulfonation, however 3-sulfonation of 17β-Eq was stimulated at celecoxib concentrations below 40 μM. Ligand docking studies in silico suggest that celecoxib binds in the substrate-binding site of SULT2A1 in a manner that prohibits the usual binding of substrates but facilitates, for appropriately shaped substrates, a binding mode that favors 17-sulfonation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Andrographolide sulfonate ameliorates experimental colitis in mice by inhibiting Th1/Th17 response.

    Science.gov (United States)

    Liu, Wen; Guo, Wenjie; Guo, Lele; Gu, Yanhong; Cai, Peifen; Xie, Ning; Yang, Xiaoling; Shu, Yongqian; Wu, Xuefeng; Sun, Yang; Xu, Qiang

    2014-06-01

    Inflammatory bowel disease (IBD) is a chronic, relapsing and remitting condition of inflammation involves overproduction of pro-inflammatory cytokines and excessive functions of inflammatory cells. However, current treatments for IBD may have potential adverse effects including steroid dependence, infections and lymphoma. Therefore new therapies for the treatment of IBD are desperately needed. In the present study, we aimed to examine the effect of andrographolide sulfonate, a water-soluble form of andrographolide (trade name: Xi-Yan-Ping Injection), on murine experimental colitis induced by 2, 4, 6-trinitrobenzene sulfonic acid (TNBS). Andrographolide sulfonate was administrated through intraperitoneal injection to mice with TNBS-induced colitis. TNBS-induced body weight loss, myeloperoxidase activity, shortening of the colon and colonic inflammation were significantly ameliorated by andrographolide sulfonate. Both the mRNA and protein levels of pro-inflammatory cytokines were reduced by andrographolide sulfonate administration. Moreover, andrographolide sulfonate markedly suppressed the activation of p38 mitogen-activated protein kinase as well as p65 subunit of nuclear factor-κB (NF-κB). Furthermore, CD4(+) T cell infiltration as well as the differentiation of Th1 (CD4(+)IFN-γ(+)) and Th17 (CD4(+)IL17A(+)) subset were inhibited by andrographolide sulfonate. In summary, these results suggest that andrographolide sulfonate ameliorated TNBS-induced colitis in mice through inhibiting Th1/Th17 response. Our study shows that water-soluble andrographolide sulfonate may represent a new therapeutic approach for treating gastrointestinal inflammatory disorders. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Radiation-induced crosslinking of poly(styrene–butadiene–styrene) block copolymers and their sulfonation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sun-Young [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Song, Ju-Myung; Sohn, Joon-Yong [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of); Shul, Yong-Gun [Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Shin, Junhwa, E-mail: shinj@kaeri.re.kr [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 29 Geumgu-gil, Jeongeup-si, Jeollabuk-do 580-185 (Korea, Republic of)

    2013-12-01

    Highlights: • The c-SBS films were prepared using a gamma ray or electron beam. • The crosslinking degree of the c-SBS films were increased with the irradiation dose. • The prepared c-SBS films were sulfonated with various concentration of CSA. • The sulfonation of the c-SBS film is largely dependent on the concentration of CSA. • The sulfonation process is progressed from the surface to the inner part of c-SBS film. -- Abstract: Several crosslinked poly(styrene–butadiene–styrene) (c-SBS) block copolymer films were prepared using a gamma ray or electron beam with various irradiation doses and the prepared c-SBS film was then subjected to sulfonation using a chlorosulfonic acid (CSA) solution to introduce a sulfonic acid group. To estimate the degree of crosslinking, the gel fractions and FT-IR spectra of the c-SBS films were used and the results indicate that the degree of crosslinking is increased with an increase in the radiation dose. The surface morphology and mechanical property of the c-SBS films were observed using SEM and UTM instruments, respectively. The sulfonated c-SBS films were investigated by measuring the ion exchange capacity (IEC) and by observing the cross-sectional distribution patterns of sulfonic acid group using an SEM-EDX instrument. The IEC and SEM-EDX studies indicate that the sulfonated c-SBS membranes can be successfully prepared through the radiation crosslinking of the SBS film and the subsequent sulfonation with a diluted CSA solution.

  1. Polyvinyl Alcohol-Sulfonated Polyethersulfone Blend for Application in Proton-Exchange Membranes

    Directory of Open Access Journals (Sweden)

    Fatemeh Askari

    2016-11-01

    Full Text Available In recent years, proton-exchange membranes as the main components of composite actuators have been paid special attention because of their important role in membrane technology. Polyvinyl alcohol was blended with sulfonated polyethersulfone in the presence of glutaraldehyde as crosslinking agent. The effect of the blend ratio and glutaraldehyde content on the ionic and mechanical properties of the blend was studied. For this purpose, polyethersulfone was sulfonated by chlorosulfonic acid. The sulfonated sample was blended with polyvinyl alcohol in different ratios, and in order to control the water uptake of polyvinyl alcohol, glutaraldehyde was added into the blend mixture. Degree of sulfonation of polyethersulfone measured by titration method was found to be 26%. By increasing the sulfonated polyethersulfone and glutaraldehyde contents, the water uptake of membranes indicated a decreasing trend with a minimum of 18%. The higher glutaraldehyde/polyvinyl alcohol (GA/PVA ratio from 0.03 to 0.06 had not much effect on the ion exchange capacity but reduced its proton conductivity. With increasing the sulfonated polyethersulfone/polyvinyl alcohol (SPES/PVA ratio, the sulfonic acid groups were increased, and therefore, the ion exchange capacity and proton conductivity were both increased to their maximum values of 0.62 meq/g and 2.63 mS/cm. Tensile test results showed that the blend containing 70% sulfonated polyethersulfone with the GA/PVA ratio of 0.06, had the maximum mechanical strength and young modulus of 30.86 and 104.18 MPa, respectively. Besides, each membrane showed a tougher behavior when the sulfonated polyethersulfone content was increased.

  2. Benzyl-tributyl-ammonium 4-hydroxy-naphthalene-2-sulfonate.

    Science.gov (United States)

    Uta, Kazuya; Mizuguchi, Jin

    2009-01-17

    The title compound, C(19)H(34)N(+)·C(10)H(7)O(4)S(-), is a charge-control agent used for toners in electrophotography. In the crystal structure, centrosymmetric anions associate through O-H⋯O hydrogen bonds formed between the O-H group of one anion and the sulfonate O atom of a neighbor. The components of the dimer are offset with respect to each other so that the separation between the two parallel naphthalene skeletons is about 1.6 Å. The ethyl residues of two of the butyl groups are disordered and were modelled over two postions (site occupancies = 0.33/0.67 and 0.34/0.66).

  3. Characteristics of polyaniline electropolymerized in camphor sulfonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Santos, J.R. Jr. [Instituto de Quimica de Sao Carlos/DFQ/USP, C.P. 369, 13560-970, Sao Carlos, SP (Brazil); Malmonge, J.A. [Instituto de Fisica de Sao Carlos/DFCM/USP, C.P. 369, 13560-970, Sao Carlos, SP (Brazil); Conceicao Silva, A.J.G. [Instituto de Fisica de Sao Carlos/DFCM/USP, C.P. 369, 13560-970, Sao Carlos, SP (Brazil); Motheo, A.J. [Instituto de Quimica de Sao Carlos/DFQ/USP, C.P. 369, 13560-970, Sao Carlos, SP (Brazil); Mascarenhas, Y.P. [Instituto de Fisica de Sao Carlos/DFCM/USP, C.P. 369, 13560-970, Sao Carlos, SP (Brazil); Mattoso, L.H.C. [Instituto de Fisica de Sao Carlos/DFCM/USP, C.P. 369, 13560-970, Sao Carlos, SP (Brazil)

    1995-03-01

    Polyaniline was electropolymerized by cyclic voltammetry in the presence of camphor sulfonic acid (CSA), and the resulting film was characterized by solubility tests, UV-Vis absorption, electron microscopy, X-ray diffraction and conductivity measurements. The use of the functionalized acid - CSA - made it possible to obtain the as-electropolymerized polymer (in the doped state) soluble in organic solvents such as m-cresol and chloroform. The UV-Vis spectra of PAni-CSA in m-cresol presented a free-carrier tail commencing at 1000nm which may be attributed to secondary doping due to conformational changes of the polymer chains. After treatment with m-cresol the film exhibited an increase of conductivity reaching ca. 100S/cm. (orig.)

  4. A pair of sulfonated diarylheptanoid epimers from Kaempferia galanga.

    Science.gov (United States)

    Wang, Fang-Lin; Luo, Jian-Guang; Wang, Xiao-Bing; Kong, Ling-Yi

    2013-03-01

    To discover new bioactive constituents from Kaempferia galanga L. (Zingiberaceae). The extract of K. galanga was divided into the chloroform and water-soluble portions. The latter fraction was successively subjected to column chromatography over a D101 macroporous adsorption resin, MCI, Sephadex LH-20, and preparative HPLC to obtain two compounds. Two novel sulfonated diarylheptanoid epimers, namely kaempsulfonic acids A (1) and B (2), were isolated from the rhizomes of K. galanga. Their structures were established by analysis of spectroscopic data. The absolute configurations of 1 and 2 were determined by the comparison of experimental electronic circular dichroism (ECD) spectroscopy and the computational calculation method, combined with Mo2(OAc)4 induced circular dichroism (ICD). The isolates 1 and 2 are new compounds and their absolute configurations were determined for the first time. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  5. Electronic Conductivity of Polypyrrole−Dodecyl Benzene Sulfonate Complexes

    DEFF Research Database (Denmark)

    West, Keld; Bay, Lasse; Nielsen, Martin Meedom

    2004-01-01

    and therefore smaller hopping distances. This was supported by X-ray measurements. Synthesis at lower temperatures generally leads to higher conductivity. The conductivity is strongly dependent on the potential, being more than four magnitudes smaller for the reduced state where the number of electronic......The electronic conductivity of the electroactive polymer polypyrrole-dodecyl benzene sulfonate (PPy-DBS) has been characterized as function of the redox level. The polymer was synthesized with different isomers of the dopant anions: the common mixed DBS tenside and three well-defined synthetic....... These investigations demonstrate that even minor differences in the dopant anion can cause significant changes in the physical properties of the electroactive polymer. The highest conductivities ($sigma$-25$/ = 39 Scm$+-1$/) are obtained by the (6D)BS isomer, perhaps because the branching leads to denser packing...

  6. Poly (ether imide sulfone) membranes from solutions in ionic liquids

    KAUST Repository

    Kim, Dooli

    2017-11-20

    A membrane manufacture method based on non-volatile solvents and a high performance polymer, poly (ether imide sulfone) (EXTEM™), is proposed, as greener alternative to currently industrial process. We dissolved EXTEM™ in pure ionic liquids: 1-ethyl-3-methylimidalzolium thiocyanate ([EMIM]SCN), 1-butyl-3-methylimidalzolium thiocyanate ([BMIM]SCN), and 1-ethyl-3-methylimidalzolium acetate ([EMIM]OAc). The following polymer solution parameters were evaluated to optimize the manufacture: Gibbs free energy of mixing (G), intrinsic viscosity ([]) and hydrodynamic diameter. Membranes with sponge-like structure and narrow pore size distribution were obtained from solutions in [EMIM]SCN. They were tested for separation of proteins and deoxyribonucleic acids (DNA). Due to the polymer stability, we foresee that applications in more demanding chemical separations would be possible. [EMIM]SCN was 96 % purified and recovered after the membrane fabrication, contributing to the sustainability of the whole manufacturing process.

  7. Aromatic sulfonation with sulfur trioxide: mechanism and kinetic model.

    Science.gov (United States)

    Moors, Samuel L C; Deraet, Xavier; Van Assche, Guy; Geerlings, Paul; De Proft, Frank

    2017-01-01

    Electrophilic aromatic sulfonation of benzene with sulfur trioxide is studied with ab initio molecular dynamics simulations in gas phase, and in explicit noncomplexing (CCl 3 F) and complexing (CH 3 NO 2 ) solvent models. We investigate different possible reaction pathways, the number of SO 3 molecules participating in the reaction, and the influence of the solvent. Our simulations confirm the existence of a low-energy concerted pathway with formation of a cyclic transition state with two SO 3 molecules. Based on the simulation results, we propose a sequence of elementary reaction steps and a kinetic model compatible with experimental data. Furthermore, a new alternative reaction pathway is proposed in complexing solvent, involving two SO 3 and one CH 3 NO 2 .

  8. Sulfonated copolyimide membranes derived from a novel diamine monomer with pendant benzimidazole groups for fuel cells

    DEFF Research Database (Denmark)

    Li, Wei; Guo, Xiaoxia; Aili, David

    2015-01-01

    Sulfonated polyimides are among the most interesting proton exchange membrane materials with high proton conductivity and good mechanical characteristics. As a major challenge the hydrolytic instability of the polymer backbone is addressed by introducing basic moieties in the polymer main chain....... A series of sulfonated copolyimides (SPI) are prepared via random copolymerizatio of 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA) with a new diamine monomer with pendant benzimidazole groups, 2,2'-bis(4-(1H-benzo[d]imidazol-2-yl)phenoxy)benzidine (BIPOB), and a sulfonated diamine monomer 4,4'-bis...

  9. Degradation and contamination of perfluorinated sulfonic acid membrane due to swelling-dehydration cycles

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Morgen, Per; Skou, Eivind Morten

    Formation of sulfonic anhydride S-O-S (from the condensation of sulfonic acids) was known one of the important degradation mechanisms [i] for Nafion membrane under hydrothermal aging condition, which is especially critical for hydrogen fuel cells. Similar mechanism would also have be desirable...... to the membrane degradation in direct methanol fuel cells (DMFCs), where liquid water has direct contact with the electrolyte. An ex-situ experiment was established with swelling-dehydration cycles on the membrane. However, formation of sulfonic anhydride was not detected during the entire treatment; instead...

  10. Derivatives of phenyl tribromomethyl sulfone as novel compounds with potential pesticidal activity

    Directory of Open Access Journals (Sweden)

    Krzysztof M. Borys

    2012-02-01

    Full Text Available A halogenmethylsulfonyl moiety is incorporated in numerous active herbicides and fungicides. The synthesis of tribromomethyl phenyl sulfone derivatives as novel potential pesticides is reported. The title sulfone was obtained by following three different synthetic routes, starting from 4-chlorothiophenol or 4-halogenphenyl methyl sulfone. Products of its subsequent nitration were subjected to the SNAr reactions with ammonia, amines, hydrazines and phenolates to give 2-nitroaniline, 2-nitrophenylhydrazine and diphenyl ether derivatives. Reduction of the nitro group of 4-tribromomethylsulfonyl-2-nitroaniline yielded the corresponding o-phenylenediamine substrate for preparation of structurally varied benzimidazoles.

  11. Celecoxib influences steroid sulfonation catalyzed by human recombinant sulfotransferase 2A1

    OpenAIRE

    Ambadapadi, Sriram; Wang, Peter L.; Palii, Sergiu P.; James, Margaret O.

    2015-01-01

    Celecoxib has been reported to switch the human SULT2A1-catalyzed sulfonation of 17βestradiol (17β-E2) from the 3- to the 17-position. The effects of celecoxib on the sulfonation of selected steroids catalyzed by human SULT2A1 were assessed through in vitro and in silico studies. Celecoxib inhibited SULT2A1-catalyzed sulfonation of dehydroepiandrosterone (DHEA), androst-5-ene-3β, 17β-diol (AD), testosterone (T) and epitestosterone (Epi-T) in a concentration-dependent manner. Low μM concentrat...

  12. Experiment and simulation studies on SPEEK PEM with different sulfonation degrees

    Science.gov (United States)

    Wang, Rujie; Li, Ming

    2017-04-01

    Effects of degrees of sulfonation (DS) on the cluster aggregation, proton conductivity and mechanical properties of sulfonated poly ether ether ketone (SPEEK) proton exchange membranes (PEMs) were investigated by experiment and simulation studies. SPEEK materials with different DS and the corresponding PEMs had been prepared by sulfonation and solution casting. The water uptake, swelling ratio, proton conductivity and mechanical properties of SPEEK PEMs were greatly affected by DS. And the hydrophilic cluster aggregation in SPEEK of different DS was revealed by molecular simulation. The relationship between structure and performance of SPEEK membrane provides theoretical guidance for the preparation of high performance proton exchange membranes.

  13. Synthesis of linear alkylbenzene sulphonate intercalated iron(II) iron(III) hydroxide sulphate (green rust) and adsorption of carbon tetrachloride

    DEFF Research Database (Denmark)

    Ayala Luis, Karina Barbara; Kaldor, D.K.; Bender Koch, Christian

    2007-01-01

    Green rusts, GRs, can act as both sorbents and reductants towards selected pollutants. Organo-GRs are expected to combine these properties with a high affinity for hydrophobic substances. A novel organo-GR, GRLAS, was synthesized by incorporating a mixture of linear alkylbenzenesulphonates (LAS...... was well ordered, although a mixture of surfactant was used for intercalation. The basal spacings of the GRLAS and the kinetics of the ion-exchange process were dependent on the initial surfactant loading; basal spacings of ~2.85 nm were obtained at The ratio LAS solution concentrations >10 mM. LASadsorbed...

  14. Stereocontrolled glycoside synthesis by activation of glycosyl sulfone donors with scandium(iii) triflate.

    Science.gov (United States)

    Xolin, Amandine; Losa, Romain; Kaid, Aicha; Tresse, Cédric; Beau, Jean-Marie; Boyer, François-Didier; Norsikian, Stéphanie

    2018-01-03

    The activation of aryl glycosyl sulfone donors has been achieved using scandium(iii) triflate and has led to the selective preparation of α-mannosides resulting from a post-glycosylation anomerization.

  15. REVISITING NUCLEOPHILIC SUBSTITUTION REACTIONS: MICROWAVE-ASSISTED SYNTHESIS OF AZIDES, THIOCYANATES AND SULFONES IN AQUEOUS MEDIUM

    Science.gov (United States)

    A practical, rapid and efficient microwave (MW) promoted synthesis of various azides, thiocyanates and sulfones, is described in aqueous medium. This general and expeditious MW-enhanced nucleophilic substitution approach uses easily accessible starting materials such as halides o...

  16. Derivatization of enolic OH of piroxicam: a comparative study on esters and sulfonates

    International Nuclear Information System (INIS)

    Jayaselli, J.; Cheemala, J. Manila Sagar; Geetha Rani, D.P.; Pal, Sarbani

    2008-01-01

    A number of ester and sulfonate derivatives of piroxicam were prepared via acylation/sulfonation of the enolic OH of piroxicam. All the compounds were evaluated for their chemical stability and cyclooxygenase inhibiting properties. Data suggested that esters could be useful for the development of potential prodrugs. The sulfonate derivatives prepared for the first time were found to be stable. One of them showed a moderately selective COX-2 inhibition over COX-1 and would have lower gastrointestinal side effects than piroxicam due to the masked enolic OH group. A plausible mechanism for the acylation/sulfonation process has been proposed that involves participation of the pyridine moiety of piroxicam. Molecular structure of one of the ester was established for the first time by the crystal structure analysis from X-ray powder data. (author)

  17. Derivatization of enolic OH of piroxicam: a comparative study on esters and sulfonates

    Energy Technology Data Exchange (ETDEWEB)

    Jayaselli, J.; Cheemala, J. Manila Sagar; Geetha Rani, D.P.; Pal, Sarbani [MNR Post Graduate College, Kukatpally, Hyderabad (India). Dept. of Chemistry]. E-mail: sarbani277@yahoo.com

    2008-07-01

    A number of ester and sulfonate derivatives of piroxicam were prepared via acylation/sulfonation of the enolic OH of piroxicam. All the compounds were evaluated for their chemical stability and cyclooxygenase inhibiting properties. Data suggested that esters could be useful for the development of potential prodrugs. The sulfonate derivatives prepared for the first time were found to be stable. One of them showed a moderately selective COX-2 inhibition over COX-1 and would have lower gastrointestinal side effects than piroxicam due to the masked enolic OH group. A plausible mechanism for the acylation/sulfonation process has been proposed that involves participation of the pyridine moiety of piroxicam. Molecular structure of one of the ester was established for the first time by the crystal structure analysis from X-ray powder data. (author)

  18. Preparation of a Sulfonated Carbonaceous Material from Lignosulfonate and Its Usefulness as an Esterification Catalyst

    Directory of Open Access Journals (Sweden)

    Duckhee Lee

    2013-07-01

    Full Text Available Sulfonated carbonaceous material useful as a solid acid catalyst was prepared from lignosulfonate, a waste of the paper-making industry sulfite pulping process, and characterized by 13C-NMR, FT-IR, TGA, SEM and elemental analysis, etc. The sulfonic acid group density and total density of all acid groups in the sulfonated carbonaceous material was determined by titration to be 1.24 mmol/g and 5.90 mmol/g, respectively. Its catalytic activity in the esterification of cyclohexanecarboxylic acid with anhydrous ethanol was shown to be comparable to that of the ionic exchange resin Amberlyst-15, when they were used in the same amount. In the meantime, the sulfonic acid group was found to be leached out by 26%–29% after it was exposed to hot water (95 °C for 5 h. The catalytic usefulness of the prepared carbonaceous material was investigated by performing esterifications.

  19. Effect of sulfonation and diethanolamine addition on the mechanical and physicochemical properties of SEPS copolymer

    Science.gov (United States)

    Patiño, D.; Correa, E.; Acevedo-Morantes, M.

    2016-02-01

    Modification techniques have been developed to achieve changes in the processing of polymers, and modification of their mechanical, thermal and morphological properties, as well as their hydrophobicity and conductivity. Sulfonation improves ion conductivity, antistatic behaviour, hydrophilicity and solubility of the polymers. These characteristics are related to the presence of sulfonic groups in the polymer matrix. This research project focuses on the evaluation of mechanical, physical and chemical properties of membranes that are based on a sulfonated Styrene-Ethylene-Propylene-Styrene (SEPS) copolymer. The membranes were functionalized with diethanolamine at 5, 15 and 30% w/w, to separate carbon dioxide. FTIR and XRD analyses were used to characterize the membranes. The sulfonated-loaded membrane with 15% of diethanolamine showed the best results in each characterization.

  20. Viscoelastic and Transport Properties of Sulfonated PS-PIB-PS Block Copolymers

    National Research Council Canada - National Science Library

    Napadensky, Eugene

    2001-01-01

    .... Small-angle x-ray scattering (SAXS) results confirmed that at a certain percent of sulfonation, a phase transition occurs from hexagonally packed cylinders to lamellar structure due to swelling of the styrene domains caused...

  1. A Modular Synthetic Approach to Isosteric Sulfonic Acid Analogues of the Anticoagulant Pentasaccharide Idraparinux

    Directory of Open Access Journals (Sweden)

    Erika Mező

    2016-11-01

    Full Text Available Heparin-based anticoagulants are drugs of choice in the therapy and prophylaxis of thromboembolic diseases. Idraparinux is a synthetic anticoagulant pentasaccharide based on the heparin antithrombin-binding domain. In the frame of our ongoing research aimed at the synthesis of sulfonic acid-containing heparinoid anticoagulants, we elaborated a modular pathway to obtain a series of idraparinux-analogue pentasaccharides bearing one or two primary sulfonic acid moieties. Five protected pentasaccharides with different C-sulfonation patterns were prepared by two subsequent glycosylation reactions, respectively, using two monosaccharide and four disaccharide building blocks. Transformation of the protected derivatives into the fully O-sulfated, O-methylated sulfonic acid end-products was also studied.

  2. Evaluation of Sulfonate-Based Collectors with Different Hydrophobic Tails for Flotation of Fluorite

    OpenAIRE

    Renji Zheng; Zijie Ren; Huimin Gao; Yupeng Qian

    2018-01-01

    This investigation aims to demonstrate the effects of hydrophobic tails on the affinity and relevant flotation response of sulfonate-based collectors for fluorite. For this purpose, a series of alkyl sulfonates with different hydrophobic tails, namely sodium decanesulfonate (C10), sodium dodecylsulfate (C12), sodium hexadecanesulfonate (C16), and sodium dodecylbenzenesulfonate (C12B) were applied. The flotation tests showed that C12 and C12B had a better collecting performance than C10 and C1...

  3. Las redes sociales presentes en las bibliotecas

    Directory of Open Access Journals (Sweden)

    Magda Cecilia Sandí S.

    2012-01-01

    Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  4. Las redes sociales presentes en las bibliotecas

    Directory of Open Access Journals (Sweden)

    Magda Cecilia Sandí Sandí

    2012-07-01

    Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  5. Las redes sociales presentes en las bibliotecas

    OpenAIRE

    Magda Cecilia Sandí Sandí

    2012-01-01

    El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

  6. Influence of LAS on marine calanoid copepod population dynamics and potential reproduction

    DEFF Research Database (Denmark)

    Christoffersen, Kirsten; Hansen, Benni Winding; Johansson, Liselotte Sander

    2003-01-01

    The toxicity of linear alkyl benzene sulfonate (LAS) to marine invertebrates is well documented under laboratory conditions using single-species tests. It is less known how LAS affects natural populations of aquatic organisms. We hypothesised that LAS was more toxic to the calanoid copepod Acartia...... were also investigated under in situ conditions. A series of seven mesocosms (holding approx. 3 m(3) of seawater each) was established with two mesocosms being controls without LAS and five mesocosms with increasing concentrations of LAS ranging from 0.1 to 6.5 mg l(-1) applied as a single dose....... The increased sensitivity under in situ conditions was probably promoted by the suboptimal growth conditions, e.g. no saturated food concentration or inadequate nutritive values of the food. The amount of food expressed as chlorophyll concentration was low (around 2 microg chl. a l(-1)) but was not affected...

  7. Sulfonated Polyimide-Clay Thin Films for Energy Application.

    Science.gov (United States)

    Ali, Farman; Saeed, Shaukat; Shah, Syed Sakhawat; Rahim, Fazal; Duclaux, Laurent; Levêque, Jean-Marc; Reinert, Laurence

    2016-01-01

    Sulfonated polyimides (SPIs) are considered as the promising alternatives to Nafion as membrane materials for the polymer electrolyte membrane (PEM). They generally exhibit high ionic conductivity, good mechanical properties, excellent thermal and chemical stabilities. The six-membered ring, naphthalenic anhydride-based SPIs, not only exhibit superior chemical and thermo-oxidative stabilities but are also more resistant to hydrolysis than their five-membered phthalic anhydride-based SPIs. The composites based on napthalenic polyimides are also significantly stable in high temperature environment and show better stability to hydrolysis. Incorporation of inorganic fillers into organic polymers has gained tremendous attention and these new materials are called organic-inorganic hybrids. Few patents related to the synthesis and performance PEM materials have been reviewed and cited. Keeping in view the importance of sulfonated polyimide based nanocomposites as potential membrane materials for PEM in fuel cell, we have synthesized SPIs clay based nanocomposite as potential membrane material. The objective of this work was to synthesize clay based SPIs thin films which could be used as membrane materials in PEM fuel cell for energy applications. Methods/Experimental: At the first step the nanometric sheets of vermiculite clay prepared via sonication was surface modified by grafting 3-APTES. Then the SPI was synthesized via one-step high temperature direct imidization method, which serve as a matrix material. The organo modified VMT was dispersed via sonication in the SPI matrix. Four different sets of organic-inorganic nanocomposite membranes thin films, having VMT contents in the range of 1 to 7 wt.% were prepared by casting, curing and acidification route. The synthesis of SPIs clay based thin films were carried out at three different steps and fully characterized. The synthesis of SPIs and SPIs clay based thin films were analyzed via different analytical techniques

  8. Composite proton exchange membrane based on sulfonated organic nanoparticles

    Science.gov (United States)

    Pitia, Emmanuel Sokiri

    As the world sets its sight into the future, energy remains a great challenge. Proton exchange membrane (PEM) fuel cell is part of the solution to the energy challenge because of its high efficiency and diverse application. The purpose of the PEM is to provide a path for proton transport and to prevent direct mixing of hydrogen and oxygen at the anode and the cathode, respectively. Hence, PEMs must have good proton conductivity, excellent chemical stability, and mechanical durability. The current state-of-the-art PEM is a perfluorosulfonate ionomer, Nafion®. Although Nafion® has many desirable properties, it has high methanol crossover and it is expensive. The objective of this research was to develop a cost effective two-phase, composite PEM wherein a dispersed conductive organic phase preferentially aligned in the transport direction controls proton transport, and a continuous hydrophobic phase provides mechanical durability to the PEM. The hypothesis that was driving this research was that one might expect better dispersion, higher surface to volume ratio and improved proton conductivity of a composite membrane if the dispersed particles were nanometer in size and had high ion exchange capacity (IEC, = [mmol sulfonic acid]/gram of polymer). In view of this, considerable efforts were employed in the synthesis of high IEC organic nanoparticles and fabrication of a composite membrane with controlled microstructure. High IEC, ~ 4.5 meq/g (in acid form, theoretical limit is 5.4 meq/g) nanoparticles were achieved by emulsion copolymerization of a quaternary alkyl ammonium (QAA) neutralized-sulfonated styrene (QAA-SS), styrene, and divinylbenzene (DVB). The effects of varying the counterion of the sulfonated styrene (SS) monomer (alkali metal and QAA cations), SS concentration, and the addition of a crosslinking agent (DVB) on the ability to stabilize the nanoparticles to higher IECs were assessed. The nanoparticles were ion exchanged to acid form. The extent of ion

  9. Water and Salt Transport Properties of Triptycene-Containing Sulfonated Polysulfone Materials for Desalination Membrane Applications.

    Science.gov (United States)

    Luo, Hongxi; Aboki, Joseph; Ji, Yuanyuan; Guo, Ruilan; Geise, Geoffrey M

    2018-01-31

    A series of triptycene-containing sulfonated polysulfone (TRP-BP) materials was prepared via condensation polymerization, and the desalination membrane-relevant fundamental water and salt transport properties (i.e., sorption, diffusion, and permeability coefficients) of the polymers were characterized. Incorporating triptycene into sulfonated polysulfone increased the water content of the material compared to sulfonated polysulfone materials that do not contain triptycene. No significant difference in salt sorption was observed between TRP-BP membranes and other sulfonated polysulfone membranes, suggesting that the presence of triptycene in the polymer did not dramatically affect thermodynamic interactions between salt and the polymer. Both water and salt diffusion coefficients in the TRP-BP membranes were suppressed relative to other sulfonated polysulfone materials with comparable water content, and these phenomena may result from the influence of triptycene on polymer chain packing and/or free-volume distribution, which could increase the tortuosity of the transport pathways in the polymers. Enhanced water/salt diffusivity selectivity was observed for some of the TRP-BP membranes relative to those materials that did not contain triptycene, and correspondingly, incorporation of triptycene into sulfonated polysulfone resulted in an increase, particularly for acid counterion form TRP-BP materials, in water/salt permeability selectivity, which is favorable for desalination membrane applications.

  10. Sulfonation and anticoagulant activity of fungal exocellular β-(1→6)-D-glucan (lasiodiplodan).

    Science.gov (United States)

    Vasconcelos, Ana Flora D; Dekker, Robert F H; Barbosa, Aneli M; Carbonero, Elaine R; Silveira, Joana L M; Glauser, Bianca; Pereira, Mariana Sá; Corradi da Silva, Maria de Lourdes

    2013-02-15

    An exocellular β-(1→6)-D-glucan (lasiodiplodan) produced by a strain of Lasiodiplodia theobromae (MMLR) grown on sucrose was derivatized by sulfonation to promote anticoagulant activity. The structural features of the sulfonated β-(1→6)-D-glucan were investigated by UV-vis, FT-IR and (13)C NMR spectroscopy, and the anticoagulant activity was investigated by the classical coagulation assays APTT, PT and TT using heparin as standard. The content of sulfur and degree of substitution of the sulfonated glucan was 11.73% and 0.95, respectively. UV spectroscopy showed a band at 261 nm due to the unsaturated bond formed in the sulfonation reaction. Results of FT-IR and (13)C NMR indicated that sulfonyl groups were inserted on the polysaccharide. The sulfonated β-(1→6)-D-glucan presented anticoagulant activity as demonstrated by the increase in dose dependence of APTT and TT, and these actions most likely occurred because of the inserted sulfonate groups on the polysaccharide. The lasiodiplodan did not inhibit the coagulation tests. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Enhancement of nanofibrillation of softwood cellulosic fibers by oxidation and sulfonation.

    Science.gov (United States)

    Pan, Shaobo; Ragauskas, Arthur J

    2014-10-13

    In this study, sulfonic acid groups were introduced to milled softwood (SW) bleached kraft fibers by oxidation and sulfonation with sodium periodate followed by sodium bisulfite under relatively mild conditions. The effect of variable amount of sulfonated groups on nanofibrillation of sulfonated cellulose samples was investigated. The cellulose samples, with contents of sulfonated groups of 371-501 μmol/g, were readily nanofibrillated by homogenization at relatively low pressure. These samples converted to viscous and transparent gels without clogging the homogenizer. By passing through the homogenizer one to four times, the transmittances of homogenized suspensions were up to 98%. SEM characterization of the homogenized and lyophilized fibril suspension indicates that the nanofibrillated fibrils are a network structure with lateral sizes of ∼ 15-45 nm and lengths ˃ 1 μm. The consecutive periodate oxidation and sulfonation with bisulfite was shown to be an effective pretreatment method to facilitate the nanofibrillation of softwood pulp cellulose and can be expectedly used with other cellulosic resources. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Thermoanalytical Investigation of Some Sulfone-Containing Drugs

    Directory of Open Access Journals (Sweden)

    Nahla N. Salama

    2012-01-01

    Full Text Available The thermal behavior of some sulfone-containing drugs, namely, dapsone (DDS, dimethylsulfone (MSM, and topiramate (TOP in drug substances, and products were investigated using different thermal techniques. These include thermogravimetry (TGA, derivative thermogravimetry (DTG, differential thermal analysis (DTA, and differential scanning calorimetry (DSC. The thermogravimetric data allowed the determination of the kinetic parameters: activation energy (Ea, frequency factor (A, and reaction order (n. The thermal degradation of dapsone and topiramate was followed a first-order kinetic behavior. The calculated data evidenced a zero-order kinetic for dimethylsulfone. The relative thermal stabilities of the studied drugs have been evaluated and follow the order DDS > TOP > MSM. The purity was determined using DSC for the studied compounds, in drug substances and products. The results were in agreement with the recommended pharmacopoeia and manufacturer methods. DSC curves obtained from the tablets suggest compatibility between the drugs, excipients and/or coformulated drugs. The fragmentation pathway of dapsone with mass spectrometry was taken as example, to correlate the thermal decomposition with the resulted MS-EI. The decomposition modes were investigated, and the possible fragmentation pathways were suggested by mass spectrometry.

  13. Toxicity of perfluorononanoic acid and perfluorooctane sulfonate to Daphnia magna

    Directory of Open Access Journals (Sweden)

    Guang-hua Lu

    2015-01-01

    Full Text Available In order to study toxicological effects of perfluorononanoic acid (PFNA, perfluorooctane sulfonate (PFOS, and their mixtures (PFNA/PFOS on Daphnia magna (D. magna, a suite of comprehensive toxicity tests were conducted, including a 48-h acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21-day life cycle. The biomarkers, including acetylcholinesterase (AChE, superoxide dismutase (SOD, and catalase (CAT activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including AChE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.

  14. Chronic perfluorooctane sulfonate (PFOS) exposure induces hepatic steatosis in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jiangfei; Lv, Suping; Nie, Shangfei; Liu, Jing; Tong, Shoufang; Kang, Ning; Xiao, Yanyan; Dong, Qiaoxiang [Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms (China); Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou, 325035 (China); Huang, Changjiang, E-mail: cjhuang5711@163.com [Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms (China); Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou, 325035 (China); Yang, Dongren, E-mail: yangdongren@yahoo.com [Zhejiang Provincial Key Laboratory for Technology and Application of Model Organisms (China); Institute of Environmental Safety and Human Health, Wenzhou Medical University, Wenzhou, 325035 (China)

    2016-07-15

    Highlights: • PFOS chronic exposure induces sex-dependent hepatic steotosis in zebrafish. • PFOS interferes with β-oxidation, lipid synthesis, and lipid hepatic export process. • Zebrafish could be used as an alternative model for PFOS chronic toxicity screening. - Abstract: Perfluorooctane sulfonate (PFOS), one persistent organic pollutant, has been widely detected in the environment, wildlife and human. Currently few studies have documented the effects of chronic PFOS exposure on lipid metabolism, especially in aquatic organisms. The underlying mechanisms of hepatotoxicity induced by chronic PFOS exposure are still largely unknown. The present study defined the effects of chronic exposure to low level of PFOS on lipid metabolism using zebrafish as a model system. Our findings revealed a severe hepatic steatosis in the liver of males treated with 0.5 μM PFOS as evidenced by hepatosomatic index, histological assessment and liver lipid profiles. Quantitative PCR assay further indicated that PFOS significantly increase the transcriptional expression of nuclear receptors (nr1h3, rara, rxrgb, nr1l2) and the genes associated with fatty acid oxidation (acox1, acadm, cpt1a). In addition, chronic PFOS exposure significantly decreased liver ATP content and serum level of VLDL/LDL lipoprotein in males. Taken together, these findings suggest that chronic PFOS exposure induces hepatic steatosis in zebrafish via disturbing lipid biosynthesis, fatty acid β-oxidation and excretion of VLDL/LDL lipoprotein, and also demonstrate the validity of using zebrafish as an alternative model for PFOS chronic toxicity screening.

  15. Chronic perfluorooctane sulfonate (PFOS) exposure induces hepatic steatosis in zebrafish

    International Nuclear Information System (INIS)

    Cheng, Jiangfei; Lv, Suping; Nie, Shangfei; Liu, Jing; Tong, Shoufang; Kang, Ning; Xiao, Yanyan; Dong, Qiaoxiang; Huang, Changjiang; Yang, Dongren

    2016-01-01

    Highlights: • PFOS chronic exposure induces sex-dependent hepatic steotosis in zebrafish. • PFOS interferes with β-oxidation, lipid synthesis, and lipid hepatic export process. • Zebrafish could be used as an alternative model for PFOS chronic toxicity screening. - Abstract: Perfluorooctane sulfonate (PFOS), one persistent organic pollutant, has been widely detected in the environment, wildlife and human. Currently few studies have documented the effects of chronic PFOS exposure on lipid metabolism, especially in aquatic organisms. The underlying mechanisms of hepatotoxicity induced by chronic PFOS exposure are still largely unknown. The present study defined the effects of chronic exposure to low level of PFOS on lipid metabolism using zebrafish as a model system. Our findings revealed a severe hepatic steatosis in the liver of males treated with 0.5 μM PFOS as evidenced by hepatosomatic index, histological assessment and liver lipid profiles. Quantitative PCR assay further indicated that PFOS significantly increase the transcriptional expression of nuclear receptors (nr1h3, rara, rxrgb, nr1l2) and the genes associated with fatty acid oxidation (acox1, acadm, cpt1a). In addition, chronic PFOS exposure significantly decreased liver ATP content and serum level of VLDL/LDL lipoprotein in males. Taken together, these findings suggest that chronic PFOS exposure induces hepatic steatosis in zebrafish via disturbing lipid biosynthesis, fatty acid β-oxidation and excretion of VLDL/LDL lipoprotein, and also demonstrate the validity of using zebrafish as an alternative model for PFOS chronic toxicity screening.

  16. Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) contamination from textiles.

    Science.gov (United States)

    Supreeyasunthorn, Phenpimuk; Boontanon, Suwanna K; Boontanon, Narin

    2016-01-01

    The goals of this study were to determine the concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in textiles and to determine PFOS and PFOA contamination in textile washing water. Quantification analysis was performed by high performance liquid chromatography coupled with tandem mass spectrometry. Analysis of 32 textile samples by methanol extraction revealed that the average concentrations of PFOS and PFOA were 0.18 µg m(-2) (0.02 to 0.61 µg m(-2)) and 2.74 µg m(-2) (0.31 to 14.14 µg m(-2)), respectively. Although the average concentration of PFOS found in textile samples was below European Union (EU) Commission regulations (textile samples had PFOA concentrations exceeding 1 µg m(-2). Thus, based on these results, the concentration of PFOA in products should also be regulated. Experiments on PFOS and PFOA leaching into washing water were conducted. The maximum concentrations of PFOS and PFOA were measured after the first washing; the concentrations gradually decreased with each subsequent washing. PFOS and PFOA migrated from textiles and were released into the environment, with disappearance percentages of 29.8% for PFOS and 99% for PFOA. The data presented in this study showed that textiles could be a significant direct and indirect source of PFOS and PFOA exposure for both humans and the environment.

  17. Preparation of 5-Bromo-2-naphthol: The Use of a Sulfonic Acid as a Protecting and Activating Group

    Directory of Open Access Journals (Sweden)

    Christopher Abelt

    2009-06-01

    Full Text Available The preparation of 5-bromo-2-naphthol (4 in three steps from 5-amino-2-naphthol (1 is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in 20% aq. sulfuric acid.

  18. Nitric Acid Dehydration Using Perfluoro Carboxylate and Mixed Sulfonate/Carboxylate Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Ames, Richard L. [Colorado School of Mines, Golden, CO (United States)

    2004-09-01

    Perfluoro ionomer membranes are tetrafluoro ethylene-based materials with microheterogeneous structures consisting of a hydrophobic polymer backbone and a hydrophilic side-chain cluster region. Due to the ionomer cluster morphology, these films exhibit unique transport properties. Recent investigations with perfluoro sulfonate and perfluoro sulfonate/carboxylate composite polymers have demonstrated their value in the dehydration of nitric acid and they show potential as an alternative to conventional, energy intensive unit operations in the concentration of acid feeds. As a result, investigations were conducted to determine the feasibility of using pure perfluoro carboxylate and mixed perfluoro sulfonate/carboxylate films for the dehydration of nitric acid because of the speculation of improved water selectivity of the carboxylate pendant chain. During the first phase of these investigations the effort was focused on generating a thin, solution cast perfluoro carboxylate ionomer film, to evaluate the general, chemical and physical characteristics of the polymer, and to assess the material's aqueous transport performance (flux and nitrate separation efficiencies) in pervaporation and high-pressure environments. Results demonstrated that generating robust solution-cast films was difficult yet a number of membranes survived high trans-membrane pressures up to 700 psig. General characterization of the solution cast product showed reduced ion exchange capacities when compared with thicker, ''as received'' perfluoro carboxylate and similar sulfonate films. Small angle x-ray scattering analysis results suggested that the solution cast carboxylate films contained a small fraction of sulfonate terminated side-chains. Aqueous transport experimentation showed that permeate fluxes for both pure water and nitric acid were approximately two orders of magnitude smaller for the carboxylate solution cast membranes when compared to their sulfonate

  19. Room-Temperature High-Efficiency Solid-State Triplet-Triplet Annihilation Up-Conversion in Amorphous Poly(olefin sulfone)s.

    Science.gov (United States)

    Turshatov, Andrey; Busko, Dmitry; Kiseleva, Natalia; Grage, Stephan L; Howard, Ian A; Richards, Bryce S

    2017-03-08

    Triplet-triplet annihilation up-conversion (TTA-UC) is a developing technology that can enable spectral conversion under sunlight. Previously, it was found that efficient TTA-UC can be realized in polymer hosts for temperatures above the polymer's glass transition (T > T g ). In contrast, TTA-UC with high quantum yield for temperatures below T g is rarely reported. In this article, we report new polymer hosts in which efficient TTA-UC is observed well below T g , when the polymer is in a fully solid state. The four poly(olefin sulfone) hosts were loaded with upconversion dyes, and absolute quantum yields of TTA-UC (η TTA-UC ) were measured. The highest value of η TTA-UC = 2.1% was measured for poly(1-dodecene sulfone). Importantly, this value was the same in vacuum and at ambient conditions, indicating that the host material acts as a good oxygen barrier. We performed time-resolved luminescence experiments in order to elucidate the impact of elementary steps of TTA-UC. In addition to optical characterization, we used magic angle spinning solid-state NMR experiments to estimate the T2 transverse relaxation time. Relatively long T2 times measured for poly(olefin sulfone)s indicate an enhanced nanoscale fluidity in the studied (co)polymers, which unexpectedly coexists with a rigidity on the macroscale. This would explain the exceptional triplet energy transfer between the guest molecules, despite the macroscopic rigidity.

  20. Synthesis and characterization of sulfonated polyesters derived from glycerol; Sintese e caracterizacao de poliesteres sulfonados obtidos a partir do glicerol

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, R.A.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Fiuza, R.P. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Quimica

    2010-07-01

    In this work were synthesized polyesters from glycerol and acid sulfonated phthalic previously. The materials were characterized by DSC, TGA, FTIR, SEM, XRD and XRF. The results showed effective sulfonation of phthalic acid. The presence of sulfonic groups promoted strong changes in the crystallinity of the new material makes the lens. The polyesters made from phthalic acid sulfonated combine characteristics such as heat resistance and groups that drivers potentiate the electrolyte for application in fuel cells proton exchange membrane and also for gas separation. (author)

  1. Anion exchange membranes based on terminally crosslinked methyl morpholinium-functionalized poly(arylene ether sulfone)s

    Science.gov (United States)

    Kwon, Sohyun; Rao, Anil H. N.; Kim, Tae-Hyun

    2018-01-01

    Azide-assisted terminal crosslinking of methyl morpholinium-functionalized poly(arylene ether sulfone) block copolymers yields products (xMM-PESs) suitable for use as anion exchange membranes. By combining the advantages of bulky morpholinium conductors and our unique polymer network crosslinked only at the termini of the polymer chains, we can produce AEMs that after the crosslinking show minimal loss in conductivity, yet with dramatically reduced water uptake. Terminal crosslinking also significantly increases the thermal, mechanical and chemical stability levels of the membranes. A high ion conductivity of 73.4 mS cm-1 and low water uptake of 26.1% at 80 °C are obtained for the crosslinked membrane with higher amount of hydrophilic composition, denoted as xMM-PES-1.5-1. In addition, the conductivity of the crosslinked xMM-PES-1.5-1 membrane exceeds that of its non-crosslinked counterpart (denoted as MM-PES-1.5-1) above 60 °C at 95% relative humidity because of its enhanced water retention capacity caused by the terminally-crosslinked structure.

  2. Synthesis and properties of a novel sulfonated poly(arylene ether ketone sulfone) membrane with a high β-value for direct methanol fuel cell applications

    International Nuclear Information System (INIS)

    Xu, Jingmei; Ma, Li; Han, Hailan; Ni, Hongzhe; Wang, Zhe; Zhang, Huixuan

    2014-01-01

    Highlights: • Introduction of carboxyl groups into copolymers resulted in extensive hydrogen bond. • The C-SPAEKS membranes had obviously hydrophilic/hydrophobic phase separation. • The membranes showed low methanol permeability and high β values. • The membranes exhibited good thermal property and desirable mechanical performance. - Abstract: Sulfonated poly(arylene ether ketone sulfone) membranes containing carboxylic acid groups (C-SPAEKS) with different degrees of sulfonation were synthesized by the nucleophilic aromatic substitution reactions of 4-carboxylphenyl hydroquinone (4C-PH), bisphenol A, 3,3′-disulfonated 4,4′-dichlorodiphenyl sulfone, and 4,4′-difluorobenzophenone. The Fourier transform infrared and 1 H NMR analyses of C-SPAEKS revealed the presence of carboxylic acid groups in the C-SPAEKS membranes. The membranes exhibited a low swelling degree and methanol crossover level. The effects of different degrees of sulfonation on the water uptake, proton conductivity, and methanol permeability coefficient of the membranes were studied. The maximum proton conductivity of C-SPAEKS-80 membrane at room temperature was 0.069 S cm −1 , which was higher than that of Nafion ® 117 membrane. The methanol permeability coefficient of C-SPAEKS-80 membrane was 9.15 × 10 −7 cm 2 s −1 at 20 °C, much lower than that of Nafion 117 membrane (22.9 × 10 −7 cm 2 s −1 ). Furthermore, the carboxyl group-containing membranes exhibited a high β-value, further confirming that this series of membranes possess excellent comprehensive performance and can be applied in direct methanol fuel cells

  3. Las creencias y las concepciones. Perspectivas complementarias

    Directory of Open Access Journals (Sweden)

    Fuensanta HERNÁNDEZ PINA

    2011-01-01

    Full Text Available Las creencias y las concepciones sobre la enseñanza y el aprendizaje que los profesores sostienen como docentes es una línea de investigación que está suponiendo un avance en el conocimiento sobre factores relevantes para la mejor de la educación. Desde hace más de dos décadas han sido numerosos los investigadores que han venido proporcionando resultados de investigación en torno a las creencias y las concepciones de la enseñanza y el aprendizaje lo que ha supuesto establecer nuevas e interesantes interpretaciones en dicha relación. En el trabajo que presentamos se abordan algunas de las aportaciones sobre dichas creencias y sobre las concepciones de la enseñanza y el aprendizaje.

  4. Neurotoxicity of perfluorooctane sulfonate to hippocampal cells in adult mice.

    Directory of Open Access Journals (Sweden)

    Yan Long

    Full Text Available Perfluorooctane sulfonate (PFOS is a ubiquitous pollutant and found in the environment and in biota. The neurotoxicity of PFOS has received much concern among its various toxic effects when given during developing period of brain. However, little is known about the neurotoxic effects and potential mechanisms of PFOS in the mature brain. Our study demonstrated the neurotoxicity and the potential mechanisms of PFOS in the hippocampus of adult mice for the first time. The impairments of spatial learning and memory were observed by water maze studies after exposure to PFOS for three months. Significant apoptosis was found in hippocampal cells after PFOS exposure, accompanied with a increase of glutamate in the hippocampus and decreases of dopamine (DA and 3,4-dihydrophenylacetic acid (DOPAC in Caudate Putamen in the 10.75 mg/kg PFOS group. By two-dimensional fluorescence difference in gel electrophoresis (2D-DIGE analysis, seven related proteins in the hippocampus that responded to PFOS exposure were identified, among which, Mib1 protein (an E3 ubiquitin-protein ligase, Herc5 (hect domain and RLD 5 isoform 2 and Tyro3 (TYRO3 protein tyrosine kinase 3 were found down-regulated, while Sdha (Succinate dehydrogenase flavoprotein subunit, Gzma (Isoform HF1 of Granzyme A precursor, Plau (Urokinase-type plasminogen activator precursor and Lig4 (DNA ligase 4 were found up-regulated in the 10.75 mg/kg PFOS-treated group compare with control group. Furthermore, we also found that (i increased expression of caspase-3 protein and decreased expression of Bcl-2, Bcl-XL and survivin proteins, (ii the increased glutamate release in the hippocampus. All these might contribute to the dysfunction of hippocampus which finally account for the impairments of spatial learning and memory in adult mice.

  5. Grafting titanium nitride surfaces with sodium styrene sulfonate thin films

    Science.gov (United States)

    Zorn, Gilad; Migonney, Véronique; Castner, David G.

    2014-01-01

    The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ∼1.5 and ∼1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260 ± 70 ng/cm2. PMID:25280842

  6. Tanshinone IIA sodium sulfonate facilitates endocytic HMGB1 uptake.

    Science.gov (United States)

    Zhang, Yusong; Li, Wei; Zhu, Shu; Jundoria, Arvin; Li, Jianhua; Yang, Huan; Fan, Saijun; Wang, Ping; Tracey, Kevin J; Sama, Andrew E; Wang, Haichao

    2012-12-01

    Our seminal discovery of high mobility group box 1 (HMGB1) as a late mediator of lethal systemic inflammation has prompted a new field of investigation for the development of experimental therapeutics. We previously reported that a major Danshen ingredient, tanshinone IIA sodium sulfonate (TSN-SS), selectively inhibited endotoxin-induced HMGB1 release and conferred protection against lethal endotoxemia and sepsis. To investigate the underlying mechanisms by which TSN-SS effectively inhibits HMGB1 release, we examined whether TSN-SS stimulates HMGB1 uptake by macrophages and whether genetic depletion of HMGB1 receptors [e.g., toll-like receptors (TLR)2, TLR4, or the receptor for advanced glycation end product (RAGE)] or pharmacological inhibition of endocytosis impairs TSN-SS-facilitated HMGB1 cellular uptake. TSN-SS stimulated internalization of exogenous HMGB1 protein into macrophage cytoplasmic vesicles that subsequently co-localized with microtubule-associated protein light chain 3 (LC3)-positive punctate structures (likely amphisomes). Meanwhile, it time-dependently elevated cellular levels of internalized HMGB1, leading to elevated LC3-II production and aggregation. Although genetic depletion of TLR2, TLR4, and/or RAGE did not impair TSN-SS-mediated HMGB1 uptake, specific inhibitors of the clathrin- and caveolin-dependent endocytosis significantly impaired TSN-SS-mediated HMGB1 uptake. Co-treatment with a lysosomal inhibitor, bafilomycin A1, led to enhanced accumulation of endogenous LC3-II and internalized exogenous HMGB1 in TSN-SS/rHMGB1-treated macrophages. Taken together, these findings suggest that TSN-SS may facilitate HMGB1 endocytic uptake, and subsequently delivered it to LC3-positive vacuoles (possibly amphisomes) for degradation via a lysosome-dependent pathway. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Direct Olefination of Alcohols with Sulfones by Using Heterogeneous Platinum Catalysts.

    Science.gov (United States)

    Siddiki, S M A Hakim; Touchy, Abeda Sultana; Kon, Kenichi; Shimizu, Ken-Ichi

    2016-04-18

    Carbon-supported Pt nanoparticles (Pt/C) were found to be effective heterogeneous catalysts for the direct Julia olefination of alcohols in the presence of sulfones and KOtBu under oxidant-free conditions. Primary alcohols, including aryl, aliphatic, allyl, and heterocyclic alcohols, underwent olefination with dimethyl sulfone and aryl alkyl sulfones to give terminal and internal olefins, respectively. Secondary alcohols underwent methylenation with dimethyl sulfone. Under 2.5 bar H2, the same reaction system was effective for the transformation of alcohol OH groups to alkyl groups. Structural and mechanistic studies of the terminal olefination system suggested that Pt(0) sites on the Pt metal particles are responsible for the rate-limiting dehydrogenation of alcohols and that KOtBu may deprotonate the sulfone reagent. The Pt/C catalyst was reusable after the olefination, and this method showed a higher turnover number (TON) and a wider substrate scope than previously reported methods, which demonstrates the high catalytic efficiency of the present method. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Highly Sulfonated Diamine Synthesized Polyimides and Protic Ionic Liquid Composite Membranes Improve PEM Conductivity

    Directory of Open Access Journals (Sweden)

    Bor-Kuan Chen

    2015-06-01

    Full Text Available A novel sulfonated diamine was synthesized from 1,4-bis(4-aminophenoxy benzene [pBAB]. Sulfonated polyimides (SPIs were synthesized from sulfonated pBAB, 1,4-bis(4-aminophenoxy-2-sulfonic acid benzenesulfonic acid [pBABTS], various diamines and aromatic dianhydrides. Composite proton exchange membranes (PEMs made of novel SPIs and a protic ionic liquid (PIL 1-vinyl-3-H-imidazolium trifluoromethanesulfonate [VIm][OTf] showed substantially increased conductivity. We prepared an SPI/PIL composite PEM using pBABTS, 4,4′-(9-fluorenylidene dianiline (9FDA as diamine, 3,3′,4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA as dianhydride and 40 wt % [VIm][OTf] with a high conductivity of 16 mS/cm at 120 °C and anhydrous condition. pBABTS offered better conductivity, since the chemical structure had more sulfonated groups that provide increased conductivity. The new composite membrane could be a promising anhydrous or low-humidity PEM for intermediate or high-temperature fuel cells.

  9. Copoly(arlene ether)s containing pendant sulfonic acid groups as proton exchange membrane

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung [Los Alamos National Laboratory; Kim, Dae Sik [CANADA NRC; Robertson, Gilles [CANADA NRC; Guiver, Michael [CANADA NRC

    2008-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The P AE and PAEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2-phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. The sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sP AE and sP AEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (DS) of 1.0 had high ion exchange capacities (IEC{sub v}(wet) (volume-based, wet state)) of 1.77 and 2.55 meq./cm{sup 3}, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5-51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the area of outstanding properties in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based). Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  10. The host cell sulfonation pathway contributes to retroviral infection at a step coincident with provirus establishment.

    Science.gov (United States)

    Bruce, James W; Ahlquist, Paul; Young, John A T

    2008-11-01

    The early steps of retrovirus replication leading up to provirus establishment are highly dependent on cellular processes and represent a time when the virus is particularly vulnerable to antivirals and host defense mechanisms. However, the roles played by cellular factors are only partially understood. To identify cellular processes that participate in these critical steps, we employed a high volume screening of insertionally mutagenized somatic cells using a murine leukemia virus (MLV) vector. This approach identified a role for 3'-phosphoadenosine 5'-phosphosulfate synthase 1 (PAPSS1), one of two enzymes that synthesize PAPS, the high energy sulfate donor used in all sulfonation reactions catalyzed by cellular sulfotransferases. The role of the cellular sulfonation pathway was confirmed using chemical inhibitors of PAPS synthases and cellular sulfotransferases. The requirement for sulfonation was mapped to a stage during or shortly after MLV provirus establishment and influenced subsequent gene expression from the viral long terminal repeat (LTR) promoter. Infection of cells by an HIV vector was also shown to be highly dependent on the cellular sulfonation pathway. These studies have uncovered a heretofore unknown regulatory step of retroviral replication, have defined a new biological function for sulfonation in nuclear gene expression, and provide a potentially valuable new target for HIV/AIDS therapy.

  11. [Dependence of the anticoagulant activity of starch and inulin on their degree of sulfonation].

    Science.gov (United States)

    Drozd, N N; Torlopov, M A; Kuzhim, A A; Makarov, V A

    2012-01-01

    We have studied a relationship between the degree of sulfonation and anticoagulant activity of starch from Solanum tuberosum (molecular weight, 25000-30000 Da; sulfonation degree, 0.4-2.5) and inulin from Helianthus tuberosus (molecular weight, 7000-8000 Da; sulfonation degree, 0.6-1.6). Starch and inulin sulfates (i) increased the time of appearance of fibrin clots in plasma in coagulometric tests and (ii) reduced (via antithrombin) the rate of thrombin-induced hydrolysis of a chromogen substrate. The antithrombin (aIIa) activity of starch sulfates reached 16.8-70.0 IU/mg and the activity against factor Xa (aXa activity) was 2.3-16.6 IU/mg. The antithrombin activity of inulin sulfates was within 5.5-11.4 IU/mg and the activity against factor Xa (aXa activity) was within 0-1.4 IU/mg. An increase in the degree of sulfonation led to a growth in the anticoagulant activity of starch sulfates. The anticoagulant activity of starch sulfates and inulin sulfate with sulfonation degree 1.0 is mediated by antithrombin, which is the plasma inhibitor of serine proteases.

  12. Potential contact and intraocular lenses based on hydrophilic/hydrophobic sulfonated syndiotactic polystyrene membranes

    Directory of Open Access Journals (Sweden)

    Simona Zuppolini

    2017-10-01

    Full Text Available Crystalline films of syndiotactic polystyrene (s-PS, a commercially available thermoplastic polymer, having a highly hydrophilic amorphous phase, were achieved by using a mild solid-state sulfonation procedure. Despite the used mild process conditions, an easy and uniform sulfonation of the phenyl rings of the amorphous phase is obtained. The crystallinity of the polymer was not affect by the sulfonation degree (S, at least at S less than 20%, and the obtained polymer films show the nanoporous crystalline form of s-PS. As widely reported in literature, the nanoporous nature of the polymer crystalline phase gives to these materials the ability to absorb and release organic molecules of appropriate size and polarity. This property, coupled to transparency, makes these materials potentially useful intraocular lens (IOLs and contact lens applications. Sulfonation procedure and sulfonated film samples characterization by using wide-angle X-ray diffraction (WAXD, Fourier-transform infrared (FTIR and ultraviolet-visible (UV-vis spectroscopy techniques and water sorption tests were reported. Furthermore, the biocompatibility study demonstrated no cytotoxicity and appropriate cell interaction properties for the specific applications.

  13. The host cell sulfonation pathway contributes to retroviral infection at a step coincident with provirus establishment.

    Directory of Open Access Journals (Sweden)

    James W Bruce

    2008-11-01

    Full Text Available The early steps of retrovirus replication leading up to provirus establishment are highly dependent on cellular processes and represent a time when the virus is particularly vulnerable to antivirals and host defense mechanisms. However, the roles played by cellular factors are only partially understood. To identify cellular processes that participate in these critical steps, we employed a high volume screening of insertionally mutagenized somatic cells using a murine leukemia virus (MLV vector. This approach identified a role for 3'-phosphoadenosine 5'-phosphosulfate synthase 1 (PAPSS1, one of two enzymes that synthesize PAPS, the high energy sulfate donor used in all sulfonation reactions catalyzed by cellular sulfotransferases. The role of the cellular sulfonation pathway was confirmed using chemical inhibitors of PAPS synthases and cellular sulfotransferases. The requirement for sulfonation was mapped to a stage during or shortly after MLV provirus establishment and influenced subsequent gene expression from the viral long terminal repeat (LTR promoter. Infection of cells by an HIV vector was also shown to be highly dependent on the cellular sulfonation pathway. These studies have uncovered a heretofore unknown regulatory step of retroviral replication, have defined a new biological function for sulfonation in nuclear gene expression, and provide a potentially valuable new target for HIV/AIDS therapy.

  14. Reactions of aromatic nitro compounds. LVI. Reaction of polynitrodiphenyl sulfones with acetone and potassium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Alekhina, N.N.; Gitis, S.S.; Grudtsyn, Yu.D.; Kaminskii, A.Ya.

    1986-11-20

    The Yanovskii sigma complexes of 2,4-dinitrophenyl sulfone and 2,4-dinitro-, 2,4,4'-trinitro-, and 2,2',4,4'-tetranitrodiphenylsulfones were obtained and isolated in the crystalline form. It was established by PMR, IR, and electronic spectroscopy that they are all products from addition of the acetone residue to the fifth carbon atom of the dinitro-substituted ring; in contrast to polynitrodiphenyl sulfides, the isomeric adducts at the C/sup 3/ atom are not formed. Compared with the analogous complexes of sulfides, the synthesized products possess enhanced thermodynamic stability in an acetone-methanol medium. In DMSO they are rapidly decomposed by traces of water to dinitrophenolate and the corresponding arenesulfinic acids. The decomposition of the methyl dinitrophenyl sulfone complex takes place with preferential substitution of the para-nitro group and the formation of methyl 2-nitro-4-hydroxyphenyl sulfone.

  15. Sulfonation degree effect on ion-conducting SPEEK-titanium oxide membranes properties

    Directory of Open Access Journals (Sweden)

    Jacqueline Costa Marrero

    2017-09-01

    Full Text Available Abstract Polymeric membranes were developed using a SPEEK (sulfonated poly(ether ether ketone polymer matrix, containing titanium oxide (TiO2 (incorporated by sol-gel method. SPEEK with different sulfonation degrees (SD: 63% and 50% were used. The influence of sulfonation degree on membrane properties was investigated. The thermal analysis (TGA and DTGA and X-ray diffraction (XRD were carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS was carried out to evaluate the proton conductivity of the membranes. The proton conductivities in water were of 3.25 to 37.08 mS.cm-1. Experimental data of impedance spectroscopy were analyzed with equivalent circuits using the Zview software, and the results showed that, the best fitted was at 80 °C.

  16. Comparative Study of Sulfonated and Phosphorylated Commercial Polytetrafluoroethylene (PTFE) Grafted with Styrene for Fuel Cell Application

    International Nuclear Information System (INIS)

    Abdel-Hady, E.E.; Abdel-Hamed, M.O.; El-Sharkawy, M.R.M.; ELtoony, M.M.

    2010-01-01

    The aim of this project is to develop novel, low cost high temperature membranes specifically for automotive fuel cell use. Styrene grafted commercial PTFE which carried out by simultaneous - irradiation was taken. Sulfonation was performed using chloro sulfonic acid for different times, while phosphorylation was done by two techniques. Synergistic effect was studied by carrying out sulfonation for phosphorylated styrene grafted PTFE. Mechanical investigation was performed by measuring tensile strength and thermal characterization was discussed by DSC measurements. Scanning Electron Microscopy (SEM) and Positron Annihilation Lifetime Spectroscopy (PALS) measurements were preformed to characterize the free volume properties by using fast-fast coincidence technique. While the crystallinity and the crystalline size were studied by X-ray diffraction (XRD). Water uptake and ion exchange capacity were determined prior to measure the electrical conductivity and capacitance at different frequencies to assure the availability of the membrane for using in fuel cell application.

  17. Sulfonation degree effect on ion-conducting SPEEK-titanium oxide membranes properties

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Jacqueline Costa; Gomes, Ailton de Souza; Dutra Filho, José Carlos, E-mail: jacquecosta@gmail.com [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Instituto de Macromoléculas Professora Eloisa Mano; Hui, Wang Shu [Universidade de São Paulo (USP), São Paulo, SP (Brazil). Departamento de Engenharia Metalúrgica e de Materiais; Oliveira, Vivianna Silva de [Escola Técnica Rezende Rammel (ETRR), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Polymeric membranes were developed using a SPEEK (sulfonated poly(ether ether ketone)) polymer matrix, containing titanium oxide (TiO{sub 2}) (incorporated by sol-gel method). SPEEK with different sulfonation degrees (SD): 63% and 50% were used. The influence of sulfonation degree on membrane properties was investigated. The thermal analysis (TGA and DTGA) and X-ray diffraction (XRD) were carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluate the proton conductivity of the membranes. The proton conductivities in water were of 3.25 to 37.08 mS.cm{sup -1}. Experimental data of impedance spectroscopy were analyzed with equivalent circuits using the Zview software, and the results showed that, the best fitted was at 80 °C. (author)

  18. Synthesis of fully and partially sulfonated polyanilines derived from ortanilic acid: An electrochemical and electromicrogravimetric study

    International Nuclear Information System (INIS)

    Cano Marquez, Abraham Guadalupe; Torres Rodriguez, Luz Maria; Montes Rojas, Antonio

    2007-01-01

    The electrochemical polymerization of 2-aminobenzene sulfonic acid, also called ortanilic acid (o-ASA), on a gold electrode precoated with polyaniline (PANI), has been carried out. We proved that the electropolymerization of o-ASA is enhanced on PANI electrodes, resulting in thicker films obtained in aqueous media at room temperature. The electrosynthesized film (P(o-ASA)) was characterized by cyclic voltammetry, FTIR and nuclear magnetic resonance. The compensation of P(o-ASA) charge was evaluated using electrochemical quartz crystal microbalance combined with cyclic voltammetry, which showed that the electroneutralization process mainly involves cations. Additionally, copolymers of aniline and o-ASA were electrosynthesized, using a metallic electrode modified with PANI also as a working electrode. The degree of sulfanation of copolymers has been modulated with the proportions of monomers in the electrosynthesis solution. The studies reveal a more important participation of cations in fully sulfonated polyaniline than in partially sulfonated polyaniline

  19. Synthesis and Process Optimization of Electrospun PEEK-Sulfonated Nanofibers by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Carlo Boaretti

    2015-07-01

    Full Text Available In this study electrospun nanofibers of partially sulfonated polyether ether ketone have been produced as a preliminary step for a possible development of composite proton exchange membranes for fuel cells. Response surface methodology has been employed for the modelling and optimization of the electrospinning process, using a Box-Behnken design. The investigation, based on a second order polynomial model, has been focused on the analysis of the effect of both process (voltage, tip-to-collector distance, flow rate and material (sulfonation degree variables on the mean fiber diameter. The final model has been verified by a series of statistical tests on the residuals and validated by a comparison procedure of samples at different sulfonation degrees, realized according to optimized conditions, for the production of homogeneous thin nanofibers.

  20. Synthesis and Process Optimization of Electrospun PEEK-Sulfonated Nanofibers by Response Surface Methodology

    Science.gov (United States)

    Boaretti, Carlo; Roso, Martina; Lorenzetti, Alessandra; Modesti, Michele

    2015-01-01

    In this study electrospun nanofibers of partially sulfonated polyether ether ketone have been produced as a preliminary step for a possible development of composite proton exchange membranes for fuel cells. Response surface methodology has been employed for the modelling and optimization of the electrospinning process, using a Box-Behnken design. The investigation, based on a second order polynomial model, has been focused on the analysis of the effect of both process (voltage, tip-to-collector distance, flow rate) and material (sulfonation degree) variables on the mean fiber diameter. The final model has been verified by a series of statistical tests on the residuals and validated by a comparison procedure of samples at different sulfonation degrees, realized according to optimized conditions, for the production of homogeneous thin nanofibers. PMID:28793427

  1. An electrochemical study in aqueous solutions on the binding of dopamine to a sulfonated cyclodextrin host

    International Nuclear Information System (INIS)

    Hendy, Gillian M.; Breslin, Carmel B.

    2012-01-01

    Highlights: ► DA and Sβ-CD form an Inclusion complex. ► Electrochemical techniques demonstrated this inclusion complex. ► The association constant, K, was computed as 331.3. ► 1:1 stoichiometry for the inclusion complex was deduced from a Job's plot analysis. ► NMR studies confirmed the structural information on the inclusion complex. - Abstract: Clear evidence for the formation of a weak inclusion complex between dopamine (DA) and a sulfonated β-CD host in aqueous solution was obtained using a combination of electrochemical approaches. Using cyclic voltammetry, a distinct increase in the oxidation potential of DA and a reduction in the peak oxidation current were observed on adding an excess concentration of the sulfonated β-CD to the electrolyte solution. Equally, a clear increase in the half-wave oxidation potential of DA was observed in the presence of the sulfonated β-CD using rotating disc voltammetry. The association constant, K, was computed as 331.3 ± 5.8, indicating the formation of a weak inclusion complex, while a 1:1 stoichiometry for the inclusion complex was deduced from a Job's plot analysis. The rate constant for the oxidation of DA was found to decrease on formation of the inclusion complex. This was attributed to higher reorganization energy for the oxidation of the included DA. These changes in the electrochemistry of DA were not observed when an excess of the smaller sulfonated α-CD was added to the electrolyte, indicating that these variations are not connected with simple electrostatic interactions between the protonated DA and the anionic sulfonated groups. It is proposed that the aromatic ring of the DA molecule includes within the cyclodextrin cavity, while the protonated amine group remains outside the cavity, bound electrostatically with the anionic sulfonated groups.

  2. Particle size effects of sulfonated graphene supported Pt nanoparticles on ethanol electrooxidation

    International Nuclear Information System (INIS)

    Sun, Chia-Liang; Tang, Jui-Shiang; Brazeau, Nicolas; Wu, Jhing-Jhou; Ntais, Spyridon; Yin, Chung-Wei; Chou, Hung-Lung; Baranova, Elena A.

    2015-01-01

    Highlights: • Pt colloidal nanoparticles with five mean diameters are synthesized. • Size-selected Pt nanoparticles are loaded on sulfonated graphene (sG). • Sulfonic acid functional groups atop graphene donate charge to Pt. • Pt-sG catalysts are used for ethanol oxidation reaction (EOR). • Pt-sG(2.5 nm) has the highest peak current density in EOR. - Abstract: Fuel cells are promising alternative in automobile and stationary power generation. Direct ethanol fuel cells (DEFCs) offer significant advantages due to the non-toxicity and renewability of ethanol as well as its high power density. Development of the efficient catalysts for ethanol oxidation reaction (EOR) has attracted great attention and represents one of the major challenges in electrocatalysis. Graphene, one-atom thick nanocarbon materials, has attracted much attention recently in a variety of applications. The sulfonation of graphene is able to make it hydrophilic, which enhances its dispersibility in aqueous solvents. Furthermore, sulfonation increases the adsorption and uniform distribution of the Pt nanoparticles, which increases both the electrocatalytic activity and the durability. In this study, theoretical calculations demonstrated that the sulfonate functional group can donate charge to Pt, enhanced the adsorption energy of Pt, and then reduce the adsorption energy of CO on Pt. Then experimentally five kinds of Pt/sulfonated-graphene (Pt/sG) catalysts were synthesized via the control of pH values during the preparation of five-selected colloidal nanoparticles. Among all catalysts, Pt-sG(2.5 nm) has the highest peak current density in EOR

  3. Synthesis and detection of toltrazuril sulfone and its pharmacokinetics in horses following administration in dimethylsulfoxide.

    Science.gov (United States)

    Dirikolu, L; Karpiesiuk, W; Lehner, A F; Hughes, C; Granstrom, D E; Tobin, T

    2009-08-01

    Triazine-based antiprotozoal agents are known for their lipophylic characteristics and may therefore be expected to be well absorbed following oral administration. However, although an increase in lipid solubility generally increases the absorption of chemicals, extremely lipid-soluble chemicals may dissolve poorly in gastrointestinal (GI) fluids, and their corresponding absorption and bioavailability would be low. Also, if the compound is administered in solid form and is relatively insoluble in GI fluids, it is likely to have limited contact with the GI mucosa, and therefore, its rate of absorption will be low. Based on the above considerations, we sought a solvent with low or no toxicity that would maintain triazine agents in solution. As the oral route is most preferred for daily drug therapy, such a solvent would allow an increased rate of absorption following oral administration. In present study, it was demonstrated that dimethylsulfoxide (DMSO) increased the oral bioavailability of toltrazuril sulfone (Ponazuril) threefold, relative to oral administrations of toltrazuril sulfone suspended in water. The cross-over study of toltrazuril sulfone formulated in DMSO indicated that the absolute oral bioavailability of toltrazuril sulfone in DMSO is 71%. The high bioavailability of the DMSO-preparation suggests that its daily oral administration will routinely yield effective plasma and cerebral spinal fluid (CSF) concentrations in all horses treated. Also, this improved formulation would allow clinicians to administer loading doses of toltrazuril sulfone in acute cases of Equine Protozoal Myeloencephalitis. Another option would involve administration of toltrazuril sulfone in DMSO mixed with feed (1.23 kg daily dose) meeting the US Food and Drug Administration (FDA) recommendations for the levels of DMSO permissible in pharmaceutical preparations.

  4. Formation of core (polystyrene)-shell (polybenzimidazole) nanoparticles using sulfonated polystyrene as template.

    Science.gov (United States)

    Hazarika, Mousumi; Arunbabu, Dhamodaran; Jana, Tushar

    2010-11-15

    We report formation of core (polystyrene)-shell (polybenzimidazole) nanoparticles from a new blend system consisting of an amorphous polymer polybenzimidazole (PBI) and an ionomer sodium salt of sulfonated polystyrene (SPS-Na). The ionomer used for the blending is spherical in shape with sulfonate groups on the surface of the particles. An in depth investigation of the blends at various sulfonation degrees and compositions using Fourier transform infrared (FT-IR) spectroscopy provides direct evidence of specific hydrogen bonding interactions between the N-H groups of PBI and the sulfonate groups of SPS-Na. The disruption of PBI chains self association owing to the interaction between the functional groups of these polymer pairs is the driving force for the blending. Thermodynamical studies carried out by using differential scanning calorimeter (DSC) establish partially miscible phase separated blending of these polymers in a wider composition range. The two distinguishable glass transition temperatures (T(g)) which are different from the neat components and unaltered with the blends composition attribute that the domain size of heterogeneity (d(d)) of the blends is >20 nm since one of the blend component (SPS-Na particle) diameter is ∼70 nm. The diminish of PBI chains self association upon blending with SPS-Na particles and the presence of invariant T(g)'s of the blends suggest the wrapping of PBI chains over the SPS-Na spherical particle surface and hence resulting a core-shell morphology. Transmission electron microscopy (TEM) study provides direct evidence of core-shell nanoparticle formation; where core is the polystyrene and shell is the PBI. The sulfonation degree affects the blends phase separations. The higher degree of sulfonation favors the disruption of PBI self association and thus forms partially miscible two phases blends with core-shell morphology. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Synthesis and ATRP of novel fluorinated aromatic monomer with pendant sulfonate group

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2013-01-01

    Novel, fluorinated monomer with pendant sulfonate group was synthesized utilizing a two-step derivatization of 2,3,4,5,6-pentafluorostyrene (FS). The first step was a nucleophilic substitution of the fluorine atom in para position by hydroxyl group followed by sulfopropylation. The monomer...... was polymerized under aqueous ATRP conditions to yield phenyl-fluorinated aromatic homopolymer bearing pendant sulfonates on each repeating unit. Furthermore, this polymer was used as macroinitiator for the ATRP of poly(ethylene glycol) methacrylate. The polymers were characterized by 1H NMR, SEC and FTIR...

  6. Construction of Functionalized Annulated Sulfone via SO2/I Exchange of Cyclic Diaryliodonium Salts.

    Science.gov (United States)

    Wang, Ming; Chen, Shihao; Jiang, Xuefeng

    2017-09-15

    A straightforward protocol for diarylannulated sulfone construction is efficiently established via SO 2 /I exchange of iodonium(III) salts. Readily available inorganic Na 2 S 2 O 5 was served as a safe and convenient SO 2 surrogate. Diverse functionalized diarylannulated sulfones were smoothly achieved in good to excellent yields with great functional group compatibility. Organic light emitting diodes (OLEDs) material molecules were subsequently established via this method in gram scale. The unsymmetrical conjugated systems with donor-acceptor groups and π-conjugation bridges motifs, which substantially communicate electron mobility in semiconductor material molecules, were successfully afforded under the facile conditions of the exchange strategy.

  7. The radiation chemistry of aqueous solutions of sodium 9,10-anthraquinone-2-sulfonate

    International Nuclear Information System (INIS)

    Burchill, C.E.; Smith, D.M.; Charlton, J.L.

    1976-01-01

    The 60 Co γ-radiolysis of aqueous solutions of sodium 9,10-anthraquinone-2-sulfonate has been studied in acidic, unbuffered, and alkaline conditions and with addition of N 2 O and 2-propanol. Mechanisms are proposed to account for the yields of H 2 O 2 and hydroxylated anthraquinone sulfonates. In neutral solution, in the absence of O 2 , the OH and e - adducts undergo preferential cross termination. Reduction of the OH adduct leads to dehydration and regeneration of the quinone. (author)

  8. Microwave Assisted Hydrolysis of Holocellulose Catalyzed with Sulfonated Char Derived from Lignin-Rich Residue

    Directory of Open Access Journals (Sweden)

    Kui Wang

    2015-01-01

    Full Text Available A microwave assisted green process has been developed for production of sugars through liquefying holocellulose catalyzed with sulfonated char derived from the lignin-rich residue produced during pretreatment of lignocellulose. Various reaction parameters including the hydrolysis temperature, hydrolysis time, catalyst content, and the ratio of water to feedstock were evaluated. The maximum sugars yield of 82.6% (based on the dry mass of holocellulose was obtained under the optimum reaction conditions. The sulfonated char showed superior catalytic performance to that of dilute sulfuric acid in converting holocellulose into sugars under microwave irradiation.

  9. Removal of dyes from water using crosslinked aminomethane sulfonic acid based resin.

    Science.gov (United States)

    Kaner, Damla; Saraç, Ayfer; Senkal, Bahire Filiz

    2010-08-01

    A new polymeric resin with amino sulfonic acid pendant functions has been prepared for the extraction of acidic and basic dyes from water. Beaded polymer supports were prepared by suspension polymerization of vinyl benzyl chloride (0.9 mol) and ethylene glycol dimethacrylate (0.1 mol). The resulting copolymer beads were modified with amino methane sulfonic acid. The dye adsorption capacity of the resin was found as 0.16 g dye/g resin for ramazol black and 0.15 g dye/g resin for crystal violet. The pH depending measurements and dye sorption kinetics of the resin were also investigated.

  10. A Facile and Mild Synthesis of Trisubstituted Allylic Sulfones from Morita-Baylis-Hillman Carbonates

    Directory of Open Access Journals (Sweden)

    Lin Jiang

    2015-05-01

    Full Text Available An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%–99% with good to high selectivity (Z/E from 79:21 to >99:1. Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.

  11. A facile and mild synthesis of trisubstituted allylic sulfones from Morita-Baylis-Hillman carbonates.

    Science.gov (United States)

    Jiang, Lin; Li, Yong-Gen; Zhou, Jiang-Feng; Chuan, Yong-Ming; Li, Hong-Li; Yuan, Ming-Long

    2015-05-07

    An efficient and catalyst-free synthesis of trisubstituted allylic sulfones through an allylic sulfonylation reaction of Morita-Baylis-Hillman (MBH) carbonates with sodium sulfinates has been developed. Under the optimized reaction conditions, a series of trisubstituted allylic sulfones were rapidly prepared in good to excellent yields (71%-99%) with good to high selectivity (Z/E from 79:21 to >99:1). Compared with known synthetic methods, the current protocol features mild reaction temperature, high efficiency and easily available reagents.

  12. Allylic C-S Bond Construction through Metal-Free Direct Nitroalkene Sulfonation.

    Science.gov (United States)

    Lei, Xue; Zheng, Lei; Zhang, Chuanxin; Shi, Xiaodong; Chen, Yunfeng

    2018-02-16

    A metal-free, open-flask protocol was developed for the preparation of allylic sulfones through direct condensation of sodium arylsulfinates and β,β-disubstituted nitroalkenes. The key step of this process was the Lewis base-promoted equilibrium between nitroalkenes and allylic nitro compounds. Through this process, the readily available conjugated nitroalkenes can be easily converted into allylic nitro compounds, which contain more reactive C═C bonds toward the sulfonyl radical addition. As a result, allylic sulfones were prepared in excellent yields with a broad substrate scope under mild conditions.

  13. Spectroscopic investigation of sulfonate phthalocyanine to probe enzyme reactions for heavy metals detection

    International Nuclear Information System (INIS)

    Chaure, Shweta; Paul, Deepen; Vadagma, Pankaj; Ray, Asim K.

    2010-01-01

    Optical absorption and Raman spectra of the sulfonated copper phthalocyanine (CuTsPc) layer were exploited for detection of cadmium (Cd) contaminants in water. Acetylcholine esterase was immobilized by freely suspending them in calcium alginate microbeads and this gel was then spincoated on the drop cast sulfonated copper phthalocyanine film on a glass substrate to form a bilayer. The inhibition of catalytic reaction between acetylcholine chloride and enzyme due to Cd contaminants was monitored by recording changes in spectra of drop cast CuTsPc as an indicator. The detection limit of cadmium content in water was found to be 1 ppm.

  14. Sulfonic-based precursors (SAPs for silica mesostructures: Advances in synthesis and applications

    Directory of Open Access Journals (Sweden)

    Sadegh Rostamnia*

    2016-01-01

    Full Text Available Sulfonic acid-based precursors (SAP play an important role in tailoring mesoporous silica’s and convert them to a solid acid catalyst with a Bronsted-type nature. These kinds of solid acids contribute to sustainable and green chemistry by their heterogeneous, recyclable, and high efficiency features. Therefore, knowing the properties and reactivity of SAPs can guide us to manufacture a sulfonated mesostructures compatible with reaction type and conditions. In the present review, some of the important SAPs, their reactivity and mechanism of functionalization are discussed.

  15. Andrographolide sulfonate improves Alzheimer-associated phenotypes and mitochondrial dysfunction in APP/PS1 transgenic mice.

    Science.gov (United States)

    Geng, Ji; Liu, Wen; Xiong, Yuyun; Ding, Hongqun; Jiang, Chunhong; Yang, Xiaoling; Li, Xiang; Elgehama, Ahmed; Sun, Yang; Xu, Qiang; Guo, Wenjie; Gao, Jing

    2018-01-01

    Alzheimer's disease is a neurodegenerative disorder with Amyloid-β plaques onset, synaptic damage, and cognitive decline. Aβ deposits cause pathological events including oxidative stress, mitochondrial dysfunction, and neuron death. In this study, APPswe/PSENΔ9 double transgenic mice model was used to imitate Alzheimer's disease and the effect and possible mechanism of Andrographolide sulfonate were examined. Andrographolide sulfonate was given to the mice for 7 months before the onset of Aβ plaque. Spatial memory test showed that Andrographolide sulfonate treatment prevented cognitive decline. Aβ deposits were not affected while hippocampus and synapse damage was significantly alleviated. Mechanism studies showed that oxidative stress and mitochondrial swelling was reduced after Andrographolide sulfonate administration. These findings suggest that Andrographolide sulfonate, which has been applied in clinical medicine, might be a promising therapeutic agent for AD therapy via mitochondria protection. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  16. Synthesis and Characterization of Two Sulfonated Resorcinarenes: A New Example of a Linear Array of Sodium Centers and Macrocycles

    Directory of Open Access Journals (Sweden)

    Edilma Sanabria

    2015-05-01

    Full Text Available Two sulfonated resorcinarenes were synthesized by reacting C-tetra(butyl resorcinarene or C-tetra(2-(methylthioethylresorcinarene with formaldehyde in the presence of sodium sulfite. Their structures were determined via FT-IR, 1H-NMR, 13C-NMR and mass spectrometry. Thermal gravimetric analyses of the derivatives were also carried out and revealed the presence of water molecules in the solid state. The sulfonated product of C-tetra(butylresorcinarene was characterized by an X-ray crystal structure determination. The asymmetric unit contains eight molecules of water and two of acetone, and analysis indicated that sulfonated resorcinarene prefers a cone configuration (rccc conformation in the solid state. In the crystal array, classical hydrogen bond interactions O-H···O and intermolecular contacts were observed. In the crystal packing, a linear array of capsules of sulfonated resorcinarenes was generated for a chain of sodium atoms and sulfonate groups.

  17. Alquilbenzeno sulfonato linear: uma abordagem ambiental e analítica

    Directory of Open Access Journals (Sweden)

    José Carlos P. Penteado

    2006-10-01

    Full Text Available The environmental impact of detergents and other consumer products is behind the continued interest in the chemistry of the surfactants used. Of these, linear alkylbenzene sulfonates (LASs are most widely employed in detergent formulations. The precursors to LASs are linear alkylbenzenes (LABs. There is also interest in the chemistry of these hydrocarbons, because they are usually present in commercial LASs (due to incomplete sulfonation, or form as one of their degradation products. Additionally, they may be employed as molecular tracers of domestic waste in the aquatic environment. The following aspects are covered in the present review: The chemistry of surfactants, in particular LAS; environmental impact of the production of LAS; environmental and toxicological effects of LAS; mechanisms of removal of LAS in the environment, and methods for monitoring LAS and LAB, the latter in domestic wastes. Classical and novel analytical methods employed for the determination of LAS and LAB are discussed in detail, and a brief comment on detergents in Brazil is given.

  18. Alquilbenzeno sulfonato linear: uma abordagem ambiental e analítica

    Directory of Open Access Journals (Sweden)

    Penteado José Carlos P.

    2006-01-01

    Full Text Available The environmental impact of detergents and other consumer products is behind the continued interest in the chemistry of the surfactants used. Of these, linear alkylbenzene sulfonates (LASs are most widely employed in detergent formulations. The precursors to LASs are linear alkylbenzenes (LABs. There is also interest in the chemistry of these hydrocarbons, because they are usually present in commercial LASs (due to incomplete sulfonation, or form as one of their degradation products. Additionally, they may be employed as molecular tracers of domestic waste in the aquatic environment. The following aspects are covered in the present review: The chemistry of surfactants, in particular LAS; environmental impact of the production of LAS; environmental and toxicological effects of LAS; mechanisms of removal of LAS in the environment, and methods for monitoring LAS and LAB, the latter in domestic wastes. Classical and novel analytical methods employed for the determination of LAS and LAB are discussed in detail, and a brief comment on detergents in Brazil is given.

  19. Facile synthesis of 4H-chromene derivatives via base-mediated annulation of ortho-hydroxychalcones and 2-bromoallyl sulfones

    Directory of Open Access Journals (Sweden)

    Srinivas Thadkapally

    2016-01-01

    Full Text Available The cesium carbonate-mediated reaction of 2-bromoallyl sulfones and ortho-hydroxychalcones furnished 3-arylsulfonyl-4H-chromene derivatives in 58–67% yield (18 examples. 2-Bromoallyl sulfones functioned as synthetic surrogates for allenyl sulfones in the reaction.

  20. Influence of degree of sulfonation of BDPP upon enantioselectivity in rhodium-BDPP catalyzed hydrogenation reactions in a two phase system

    NARCIS (Netherlands)

    Lensink, Cornelis; Rijnberg, Evelien; Vries, Johannes G. de

    1997-01-01

    Asymmetric hydrogenation experiments were carried out with catalysts prepared in situ from [Rh(COD)Cl]2 and 2 eq. of a sulfonated (2S,4S)-bis-2,4-(diphenylphosphino)pentane carrying 0-4 sulfonate groups, in a two phase aqueous organic system. The effect of degree of sulfonation on enantioselectivity

  1. Occurrence of alachlor and its sulfonated metabolite in rivers and reservoirs of the midwestern United States: The importance of sulfonation in the transport of chloroacetanilide herbicides

    Science.gov (United States)

    Thurman, E.M.; Goolsby, D.A.; Aga, D.S.; Pomes, M.L.; Meyer, M.T.

    1996-01-01

    Alachlor and its metabolite, 2-[(2',6'-diethylphenyl)- (methoxymethyl)amino]-2-oxoethanesulfonate (ESA), were identified in 76 reservoirs in the midwestern United States using immunoassay, liquid chromatography, and gas chromatography/mass spectrometry. The median concentration of ESA (0.48 ??g/L) exceeded the median concentration of alachlor (sulfonic acid metabolites of other chloroacetanilides, including acetochlor, butachlor, metolachlor, and propachlor, also occur in surface water.

  2. Graft-crosslinked copolymers based on poly(arylene ether ketone)-gc-sulfonated poly(arylene ether sulfone) for PEMFC applications.

    Science.gov (United States)

    Zhang, Xuan; Hu, Zhaoxia; Luo, Linqiang; Chen, Shanshan; Liu, Jianmei; Chen, Shouwen; Wang, Lianjun

    2011-07-15

    Novel poly(arylene ether ketone) polymers with fluorophenyl pendants and phenoxide-terminated wholly sulfonated poly(arylene ether sulfone) oligomers are prepared via Ni(0)-catalyzed and nucleophilic polymerization, respectively, and subsequently used as starting materials to obtain graft-crosslinked membranes as polymer electrolyte membranes. The phenoxide-terminated sulfonated moieties are introduced as hydrophilic parts as well as crosslinking units. The chemical structure and morphology of the obtained membranes are confirmed by (1) H NMR and tapping-mode AFM. The properties required for fuel cell applications, including water uptake and dimensional change, as well as proton conductivity, are investigated. AFM results show a clear nanoscale phase-separation microstructure of the obtained membranes. The membranes show good dimensional stability and reasonably high proton conductivities under 30-90% relative humidity. The anisotropic proton conductivity ratios (σ(formula see text) ) of the membranes in water are in the range 0.65-0.92, and increase with an increase in hydrophilic block length. The results indicate that the graft-crosslinked membranes are promising candidates for applications as polymer electrolyte membranes. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Las lenguas en las sociedades del conocimiento

    Directory of Open Access Journals (Sweden)

    Álvarez, J. Francisco

    2008-12-01

    Full Text Available Languages become a strategic resource for information and knowledge societies. By expressing and sharing knowledge by means of languages, every culture generates deposits of knowledge, which can be transferred and exchanged among different epistemic communities. The contemporary technologies of information and communication have changed the structure of knowledge flows. Globalization of knowledge poses a great challenge to every language, including the Spanish one. In order to survive in the digital world, they should develop technolanguages. The lemma “Thinking in Spanish” implies a new model of governance for the Ibero-American knowledge communities.En las sociedades de la información y el conocimiento las lenguas se convierten en un recurso estratégico. Al expresar y compartir conocimiento por medio de los idiomas, las culturas generan yacimientos de conocimiento, que pueden ser transferidos e intercambiados entre comunidades epistémicas diferentes. Las actuales tecnologías de la información y la comunicación han cambiado la estructura de los flujos de conocimiento. La globalización del conocimiento plantea un gran desafío a todas las lenguas, incluyendo la española. Para sobrevivir en el mundo digital, los lenguajes han de convertirse en tecnolenguajes. El lema “Pensar en español” aporta un nuevo modelo de gobernanza para las comunidades iberoamericanas del conocimiento.

  4. Gene expression profiling identifies mechanisms of protection to recurrent trinitrobenzene sulfonic acid colitis mediated by probiotics

    NARCIS (Netherlands)

    Mariman, R.; Kremer, S.H.A.; Erk, M. van; Lagerweij, T.; Koning, F.; Nagelkerken, L.

    2012-01-01

    Background: Host-microbiota interactions in the intestinal mucosa play a major role in intestinal immune homeostasis and control the threshold of local inflammation. The aim of this study was to evaluate the efficacy of probiotics in the recurrent trinitrobenzene sulfonic acid (TNBS)-induced colitis

  5. Characterisation of perfluorooctane sulfonate (PFOS) in a terrestrial ecosystem near a fluorochemical plant in Flanders, Belgium

    NARCIS (Netherlands)

    D'Hollander, W.; De Bruyn, L.; Hagenaars, A; de Voogt, P.; Bervoets, L.

    2014-01-01

    Bioaccumulation of perfluorooctane sulfonate (PFOS) in a restricted terrestrial food chain was investigated with the omnivorous wood mouse (Apodemus sylvaticus) on top of the studied food chain. The levels detected are very high compared with literature as a result of the presence of fluorochemical

  6. Transfer of perfluorooctane sulfonic acid (PFOS) from contaminated feed to dairy milk

    NARCIS (Netherlands)

    Asselt, van E.D.; Kowalczyk, J.; Eijkeren, J.C.H.; Zeilmaker, M.J.; Ehlers, S.; Fürst, P.; Lahrssen - Wiederholt, M.; Fels-Klerx, van der H.J.

    2013-01-01

    Dietary intake is the predominant route for human exposure to perfluorooctane sulfonic acid (PFOS). Single pollution events may thus affect human exposure if polluted ground and water is used to produce animal feed or food. In this study, a physiologically based pharmacokinetic (PBPK-) model is

  7. Sulfonation of cPTFE Film grafted Styrene for Proton Exchange Membrane Fuel Cell

    Directory of Open Access Journals (Sweden)

    Yohan Yohan

    2010-10-01

    Full Text Available Sulfonation of γ-ray iradiated and styrene-grafted crosslinked polytetrafluoroethylene film (cPTFE-g-S film have been done. The aim of the research is to make hydropyl membrane as proton exchange membrane fuel cell. Sulfonation was prepared with chlorosulfonic acid in chloroethane under various conditions. The impact of the percent of grafting, the concentration of chlorosulfonic acid, the reaction time,and the reaction temperature on the properties of sulfonated film is examinated. The results show that sulfonation of surface-grafted films is incomplete at room  temperature. The increasing of concentration of chlorosulfonic acid and reaction temperature accelerates the reaction but they also add favor side reactions. These will lead to decreasing of the ion-exchange capacity, water uptake, and proton conductivity but increasing the resistance to oxidation in a perhidrol solution. The cPTFE-g-SS membrane which is resulted has stability in a H2O2 30% solution for 20 hours.

  8. Sodium polyanethole sulfonate as an inhibitor of activation of complement function in blood culture systems

    DEFF Research Database (Denmark)

    Palarasah, Yaseelan; Skjoedt, Mikkel-Ole; Vitved, Lars

    2010-01-01

    Sodium polyanethole sulfonate (SPS; trade name, Liquoid) is a constituent in culture media used to grow bacteria from blood samples from patients suspected of bacteremia. SPS prevents the killing of bacteria by innate cellular and humoral factors. We analyzed the effect of SPS on the three...

  9. Water contentwater of determination of cationic polystyrene sulfonate resins by infrared spectrophotometry

    International Nuclear Information System (INIS)

    Noki, V.

    1987-01-01

    A method of the determination of water content in polystyrene sulfonate ion-exchange resins in the presence of alkaline earth counter-ions by I.R. spectrophotometry is proposed. This method does not hold in the case of transition metal due to the formation of coordinated complexes with water molecules.

  10. Effect of mixed-sulfonated aluminium phthalocyanine on human skin fibroblasts for photodynamic therapy

    CSIR Research Space (South Africa)

    Ndhundhuma, IM

    2008-08-01

    Full Text Available of the study was to evaluate the effect of mixed-sulfonated aluminium phthalocyanine (AlPcSmix) used as photosensitizers for PDT, determined by changes in cell morphology and cell viability of human skin fibroblasts (WS1). Methods. Cells incubated with 5, 10...

  11. Wine metabolomics reveals new sulfonated products in bottled white wines, promoted by small amounts of oxygen.

    Science.gov (United States)

    Arapitsas, Panagiotis; Ugliano, Maurizio; Perenzoni, Daniele; Angeli, Andrea; Pangrazzi, Paolo; Mattivi, Fulvio

    2016-01-15

    The impact of minute amounts of oxygen in the headspace on the post-bottling development of wine is generally considered to be very important, since oxygen can either damage or improve the quality of wine. This project aimed to gain new experimental evidence about the chemistry of the interaction between wine and oxygen. The experimental design included 216 bottles of 12 different white wines produced from 6 different cultivars (Inzolia, Muller Thurgau, Chardonnay, Grillo, Traminer and Pinot gris). Half of them were bottled using the standard industrial process with inert headspace and the other half without inert gas and with extra headspace. After 60 days of storage at room temperature, the wines were analysed using an untargeted LC-MS method. The use of a detailed holistic analysis workflow, with several levels of quality control and marker selection, gave 35 metabolites putatively induced by the different amounts of oxygen. These metabolite markers included ascorbic acid, tartaric acid and various sulfonated compounds observed in wine for the first time (e.g. S-sulfonated cysteine, glutathione and pantetheine; and sulfonated indole-3-lactic acid hexoside and tryptophol). The consumption of SO2 mediated by these sulfonation reactions was promoted by the presence of higher levels of oxygen on bottling. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Demarcation of mutant-carrying regions in barley plants after ethylmethane-sulfonate seed treatment

    DEFF Research Database (Denmark)

    Jacobsen, P.

    1966-01-01

    The branching pattern of the barley plant is analyzed and the anatomical structure of the resting barley embryo studied in longitudinal and cross-sections as well as by dissection techniques. The frequency and distribution of ethylmethane-sulfonate induced chloroplast and morphological seedling...

  13. Multi-block sulfonated poly(phenylene) copolymer proton exchange membranes

    Science.gov (United States)

    Fujimoto, Cy H [Albuquerque, NM; Hibbs, Michael [Albuquerque, NM; Ambrosini, Andrea [Albuquerque, NM

    2012-02-07

    Improved multi-block sulfonated poly(phenylene) copolymer compositions, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cells, in electrode casting solutions and electrodes. The multi-block architecture has defined, controllable hydrophobic and hydrophilic segments. These improved membranes have better ion transport (proton conductivity) and water swelling properties.

  14. FT-IR SOLUTION SPECTRA OF PROPYL SULFIDE, PROPYL SULFOXIDE, AND PROPYL SULFONE

    Science.gov (United States)

    FT-IR spectra were obtained of 0.5% volumetric solutions of propyl sulfide, propyl sulfoxide, and propyl sulfone in hexane, CCl4, CS2, and CHCl3 to assist in the assignment of FT-IR-PAS spectra of propyl sulfoxide sorbed within the structure of several peats and onto cellulose. T...

  15. Sulfonate-grafted porous polymer networks for preferential CO(2) adsorption at low pressure

    NARCIS (Netherlands)

    Lu, W.; Yuan, D.; Sculley, J.; Zhao, D.; Krishna, R.; Zhou, H.-C.

    2011-01-01

    A porous polymer network (PPN) grafted with sulfonic acid (PPN-6-SO3H) and its lithium salt (PPN-6-SO3Li) exhibit significant increases in isosteric heats of CO2 adsorption and CO2-uptake capacities. IAST calculations using single-component-isotherm data and a 15/85 CO2/N2 ratio at 295 K and 1 bar

  16. 40 CFR 721.9674 - Sulfonated-copper phthalocyanine salt of a triarylmethane dye (generic).

    Science.gov (United States)

    2010-07-01

    ... of a triarylmethane dye (generic). 721.9674 Section 721.9674 Protection of Environment ENVIRONMENTAL... triarylmethane dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as sulfonated-copper phthalocyanine salt of a triarylmethane dye...

  17. Camphorquinone-10-sulfonic acid and derivatives: convenient reagents for reversible modification of arginine residues.

    Science.gov (United States)

    Pande, C S; Pelzig, M; Glass, J D

    1980-02-01

    Camphorquinone-10-sulfonic acid hydrate was prepared by the action of selenous acid on camphor-10-sulfonic acid. Camphorquinone-10-sulfonylnorleucine was prepared either from the sulfonic acid via the sulfonyl chloride or by selenous acid oxidation of camphor-10-sulfonylnorleucine. These reagents are useful for specific, reversible modification of the guanidino groups of arginine residues. Camphorquinonesulfonic acid is a crystalline water-soluble reagent that is especially suitable for use with small arginine-containing molecules, because the sulfonic acid group of the reagent is a convenient handle for analytical and preparative separation of products. Camphorquinonesulfonylnorleucine is more useful for work with large polypeptides and proteins, because hydrolysates of modified proteins may be analyzed for norleucine to determine the extent of arginine modification. The adducts of the camphorquinone derivatives with the guanidino group are stable to 0.5 M hydroxylamine solutions at pH 7, the recommended conditions for cleavage of the corresponding cyclohexanedione adducts. At pH 8-9 the adducts of the camphorquinone derivatives with the guanidino group are cleaved by o-phenylenediamine. The modification and regeneration of arginine, of the dipeptide arginylaspartic acid, of ribonuclease S-peptide, and of soybean trypsin inhibitor are presented as demonstrations of the use of the reagents. The use of camphorquinonesulfonyl chloride to prepare polymers containing arginine-specific ligands is discussed.

  18. Sulfonated graphene oxide as effective catalyst for conversion of 5-(hydroxymethyl)-2-furfural into biofuels.

    Science.gov (United States)

    Antunes, Margarida M; Russo, Patrícia A; Wiper, Paul V; Veiga, Jacinto M; Pillinger, Martyn; Mafra, Luís; Evtuguin, Dmitry V; Pinna, Nicola; Valente, Anabela A

    2014-03-01

    The acid-catalyzed reaction of 5-(hydroxymethyl)-2-furfural with ethanol is a promising route to produce biofuels or fuel additives within the carbohydrate platform; specifically, this reaction may give 5-ethoxymethylfurfural, 5-(ethoxymethyl)furfural diethylacetal, and/or ethyl levulinate (bioEs). It is shown that sulfonated, partially reduced graphene oxide (S-RGO) exhibits a more superior catalytic performance for the production of bioEs than several other acid catalysts, which include sulfonated carbons and the commercial acid resin Amberlyst-15, which has a much higher sulfonic acid content and stronger acidity. This was attributed to the cooperative effects of the sulfonic acid groups and other types of acid sites (e.g., carboxylic acids), and to the enhanced accessibility to the active sites as a result of the 2D structure. Moreover, the acidic functionalities bonded to the S-RGO surface were more stable under the catalytic reaction conditions than those of the other solids tested, which allowed its efficient reuse. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Antibacterial surface modified of novel nanocomposite sulfonated polyethersulfone/polyrhodanine membrane

    Science.gov (United States)

    Rostam, Abbas Babaei; Peyravi, Majid; Ghorbani, Mohsen; Jahanshahi, Mohsen

    2018-01-01

    In this study, sulfonated-polyethersulfone/polyrhodanine (SPES/PRh) membranes with antibacterial behavior were fabricated. Polyethersulfone (PES) sulfonation was performed to enhance its hydrophilicity and next polyrhodanine nanoparticles (PRhNPs) were synthesized along with the sulfonated PES (SPES) by polyrhodanine (PRh) in situ polymerization. The sulfonation step also helps making composite membrane due to development of probable bondings and polymers engagements. The constructed membranes characterization was performed by FTIR, FESEM, contact angle, 1H NMR, TGA and EDS analyses. SPES/PRh membrane had enhanced hydrophilicity and consequently better fluxes for aqueous solutions. The composite SPES/PRh membrane flux was improved to 139/78 L/m2 h comparing 58.21 L/m2 h for SPES one. Membrane operational performances, antibacterial and antibiofouling tests showed improved flux, better rejection and appropriate antibacterial and antibiofouling properties for SPES/PRh membrane. The 100% bacteria mortality for specified concentrations and appropriate inhibition zones up to 9 mm have been achieved. It is generally a suitable membrane to provide proper performance beside antibacterial and antibiofouling behavior.

  20. Sulfonated poly(ether ether ketone) based composite membranes for nanofiltration of acidic and alkaline media

    NARCIS (Netherlands)

    Dalwani, M.R.; Bargeman, Gerrald; Hosseiny, Seyed Schwan; Schwan Hosseiny, Seyed; Boerrigter, M.E.; Wessling, Matthias; Benes, Nieck Edwin

    2011-01-01

    Several thin film composite nanofiltration membranes have been prepared by spin coating a sulfonated poly(ether ether ketone) solution on a polyethersulfone support, followed by thermal treatment. The most optimal developed nanofiltration membrane shows a clean water permeance of ∼4.5 L m−2 h−1

  1. Copper(I)-catalyzed olefination of N-sulfonylhydrazones with sulfones.

    Science.gov (United States)

    Xu, Shuai; Gao, Yunpeng; Chen, Ri; Wang, Kang; Zhang, Yan; Wang, Jianbo

    2016-03-25

    The Cu(I)-catalyzed olefination of N-sulfonylhydrazones with sulfones via metal carbene intermediates is reported. This reaction uses readily available starting materials and is operationally simple, thus representing a practical method for the construction of carbon-carbon double bonds. Mechanistically, Cu(I) carbene formation and subsequent carbene migratory insertion are proposed as the key steps.

  2. Major sulfonate transporter Soa1 in Saccharomyces cerevisiae and considerable substrate diversity in its fungal family

    DEFF Research Database (Denmark)

    Holt, Sylvester; Kankipati, Harish; De Graeve, Stijn

    2017-01-01

    that also catalyses sulfonate and choline sulfate uptake. Phylogenetic analysis of fungal SOA1 orthologues and expression of 20 members in the sul1 Delta sul2 Delta soa1 Delta strain, which is deficient in inorganic and organic sulfur compound uptake, reveals that these transporters have diverse substrate...

  3. Condensed tannin-sulfonate derivatives in cold-setting wood-laminating adhesives

    Science.gov (United States)

    Roland E. Kreibich; Richard W. Hemingway

    1987-01-01

    Extraction of southern pine bark with 4.0 percent sodium sulfite and 0.4-percent sodium carbonate(based on ovendry bark weight) gives epicatechin-(4β)-sulfonate and oligomeric procyanidin-4-sulfonatee that show great promise to replace about 50 percent of the phenol-resorcinol-formaldehyde resin in coldsetting wood-laminating adhesives. Bonds in Douglas-fir...

  4. Heterogeneous ion-exchange membranes based on sulfonated poly(1,4-phenylene sulfide)

    Czech Academy of Sciences Publication Activity Database

    Schauer, Jan; Kůdela, Vlastimil; Richau, K.; Mohr, R.

    2006-01-01

    Roč. 198, 1-3 (2006), s. 256-264 ISSN 0011-9164 R&D Projects: GA ČR GA203/05/0080 Institutional research plan: CEZ:AV0Z40500505 Keywords : poly(1,4-phenylene sulfide) sulfonated * ion-exchange membrane Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.917, year: 2006

  5. Synthesis of highly sulfonated polystyrene-based block copolymers soluble in tetrahydrofuran

    Czech Academy of Sciences Publication Activity Database

    Janata, Miroslav; Kůdela, Vlastimil; Gromadzki, D.; Štěpánek, Petr; Nallet, F.; Diat, O.; Vlček, Petr; Toman, Luděk

    55, - (2006), 1-12 ISSN 1618-7229 R&D Projects: GA ČR GESON/03/E001 Institutional research plan: CEZ:AV0Z40500505 Keywords : polystyrene-block-hydrogenated polyisoprene * sulfonation * acetyl sulfate Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.934, year: 2006 www.e-polymers.org

  6. Synthesis of Highly Sulfonated Poly(arylene ether Containing Multiphenyl for Proton Exchange Membrane Materials

    Directory of Open Access Journals (Sweden)

    Yi-Chiang Huang

    2016-01-01

    Full Text Available A series of sterically hindered, sulfonated, poly(arylene ether polymers were synthesized by nucleophilic polycondensation reaction using 4,4′′′′-difluoro-3,3′′′′-bistrifluoromethyl-2′′,3′′,5′′,6′′-tetraphenyl-[1,1′;4′,1′′;4′′,1′′′;4′′′,1′′′′]-pentaphenyl and 4,4′-biphenol and were prepared through postpolymerization sulfonation. The chemical structures were confirmed by 1H NMR. Subsequent to sulfonation, solvent-casting membranes were provided ion exchange capacity (IEC values ranging from 0.39 to 2.90 mmol/g. Proton conductivities of membranes ranged from 143 to 228 mS/cm at 80°C under fully humidified conditions which were higher than that of Nafion 117. The membrane also exhibited considerably dimension stability, oxidative stability, and hydrolytic stability. The microphase structure was investigated by transmission electron microscopy (TEM and the ionic aggregation of sulfonic acid groups exhibited spherical ionic clusters with well-developed phase separated morphology. The results indicated that the membranes are promising candidates for application as proton exchange membranes. This investigation demonstrates introducing multiphenylated moieties to create a high free volume polymer that provides dimensionally stable and high proton conductivity membranes.

  7. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, Beata; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds

  8. 78 FR 62443 - Perfluoroalkyl Sulfonates and Long-Chain Perfluoroalkyl Carboxylate Chemical Substances; Final...

    Science.gov (United States)

    2013-10-22

    ... various components of the LCPFAC category definition. 5. Comment summary. A submitter suggested that 40... gathering information from suppliers along the supply chain, and/or testing samples of the article itself... 2070-AJ95 Perfluoroalkyl Sulfonates and Long-Chain Perfluoroalkyl Carboxylate Chemical Substances...

  9. Sulfonation of environmental chemicals and their metabolites in the polar bear (Ursus maritimus).

    Science.gov (United States)

    Sacco, James C; James, Margaret O

    2005-09-01

    Although its habitat comprises mostly remote regions of the Arctic, the polar bear is subject to bioaccumulation of persistent environmental pollutants. Along with their phase I metabolites, they are potential substrates for detoxification via sulfonation and glucuronidation. The capability of polar bear liver to sulfonate a structurally diverse group of environmental chemicals, that is, 3-hydroxybenzo[a]pyrene (3-OH-B[a]P), triclosan, 4'-hydroxy-3,3',4,5'-tetrachlorobiphenyl (4'OH-PCB79), 4'-hydroxy-2,3,3',4,5,5'-hexachlorobiphenyl (4'-OH-PCB159), 4'-hydroxy-2,3,3',5,5',6-hexachlorobiphenyl (4'-OH-PCB165), the methoxychlor metabolite 2-(4-methoxyphenyl)-2-(4-hydroxyphenyl)-1,1,1-trichloroethane (OHMXC), tris(4-chlorophenyl)-methanol (TCPM), and pentachlorophenol (PCP) was investigated. The glucuronidation of 3-OH-B[a]P was also studied. Enzyme activity was assayed by incubation of liver cytosol or microsomes derived from three adult male polar bears with 3'-phosphoadenosine-5'-phosphosulfate or uridine 5'-diphosphoglucuronic acid and substrate, followed by fluorometric or radiochemical thin-layer chromatographic analysis. The efficiency of sulfonation decreased in the order 3-OH-B[a]P > triclosan > 4'-OH-PCB79 > OHMXC > 4'-OH-PCB165 > TCPM > 4'-OH-PCB159 > PCP, all of which produced detectable sulfate conjugates. The 3-OH-B[a]P substrate was readily sulfonated and glucuronidated (apparent K(m) 0.41, 1.4 microM, and apparent V(max) 0.50, 3.00 nmol/min/mg, respectively). UDP-glucuronic acid kinetics suggested the presence of multiple enzymes glucuronidating 3-OH-B[a]P. Substrate inhibition was observed for the sulfonation of 3-OH-B[a]P and 4'OH-PCB79 (K(i) 1.0 and 217 microM, respectively). Triclosan was the most rapidly sulfated (apparent V(max) 1008 pmol/min/mg) of the substrates tested. Since sulfonation of an acyclic tertiary alcoholic group, as in TCPM, has not previously been reported, we also examined TCPM conjugation in humans and catfish, both of which

  10. Synthesis of sulfonated porous carbon nanospheres solid acid by a facile chemical activation route

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Binbin, E-mail: changbinbin806@163.com; Guo, Yanzhen; Yin, Hang; Zhang, Shouren; Yang, Baocheng, E-mail: baochengyang@yahoo.com

    2015-01-15

    Generally, porous carbon nanospheres materials are usually prepared via a template method, which is a multi-steps and high-cost strategy. Here, we reported a porous carbon nanosphere solid acid with high surface area and superior porosity, as well as uniform nanospheical morphology, which prepared by a facile chemical activation with ZnCl{sub 2} using resorcinol-formaldehyde (RF) resins spheres as precursor. The activation of RF resins spheres by ZnCl{sub 2} at 400 °C brought high surface area and large volume, and simultaneously retained numerous oxygen-containing and hydrogen-containing groups due to the relatively low processing temperature. The presence of these functional groups is favorable for the modification of –SO{sub 3}H groups by a followed sulfonation treating with sulphuric acid and organic sulfonic acid. The results of N{sub 2} adsorption–desorption and electron microscopy clearly showed the preservation of porous structure and nanospherical morphology. Infrared spectra certified the variation of surface functional groups after activation and the successful modification of –SO{sub 3}H groups after sulfonation. The acidities of catalysts were estimated by an indirect titration method and the modified amount of –SO{sub 3}H groups were examined by energy dispersive spectra. The results suggested sulfonated porous carbon nanospheres catalysts possessed high acidities and –SO{sub 3}H densities, which endowed their significantly catalytic activities for biodiesel production. Furthermore, their excellent stability and recycling property were also demonstrated by five consecutive cycles. - Graphical abstract: Sulfonated porous carbon nanospheres with high surface area and superior catalytic performance were prepared by a facile chemical activation route. - Highlights: • Porous carbon spheres solid acid prepared by a facile chemical activation. • It owns high surface area, superior porosity and uniform spherical morphology. • It possesses

  11. Copoly(arylene ether)s containing pendant sulfonic acid groups as proton exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Dae Sik, Kim [Los Alamos National Laboratory; Yu Seung, Kim [Los Alamos National Laboratory; Gilles, Robertson [CANADA-NRC; Guiver, Michael D [CANADA-NRC

    2009-01-01

    A copoly(arylene ether) (PAE) with high fluorine content and a copoly(arylene ether nitrile) (PAEN) with high nitrile content, each containing pendant phenyl sulfonic acids were synthesized. The PAE and P AEN were prepared from decafluorobiphenyl (DFBP) and difluorobenzonitrile (DFBN) respectively, by polycondensation with 2phenylhydroquinone (PHQ) by conventional aromatic nucleophilic substitution reactions. sulfonic acid groups were introduced by mild post-sulfonation exclusively on the para-position of the pendant phenyl ring in PHQ. The membrane properties of the resulting sulfonated copolymers sPAE and sPAEN were compared for fuel cell applications. The copolymers sPAE and sPAEN, each having a degree of sulfonation (OS) of 1.0 had high ion exchange capacities (IEC{sub v})(wet) (volume-based, wet state) of 1.77 and 2.55 meq./cm3, high proton conductivities of 135.4 and 140.1 mS/cm at 80 C, and acceptable volume-based water uptake of 44.5 -51.9 vol% at 80 C, respectively, compared to Nafion. The data points of these copolymer membranes are located in the upper left-hand corner in the trade-off plot of alternative hydrocarbon polyelectrolyte membranes (PEM) for the relationship between proton conductivity versus water uptake (weight based or volume based), i.e., high proton conductivity and low water uptake. Furthermore, the relative selectivity derived from proton conductivity and methanol permeability is higher than that of Nafion.

  12. Controllable sulfonation of aromatic poly(arylene ether ketone)s containing different pendant phenyl rings

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhiliang; Liu, Xincai; Chao, Danming; Zhang, Wanjin [Alan G. MacDiarmid Institute, Jilin University, Qianjin Street 2699, Changchun 130012 (China)

    2009-09-05

    The sulfonation selectivity of various pendant phenyl groups in poly(arylene ether ketone) (Ph-3F-PAEK) is invested via the postsulfonation approach. The sulfonated Ph-3F-PAEKs with different degrees of sulfonation (DS) are quantitatively synthesized by controlling the length of the segments that cannot be sulfonated. In this study, {sup 1}H NMR and FT-IR are used to confirmed the structures of the polymers and the experimentally DS values were calculated by {sup 1}H NMR. The experimentally observed DSs are corresponding to the theoretical values expected from the monomer ratios. All the sulfonated membranes have excellent mechanical properties (with a Young's modulus >1.3 GPa, a tensile strength >55 MPa and the elongation >10%). Thermogravimetric analysis (TGA) is used to characterized the thermal stability of these polymers, and all the polymers show excellent thermal properties at high temperatures. The methanol permeability values of Ph-3F-SPAEKs in the range of 0.37 x 10{sup -7} cm{sup 2} s{sup -1} to 4.12 x 10{sup -7} cm{sup 2} s{sup -1} are much lower than that of Nafion {sup registered} 117 (1.55 x 10{sup -6} cm{sup 2} s{sup -1}). It should be noted that the polymer with highest DS, Ph-3F-SPAEK-100 with an ion exchange capacity of 2.16 mequiv. g{sup -1}, exhibits high proton conductivity of 0.187 S cm{sup -1} at 80 C, which is also higher than that of Nafion {sup registered} 117. (author)

  13. Identification of biotin sulfone, bisnorbiotin methyl ketone, and tetranorbiotin-l-sulfoxide in human urine.

    Science.gov (United States)

    Zempleni, J; McCormick, D B; Mock, D M

    1997-02-01

    In previous studies using the HPLC and avidin-binding assay, five unidentified avidin-binding substances were observed in human urine. The present study investigated the identity of these substances. Urine was collected before and after intravenous administration of 18.5 mumol biotin to healthy adults. Unknown substances 1 and 3 were initially identified as biotin sulfone and bisnorbiotin methyl ketone, respectively, by coelution with authentic standards on HPLC. Identities were confirmed by thin-layer chromatography and by derivatization with p-dimethyl-aminocinnamaldehyde. As expected for biotin metabolites, the urinary excretion of biotin sulfone and bisnorbiotin methyl ketone increased with biotin administration. The urinary excretion of biotin sulfone increased 21-fold from 0.2 nmol/h before to 4.2 nmol/h after administration; the excretion of bisnorbiotin methyl ketone increased 130-fold from 0.4 to 51.8 nmol/h. At presumed steady state in free-living subjects (n = 6), biotin sulfone and bisnorbiotin methyl ketone accounted for 3.6% and 7.9% of total biotin excretion, respectively. Traces of tetranorbiotin-l-sulfoxide were also identified by using thin-layer chromatography and derivatization with p-dimethylaminocinnamaldehyde. However, tetranorbiotin-l-sulfoxide was not detectable in urine by the HPLC and avidin-binding assay because this metabolite has weak avidin-binding affinity. We conclude that biotin sulfone and bisnorbiotin methyl ketone are present in measurable quantities in human urine; their quantitation should allow more accurate studies on human biotin metabolism and turnover.

  14. Asymmetric Synthesis of Diarylmethyl Sulfones by Palladium-Catalyzed Enantioselective Benzylic Substitution: A Remarkable Effect of Water.

    Science.gov (United States)

    Najib, Atifah; Hirano, Koji; Miura, Masahiro

    2018-03-25

    A Pd/(R)-BINAP-catalyzed enantioselective benzylic sulfonation of diarylmethyl carbonates with sodium sulfinates proceeds to deliver the corresponding chiral diarylmethyl sulfones in good yields with high enantioselectivity. The reaction occurs in a dynamic kinetic asymmetric transformation (DYKAT) manner and thus provides convergent access to optically active benzylic sulfones from racemic secondary benzylic carbonates. Additionally, the addition of H 2 O is found to be critical for high enantioselectivity. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Las incubadoras de las empresas de Quebec

    Directory of Open Access Journals (Sweden)

    Bernardo Parra Restrepo

    1993-01-01

    Full Text Available Este articulo contiene información de las incubadoras de empresas especialmente aquellas encontradas en Quebec. A través de los 80's, el concepto de incubadoras de empresas fue introducido en América por expertos en el desarrollo económico. Sus metas fueron el estudio de los efectos del desempleo resultante de la quiebra de plantas industriales o del uso del proceso de producción automático por parte de las grandes compañías. Además se esperaba crear empleo para los inmigrantes. El campo más prometedor de estas experiencias se encuentra en el desarrollo de alta tecnología industrial, especialmente en electrónica, microprocesadores y software para sistemas de computación. Esta área también cubre las industrias innovadoras.

  16. Catalytic performance of strong acid catalyst: Methyl modified SBA-15 loaded perfluorinated sulfonic acid obtained by the waste perfluorinated sulfonic acid ion exchange membrane

    Science.gov (United States)

    Jiang, Tingshun; Huang, Qiuyan; Li, Yingying; Fang, Minglan; Zhao, Qian

    2018-02-01

    Mesoporous molecular sieve (SBA-15) was modified using the trimethylchlorosilane as functional agent and the silylation SBA-15 mesoporous material was prepared in this work. The alcohol solution of perfluorinated sulfonic acid dissolved from the waste perfluorinated sulfonic acid ion exchange membrane (PFSIEM) was loaded onto the resulting mesoporous material by the impregnation method and their physicochemical properties were characterized by FT-IR, N2-physisorption, XRD, TG-DSC and TEM. The catalytic activities of these synthesized solid acid catalysts were evaluated by alkylation of phenol with tert-butyl alcohol. The influence of reaction temperature, weight hour space velocity (WHSV) and reaction time on the phenol conversion and product selectivity were assessed by means of a series of experiments. The results showed that with the increase of the active component of the catalyst, these catalysts still remained good mesoporous structure, but the mesoporous ordering decreased to some extent. These catalysts exhibited good catalytic performance for the alkylation of phenol with tert-butanol. The maximum phenol conversion of 89.3% with 70.9% selectivity to 4-t-butyl phenol (4-TBP) was achieved at 120 °C and the WHSV is 4 h-1. The methyl group was loaded on the surface of the catalyst by trimethylchlorosilane. This is beneficial to retard the deactivation of the catalyst. In this work, the alkylation of phenol with tert-butyl alcohol were carried out using the methyl modified SBA-15 mesoporous materials loaded perfluorinated sulfonic acid as catalysts. The results show that the resulting catalyst exhibited high catalytic activity.

  17. Sulfonation and phosphorylation of regions of the dioxin receptor susceptible to methionine modifications.

    Science.gov (United States)

    Dave, Keyur A; Whelan, Fiona; Bindloss, Colleen; Furness, Sebastian G B; Chapman-Smith, Anne; Whitelaw, Murray L; Gorman, Jeffrey J

    2009-04-01

    Tagged murine dioxin receptor was purified from mammalian cells, digested with trypsin, and analyzed by capillary HPLC-MALDI-TOF/TOF-MS and -MS/MS. Several chromatographically distinct semitryptic peptides matching two regions spanning residues Glu(409)-Arg(424) and Ser(547)-Arg(555) of the dioxin receptor were revealed by de novo sequencing. Methionine residues at 418 and 548 were detected in these peptides as either unmodified or modified by moieties of 16 (oxidation) or 57 amu (S-carboxamidomethylation) or in a form corresponding to degradative removal of 105 amu from the S-carboxamidomethylated methionine. MS/MS spectra revealed that the peptides containing modified methionine residues also existed in forms with a modification of +80 amu on serine residues 411, 415, and 547. The MS/MS spectra of these peptide ions also revealed diagnostic neutral loss fragment ions of 64, 98, and/or 80 amu, and in some instances combinations of these neutral losses were apparent. Taken together, these data indicated that serines 411 and 547 of the dioxin receptor were sulfonated and serine 415 was phosphorylated. Separate digests of the dioxin receptor were prepared in H(2)(16)O and H(2)(18)O, and enzymatic dephosphorylation was subsequently performed on the H(2)(16)O digest only. The digests were mixed in equal proportions and analyzed by capillary HPLC-MALDI-TOF/TOF-MS and -MS/MS. This strategy confirmed assignment of sulfonation as the cause of the +80-amu modifications on serines 411 and 547 and phosphorylation as the predominant cause of the +80-amu modification of serine 415. The relative quantitation of phosphorylation and sulfonation enabled by this differential phosphatase strategy also suggested the presence of sulfonation on a serine other than residue 411 within the sequence spanning Glu(409)-Arg(424). This represents the first description of post-translational sulfonation sites and identification of a new phosphorylation site of the latent dioxin receptor

  18. Analysis of perfluorinated phosponic acids and perfluorooctane sulfonic acid in water, sludge and sediment by LC-MS/MS

    NARCIS (Netherlands)

    Esperza, X.; Moyano, E.; de Boer, J.; Galceran, M.T.; van Leeuwen, S.P.J.

    2011-01-01

    Residues of perfluorinated phosphonic acids (PFPAs) and perfluorooctane sulfonic acid (PFOS) were investigated in various Dutch surface waters, sludge and sediments. For this purpose, a liquid chromatographic (LC) method was optimized by testing several columns with different mobile phases.

  19. Demographic, reproductive, and dietary determinants of perfluorooctane sulfonic (PFOS) and perfluorooctanoic acid (PFOA) concentrations in human colostrum

    NARCIS (Netherlands)

    Jusko, T.A.; Oktapodas, M.; Palkovičová Murinová, L.; Babjaková, J.; Verner, M.A.; DeWitt, J.C.; Babinská, K.; Thevenet-Morrison, K.; Čonka, K.; Drobná, B.; Thurston, S.W.; Lawrence, B.P.; Dozier, A.M.; Jarvinen-Seppo, K.M.; Patayová, H.; Trnovec, T.; Legler, J.; Hertz-Picciotto, I.; Lamoree, M.H.

    2016-01-01

    To determine demographic, reproductive, and maternal dietary factors that predict perfluoroalkyl substance (PFAS) concentrations in breast milk, we measured perfluorooctane sulfonic (PFOS) and perfluorooctanoic acid (PFOA) concentrations, using liquid chromatography-mass spectrometry, in 184

  20. Destruction of gel sulfonated cation-exchangers of the KU-2 type under the influence of hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Roginskaya, B.S.; Zavadovskaya, A.S.; Znamenskii, Yu.P.; Paskhina, N.A.; Dobrova, E.I.

    1988-10-20

    The purpose of this work was to study the mechanism of interaction of Soviet sulfonated cation-exchangers of the KU-2 type with hydrogen peroxide. It is shown that under the influence of hydrogen peroxide sulfonated cation-exchangers begin, after a certain induction period, to lose capacity and to release destruction products into water; the length of the induction period increases with the degree of cross-linking. In a given time of contact between the resin and the solution the degree of destruction falls with increase of cross-linking. The principal product of destruction of sulfonated cation-exchangers is an aromatic sulfonic acid containing oxidized groups in the side chains.

  1. Beta,beta-Disilylated Sulfones as Versatile Building Blocks in Organic Chemistry – A New Sulfonyl Carbanion Transmetalation

    Czech Academy of Sciences Publication Activity Database

    Puget, Bertrand; Jahn, Ullrich

    -, č. 17 (2010), s. 2579-2582 ISSN 0936-5214 Institutional research plan: CEZ:AV0Z40550506 Keywords : carbanions * transmetalation * silanes * sulfones * Julia olefination Subject RIV: CC - Organic Chemistry Impact factor: 2.447, year: 2010

  2. High Ion-Exchange Capacity Semihomogeneous Cation Exchange Membranes Prepared via a Novel Polymerization and Sulfonation Approach in Porous Polypropylene.

    Science.gov (United States)

    Jiang, Shanxue; Ladewig, Bradley P

    2017-11-08

    Semihomogeneous cation exchange membranes with superior ion exchange capacity (IEC) were synthesized via a novel polymerization and sulfonation approach in porous polypropylene support. The IEC of membranes could reach up to 3 mmol/g because of high mass ratio of functional polymer to membrane support. Especially, theoretical IEC threshold value agreed well with experimental threshold value, indicating that IEC could be specifically designed without carrying out extensive experiments. Also, sulfonate groups were distributed both on membrane surface and across the membranes, which corresponded well with high IEC of the synthesized membranes. In addition, the semifinished membrane showed hydrophobic property because of the formation of polystyrene. In contrast, the final membranes demonstrated super hydrophilic property, indicating the adequate sulfonation of polystyrene. Furthermore, when sulfonation reaction time increased, the conductivity of membranes also showed a tendency to increase, revealing the positive relationship between conductivity and IEC. Finally, the final membranes showed sufficient thermal stability for electrodialysis applications such as water desalination.

  3. Surface Structural Studies of Methane Sulfonic Acid at Air/Aqueous Solution Interfaces using Vibrational Sum Frequency Spectroscopy

    National Research Council Canada - National Science Library

    Allen, H

    2000-01-01

    Atmospheric gas phase species such as methane sulfonic acid (MSA) are adsorbed and accommodated into atmospheric aqueous-phase aerosols and in some cases MSA is thought to be produced via aerosol surface chemistry...

  4. Las calculadoras en las clases de matemáticas

    OpenAIRE

    Mora, José

    1994-01-01

    Las calculadoras han entrado en las clases de matemáticas para ocupar un espacio que les ha permitido convertirse en una herramienta natural. Los estudiantes las utilizan con desparpajo y el profesorado las ve ya con menor recelo. Las calculadoras realizan con facilidad ciertas tareas rutinarias.

  5. Mixed-component sulfone-sulfoxide tagged zinc IRMOFs:In situ ligand oxidation, carbon dioxide, and water sorption studies

    OpenAIRE

    Bryant, Macguire R; Burrows, Andrew D; Kepert, Cameron J; Southon, Peter D; Qazvini, Omid T; Telfer, Shane G; Richardson, Christopher

    2017-01-01

    Reported here are the syntheses and adsorption properties of a series of single- and mixed-component zinc IRMOFs derived from controlled ratios of sulfide and sulfone functionalized linear biphenyldicarboxylate (bpdc) ligands. During MOF synthesis the sulfide moieties undergo in situ oxidation, giving rise to sulfoxide functionalized ligands, which are incorporated to give mixed-component sulfoxide–sulfone functionalized MOFs. The single- and mixed-component systems all share the IRMOF-9 stru...

  6. Enzymatic treatment of sulfonated aromatic amines generated from reductive degradation of reactive azo dyes.

    Science.gov (United States)

    Biswas, Mousumi Mani; Taylor, Keith E; Bewtra, Jatinder K; Biswas, Nihar

    2007-04-01

    Anaerobic degradation, an effective treatment process of textile industry effluent, generates sulfonated aromatic amines, which are carcinogenic, mutagenic, and resistant to microbial degradation. These aromatic amines can be effectively removed by oxidative polymerization catalyzed by peroxidase enzyme. The amines, generated in this study from the anaerobic reduction by zero-valent iron of two reactive azo dyes (Reactive Red 2 [RR2] and Reactive Black 5 [RB5]), were successfully removed (90%) by Arthromyces ramosus peroxidase (ARP). For better understanding of the process, enzymatic treatment of two model compounds, diphenylamine (DPA) and 2-amino-8-naphthol-3,6-disulfonic acid (ANDSA), were also studied. Diphenylamine has a similar diarylamine bond as RR2. The ANDSA has a similar structure as the dye reduction products. The secondary amine bond in DPA and RR2 were oxidized by ARP. Enzymatic reaction of sulfonated aromatic amines generated soluble colored compounds, which were removed by coagulant. Optimum reaction parameters were also determined.

  7. Controlled disulfonated poly(arylene ether sulfone) multiblock copolymers for direct methanol fuel cells.

    Science.gov (United States)

    Li, Qing; Chen, Yu; Rowlett, Jarrett R; McGrath, James E; Mack, Nathan H; Kim, Yu Seung

    2014-04-23

    Structure-property-performance relationships of disulfonated poly(arylene ether sulfone) multiblock copolymer membranes were investigated for their use in direct methanol fuel cell (DMFC) applications. Multiple series of reactive polysulfone, polyketone, and polynitrile hydrophobic block segments having different block lengths and molecular composition were synthesized and reacted with a disulfonated poly(arylene ether sulfone) hydrophilic block segment by a coupling reaction. Large-scale morphological order of the multiblock copolymers evolved with the increase of block size that gave notable influence on mechanical toughness, water uptake, and proton/methanol transport. Chemical structural changes of the hydrophobic blocks through polar group, fluorination, and bisphenol type allowed further control of the specific properties. DMFC performance was analyzed to elicit the impact of structural variations of the multiblock copolymers. Finally, DMFC performances of selected multiblock copolymers were compared against that of the industrial standard Nafion in the DMFC system.

  8. Proton-Conducting Sulfonated Ionomers by Chemical Modification and Atom Transfer Radical Polymerization

    DEFF Research Database (Denmark)

    Nielsen, Mads Møller

    to the conservation of mechanical stability. The morphology of these blends is affected by the PVDF content. At 25 vol% ionomer macro-phase-separation occurs, while a 40 vol% ionomer content on top of the macro-phase-separation develops a repetitive patten of ion-rich domains in primarily PVDF-containing areas...... (PEM) and thereby optimizing their properties. Equally important has been the evolution of model systems that are part of a bigger research perspective as well as the application of unconventional strategies within the field. In the design of amphiphilic polymers, a commercially available polysulfone...... (PSU), Udel, is chosen as backbone due to its mechanical and thermal properties. Sulfonic acid functionalized, dendronised side chains are attached by click chemistry in the study of hydrocarbon structures with highly flexible spacers. Various degrees of sulfonation (DS) are used in the perspectivation...

  9. Moving beyond mass-based parameters for conductivity analysis of sulfonated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung [Los Alamos National Laboratory; Pivovar, Bryan [NREL

    2009-01-01

    Proton conductivity of polymer electrolytes is critical for fuel cells and has therefore been studied in significant detail. The conductivity of sulfonated polymers has been linked to material characteristics in order to elucidate trends. Mass based measurements based on water uptake and ion exchange capacity are two of the most common material characteristics used to make comparisons between polymer electrolytes, but have significant limitations when correlated to proton conductivity. These limitations arise in part because different polymers can have significantly different densities and conduction happens over length scales more appropriately represented by volume measurements rather than mass. Herein, we establish and review volume related parameters that can be used to compare proton conductivity of different polymer electrolytes. Morphological effects on proton conductivity are also considered. Finally, the impact of these phenomena on designing next generation sulfonated polymers for polymer electrolyte membrane fuel cells is discussed.

  10. Synthesis and Antifungal Activity of Novel Sulfone Derivatives Containing 1,3,4-Oxadiazole Moieties

    Directory of Open Access Journals (Sweden)

    Maoguo Tong

    2011-11-01

    Full Text Available A series of new sulfone compounds containing 1,3,4-oxadiazole moieties were synthesized. The structures of these compounds were confirmed by spectroscopic data (IR, 1H- and 13C-NMR and elemental analyses. Antifungal tests indicated that all the title compounds exhibited good antifungal activities against eight kinds of plant pathogenic fungi, and some showed superiority over the commercial fungicide hymexazol. Among them, compounds 5d, 5e, 5f, and 5i showed prominent activity against B. cinerea, with determined EC50 values of 5.21 μg/mL, 8.25 µg/mL, 8.03 µg/mL, and 21.00 µg/mL, respectively. The present work demonstrates that sulfone derivatives such as 5d containing a 1,3,4-oxadiazole moiety can be used as possible lead compounds for the development of potential agrochemicals.

  11. Direct esterification of olive-pomace oil using mesoporous silica supported sulfonic acids

    Directory of Open Access Journals (Sweden)

    F. Alrouh

    2017-02-01

    Full Text Available Mesoporous silica MCM-41 and SBA-15 containing propyl sulfonic acid groups were synthesized according to the literature and were characterized by X-ray diffraction, N2 adsorption and the H+ exchange capacities of the sulfonic acid groups were titrated. The esterification reaction of glycerol with olive-pomace oil has been carried out by using prepared functionalized mesoporous silica (MCM-41 and SBA-15 as catalysts. It has been monitored by GC two fatty acids (palmitic and oleic acids as reactants in olive-pomace oil and their related monoacylglycerols (Glycerol monopalmitate GMP and monooleate GMO as reaction product. The catalytic activities of the functionalized mesoporous silica were compared with commercial catalysts, these included homogeneous catalysts (p-toluenesulfonic acid and heterogeneous catalysts (Amberlyst-15. The total yield of monoacylglycerols (GMO + GMP was nearly 40%. Remarkably, we found that MCM-41-SO3H was recycled at least 3 times without any loss of activity.

  12. Cell Adhesion and Proliferation on Sulfonated and Non-Modified Chitosan Films.

    Science.gov (United States)

    Martínez-Campos, Enrique; Civantos, Ana; Redondo, Juan Alfonso; Guzmán, Rodrigo; Pérez-Perrino, Mónica; Gallardo, Alberto; Ramos, Viviana; Aranaz, Inmaculada

    2017-05-01

    Three types of chitosan-based films have been prepared and evaluated: a non-modified chitosan film bearing cationizable aliphatic amines and two films made of N-sulfopropyl chitosan derivatives bearing both aliphatic amines and negative sulfonate groups at different ratios. Cell adhesion and proliferation on chitosan films of C2C12 pre-myoblastic cells and B16 cells as tumoral model have been tested. A differential cell behavior has been observed on chitosan films due to their different surface modification. B16 cells have shown lower vinculin expression when cultured on sulfonated chitosan films. This study shows how the interaction among cells and material surface can be modulated by physicochemical characteristics of the biomaterial surface, altering tumoral cell adhesion and proliferation processes.

  13. Extended x-ray absorption fine structure: Studies of zinc-neutralized sulfonated polystyrene ionomers

    International Nuclear Information System (INIS)

    Ding, Y.S.; Yarusso, D.J.; Pan, H.K.D.; Cooper, S.L.

    1984-01-01

    Extended x-ray absorption fine structure (EXAFS) measurements were performed on a series of zinc-neutralized sulfonated polystyrene ionomers and the local structure around the zinc atom was determined. An interference effect in the EXAFS signal between sulfur and oxygen atoms was found to be significant in these materials. A model for the local structure in the zinc-neutralized sulfonated polystyrene ionomers is proposed which suggests a highly ordered tetrahedral coordination of oxygen around the zinc atoms at a distance of 1.97 +- 0.02 A. In addition there are four sulfur atoms and four oxygen atoms at a distance of 3.15 +- 0.05 A. No zinc-zinc coordination within 5 A was detected in this study

  14. A sulfonated poly (aryl ether ether ketone ketone) isomer: synthesis and DMFC performance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung [Los Alamos National Laboratory; Liu, Baijun [JILIN UNIV.; Hu, Wei [JILIN UNIV.; Jiang, Zhenhua [JILIN UNIV.; Robertson, Gilles [CANADA NRC; Guiver, Michael [CANADA NRC

    2009-01-01

    A sulfonated poly(aryl ether ether ketone ketone) (PEEKK) having a well-defined rigid homopolymer-like chemical structure was synthesized from a readily-prepared PEEKK post-sulfonation with concentrated sulfuric acid at room temperature within several hours. The polymer electrolyte membrane (PEM) cast from the resulting polymer exhibited an excellent combination of thermal resistance, oxidative and dimensional stability, low methanol fuel permeability and high proton conductivity. Furthermore, membrane electrode assemblies (MEAs) were successfully fabricated and good direct methanol fuel cell (DMFC) performance was observed. At 2 M MeOH feed, the current density at 0.5 V reached 165 mA/cm, which outperformed our reported analogues and eveluated Nafion membranes.

  15. Electrochemiluminescence sensor based on partial sulfonation of polystyrene with carbon nanotubes.

    Science.gov (United States)

    Li, Jing; Xu, Yuanhong; Wei, Hui; Huo, Ting; Wang, Erkang

    2007-07-15

    Herein, homogenously partial sulfonation of polystyrene (PSP) was performed. An effective electrochemiluminescence (ECL) sensor based on PSP with carbon nanotube (CNTs) composite film was developed. Cyclic voltammetry and electrochemical impendence spectroscopy were applied to characterize this composite film. The PSP was used as an immobilization matrix to entrap the ECL reagent Ru(bpy)3(2+) due to the electrostatic interactions between sulfonic acid groups and Ru(bpy)3(2+) cations. The introduction of CNTs into PSP acted not only as a conducting pathway to accelerate the electron transfer but also as a proper matrix to immobilize Ru(bpy)3(2+) on the electrode by hydrophobic interaction. Furthermore, the results indicated the ECL intensity produced at this composite film was over 3-fold compared with that of the pure PSP film due to the electrocatalytic activity of the CNTs. Such a sensor was verified by the sensitive determinations of 2-(dibutylamino)ethanol and tripropylamine.

  16. Sulfonated Styrene-(ethylene-co-butylene-styrene/Montmorillonite Clay Nanocomposites: Synthesis, Morphology, and Properties

    Directory of Open Access Journals (Sweden)

    Ganguly Anirban

    2007-01-01

    Full Text Available AbstractSulfonated styrene-(ethylene-butylene-styrene triblock copolymer (SSEBS was synthesized by reaction of acetyl sulfate with SEBS. SSESB-clay nanocomposites were then prepared from hydrophilic Na-montmorillonite (MT and organically (quaternary amine modified hydrophobic nanoclay (OMT at very low loading. SEBS did not show improvement in properties with MT-based nanocomposites. On sulfonation (3 and 6 weight% of SEBS, hydrophilic MT clay-based nanocomposites exhibited better mechanical, dynamic mechanical, and thermal properties, and also controlled water–methanol mixture uptake and permeation and AC resistance. Microstructure determined by X-ray diffraction, atomic force microscopy, and transmission electron microscopy due to better dispersion of MT nanoclay particles and interaction of MT with SSEBS matrix was responsible for this effect. The resulting nanocomposites have potential as proton transfer membranes for Fuel Cell applications.

  17. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Zhensheng; Bi, Cheng; Dai, Hua [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Li, Xianfeng [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China)

    2011-01-01

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test. (author)

  18. Stabilized sulfonated aromatic polymers by in situ solvothermal cross-linking

    Directory of Open Access Journals (Sweden)

    Maria Luisa eDi Vona

    2014-10-01

    Full Text Available The cross-link reaction via sulfone bridges of sulfonated polyetheretherketone (SPEEK by thermal treatment at 180 °C in presence of dimethylsulfoxide (DMSO is discussed. The modifications of properties subsequent to the cross-linking are presented. The mechanical strength as well as the hydrolytic stability increased with the thermal treatment time, i.e., with the degree of cross-linking. The proton conductivity was determined as function of temperature, IEC, degree of cross-linking and hydration number. The memory effect, which is the membrane ability to remember the water uptake reached at high temperature also at lower temperature, is exploited in order to achieve high values of conductivity. Membranes swelled at 110 °C can reach a conductivity of 0.14 S/cm at 80°C with a hydration number ( of 73.

  19. Quinolinium 8-hy-droxy-7-iodo-quinoline-5-sulfonate 0.8-hydrate.

    Science.gov (United States)

    Smith, Graham

    2012-12-01

    In the crystal structure of the title hydrated quinolinium salt of ferron (8-hy-droxy-7-iodo-quinoline-5-sulfonic acid), C9H7N(+)·C9H5INO4S(-)·0.8H2O, the quinolinium cation is fully disordered over two sites (occupancy factors fixed at 0.63 and 0.37) lying essentially within a common plane and with the ferron anions forming π-π-associated stacks down the b axis [minimum ring centroid separation = 3.462 (6) Å]. The cations and anions are linked into chains extending along c through hy-droxy O-H⋯O and quinolinium N-H⋯O hydrogen bonds to sulfonate O-atom acceptors which are also involved in water O-H⋯O hydrogen-bonding inter-actions along b, giving a two-dimensional network.

  20. Quinolinium 8-hydroxy-7-iodoquinoline-5-sulfonate 0.8-hydrate

    Directory of Open Access Journals (Sweden)

    Graham Smith

    2012-12-01

    Full Text Available In the crystal structure of the title hydrated quinolinium salt of ferron (8-hydroxy-7-iodoquinoline-5-sulfonic acid, C9H7N+·C9H5INO4S−·0.8H2O, the quinolinium cation is fully disordered over two sites (occupancy factors fixed at 0.63 and 0.37 lying essentially within a common plane and with the ferron anions forming π–π-associated stacks down the b axis [minimum ring centroid separation = 3.462 (6 Å]. The cations and anions are linked into chains extending along c through hydroxy O—H...O and quinolinium N—H...O hydrogen bonds to sulfonate O-atom acceptors which are also involved in water O—H...O hydrogen-bonding interactions along b, giving a two-dimensional network.

  1. Effects of 17β-oestradiol and norethisterone acetate on sulfonation and sialylation of gonadotrophins in post-menopausal women

    Science.gov (United States)

    Naessén, Tord; Eriksson, Karin

    2010-01-01

    Background The number of terminal sialic acid and sulfonated N-acetylgalactosamine (SO3-GalNAc) on gonadotrophins in serum varies during the menstrual cycle and changes at menopause, suggesting that gonadal steroids modify their oligosaccharide synthesis. Our objective was to determine the effects of 17β-oestradiol (E2) and a progestogen, norethisterone acetate (NETA), on the sulfonation and sialylation of gonadotrophins in post-menopausal women. Methods Serum samples were obtained from eight post-menopausal women treated with 20 mg E2 implants every 6 months, from four women who in addition were treated daily with 5 mg NETA orally for a 2-week period, and from four women who got this NETA treatment during a 4-week period. Sera from 11 non-treated post-menopausal women served as a reference group. The gonadotrophin serum concentrations, the number of SO3-GalNAc and sialic acid residues per serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) molecule, and the distributions of molecules with 0-1-2-3-4 sulfonated residues were measured. Results The E2-treated post-menopausal women had considerably less (P sulfonation of LH (P sulfonation of LH and FSH. The primary effect of the NETA therapy was an increase in the sulfonation of LH and FSH concomitantly with secondary and consequentially decreases in sialylation of LH. PMID:20141368

  2. Sulfonation Process and Desalination Effect of Polystyrene/PVDF Semi-Interpenetrating Polymer Network Cation Exchange Membrane

    Directory of Open Access Journals (Sweden)

    Yin-lin Lei

    2014-07-01

    Full Text Available With the classical sulfonation method of polystyrene-based strongly acidic cation exchange resins, polystyrene/polyvinylidene fluoride (PVDF alloy particles were sulfonated to obtain a cation exchange resin, which was then directly thermoformed to prepare a semi-interpenetrating polymer network (semi-IPN cation exchange membrane. The effects of the swelling agent, sulfonation time and temperature and the relative contents of polystyrene and divinylbenzene (DVB in the alloy particles on the feasibility of the membrane formation are discussed. The results indicate that a favorable sulfonation degree above 80% and a suitable ion exchange capacity of 1.5–2.4 mmol/g can be gained, with concentrated sulfuric acid as the sulfonation agent and 1,2-dichloroethane as the swelling agent. The running electrical resistance and desalination effect of the prepared cation exchange membrane were measured in a pilot-scale electrodialyser and not only obviously exceeded a commercial heterogeneous cation exchange membrane, but was also very close to a commercial homogenous membrane. In this way, the authors have combined the classical sulfonation method of polystyrene-based cation exchange resins with the traditional thermoforming manufacturing process of heterogeneous cation exchange membranes, to successfully develop a novel, low-price, but relatively high-performance polystyrene/PVDF cation exchange membrane with the semi-IPN structure.

  3. Effects of 17beta-oestradiol and norethisterone acetate on sulfonation and sialylation of gonadotrophins in post-menopausal women.

    Science.gov (United States)

    Wide, Leif; Naessén, Tord; Eriksson, Karin

    2010-05-01

    The number of terminal sialic acid and sulfonated N-acetylgalactosamine (SO(3)-GalNAc) on gonadotrophins in serum varies during the menstrual cycle and changes at menopause, suggesting that gonadal steroids modify their oligosaccharide synthesis. Our objective was to determine the effects of 17beta-oestradiol (E(2)) and a progestogen, norethisterone acetate (NETA), on the sulfonation and sialylation of gonadotrophins in post-menopausal women. Serum samples were obtained from eight post-menopausal women treated with 20 mg E(2) implants every 6 months, from four women who in addition were treated daily with 5 mg NETA orally for a 2-week period, and from four women who got this NETA treatment during a 4-week period. Sera from 11 non-treated post-menopausal women served as a reference group. The gonadotrophin serum concentrations, the number of SO(3)-GalNAc and sialic acid residues per serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) molecule, and the distributions of molecules with 0-1-2-3-4 sulfonated residues were measured. The E(2)-treated post-menopausal women had considerably less (P sulfonation of LH (P sulfonation of LH and FSH. The primary effect of the NETA therapy was an increase in the sulfonation of LH and FSH concomitantly with secondary and consequentially decreases in sialylation of LH.

  4. Degradation of Imidazolium- and Quaternary Ammonium-Functionalized Poly(fluorenyl ether ketone sulfone) Anion Exchange Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, DY; Hickner, MA

    2012-11-01

    Imidazolium and quaternary ammonium-functionalized poly(fluorenyl ether ketone sulfone)s were synthesized successfully with the same degree of cationic functionalization and identical polymer backbones for a comparative study of anion exchange membranes (AEMs) for solid-state alkaline membrane fuel cells (AMFCs). Both anion exchange membranes were synthesized using a new methyl-containing monomer that avoided the use of toxic chloromethylation reagents. The polymer chemical structures were confirmed by H-1 NMR and FTIR. The derived AEMs were fully characterized by water uptake, anion conductivity, stability under aqueous basic conditions, and thermal stability. Interestingly, both the cationic groups and the polymer backbone were found to be degraded in 1 M NaOH solution at 60 degrees C over 48 h as measured by changes of ion exchange capacity and intrinsic viscosity. Imidazolium-functionalized poly(fluorenyl ether ketone sulfone)s had similar aqueous alkaline stability to quaternary ammonium-functionalized materials at 60 degrees C but much lower stability at 80 degrees C. This work demonstrates that quaternary ammonium and imidazolium cationic groups are not stable on poly(arylene ether sulfone) backbones under relatively mild conditions. Additionally, the poly(arylene ether sulfone) backbone, which is one of the most common polymers used in ion exchange membrane applications, is not stable in the types of molecular configurations analyzed.

  5. Syntheses, structures, thermal stabilities and luminescence of two new lead sulfonates with phosphonate, carboxylate and pyridine

    International Nuclear Information System (INIS)

    Fu, Ruibiao; Hu, Shengmin; Wu, Xintao

    2014-01-01

    Hydrothermal reactions of Pb 2+ ion with disodium 4,4'-bis(2-sulfonatostyryl)biphenyl (Na 2 L1), 4-pyridyl-CH 2 N(CH 2 COOH)(CH 2 PO 3 H 2 ) (H 3 L2) and 4,4'-bipyridine (4,4'-bipy) afforded two new lead sulfonates, namely, [Pb 4 (L1) 2 (HL2) 2 (H 2 O)

  6. Solvent and irradiation doses effects on the ion exchange capacity of sulfonated styrene grafted PVDF

    International Nuclear Information System (INIS)

    Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B.

    2011-01-01

    Polymers exhibiting ion exchange capacity are studied for many years due to their application in several fields, such as membranes for proton exchange fuel cells, filtration membranes, heavy ions recovery and artificial muscles and sensors. Radiation induced grafting followed by sulfonation is a well-known way to obtain ion exchange polymers. Fluorinated polymers are frequently used as polymeric matrix for grafting due to their excellent physicochemical properties. Radiation induced grafting of styrene into poly (vinylidene fluoride) (PVDF) by simultaneous method in 1:1 styrene/toluene or styrene/N,N-dimethylformamide solutions was studied. Irradiations were performed under nitrogen atmosphere, room temperature and at doses of 5, 10 and 20 kGy with dose rate of 5 kGy.h -1 from a 60 Co gamma source. After washing, grafted materials were sulfonated in 10% chlorosulfonic acid/1,2-dichloroethane solutions for 4 h at room temperature. Characterization shows that increasing irradiation dose corresponds to increases in the grafting yield (GY %) gravimetrically calculated and these different solvents shows different grafting behaviors. Toluene allows no more than 3 % of grafting while DMF allows up to 55 % of grafting in the same condition. Grafting in toluene solution occurs on the surface and in DMF solution it occurs in the bulk, as confirmed by SEM. Both irradiation doses and solvent used have direct effects in the ion exchange capacities (calculated after titrations). FT-IR spectra exhibit new peaks after grafting and after sulfonation, attributed to grafted monomer and sulfonic groups attached to the styrene. DSC shows differences in thermal behavior of the polymer before and after each step. (author)

  7. Polyalkoxy sulfonate, CO/sub 2/ and brine drive process for oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Wellington, S. L.; Bright, D. B.; Lutz, E. F.; Reisberg, J.

    1985-03-05

    Oil is displaced within a subterranean reservoir by injecting a combination of substantially liquefied CO/sub 2/, brine and surfactant material into the reservoir, with the surfactant material being a polyalkoxy aliphatic sulfonate surfactant material which has specified dispersing and partitioning properties in contact with the brine and the fluids in the reservoir at the reservoir temperature and a pressure sufficient to substantially liquefy the CO/sub 2/ within the reservoir.

  8. Solvent and irradiation doses effects on the ion exchange capacity of sulfonated styrene grafted PVDF

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Henrique P.; Parra, Duclerc F.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Polymers exhibiting ion exchange capacity are studied for many years due to their application in several fields, such as membranes for proton exchange fuel cells, filtration membranes, heavy ions recovery and artificial muscles and sensors. Radiation induced grafting followed by sulfonation is a well-known way to obtain ion exchange polymers. Fluorinated polymers are frequently used as polymeric matrix for grafting due to their excellent physicochemical properties. Radiation induced grafting of styrene into poly (vinylidene fluoride) (PVDF) by simultaneous method in 1:1 styrene/toluene or styrene/N,N-dimethylformamide solutions was studied. Irradiations were performed under nitrogen atmosphere, room temperature and at doses of 5, 10 and 20 kGy with dose rate of 5 kGy.h{sup -1} from a {sup 60}Co gamma source. After washing, grafted materials were sulfonated in 10% chlorosulfonic acid/1,2-dichloroethane solutions for 4 h at room temperature. Characterization shows that increasing irradiation dose corresponds to increases in the grafting yield (GY %) gravimetrically calculated and these different solvents shows different grafting behaviors. Toluene allows no more than 3 % of grafting while DMF allows up to 55 % of grafting in the same condition. Grafting in toluene solution occurs on the surface and in DMF solution it occurs in the bulk, as confirmed by SEM. Both irradiation doses and solvent used have direct effects in the ion exchange capacities (calculated after titrations). FT-IR spectra exhibit new peaks after grafting and after sulfonation, attributed to grafted monomer and sulfonic groups attached to the styrene. DSC shows differences in thermal behavior of the polymer before and after each step. (author)

  9. Evaluation of Sulfonate-Based Collectors with Different Hydrophobic Tails for Flotation of Fluorite

    Directory of Open Access Journals (Sweden)

    Renji Zheng

    2018-02-01

    Full Text Available This investigation aims to demonstrate the effects of hydrophobic tails on the affinity and relevant flotation response of sulfonate-based collectors for fluorite. For this purpose, a series of alkyl sulfonates with different hydrophobic tails, namely sodium decanesulfonate (C10, sodium dodecylsulfate (C12, sodium hexadecanesulfonate (C16, and sodium dodecylbenzenesulfonate (C12B were applied. The flotation tests showed that C12 and C12B had a better collecting performance than C10 and C16 at pH < 10, and the flotation recovery of fluorite was higher when adopting C12B as a collector compared with C12 with a strong base. The adsorption behaviors of collectors on the fluorite surface were studied through zeta potential, Fourier transform infrared (FTIR, and X-ray photoelectron spectroscopy (XPS analyses. It was found that the affinity of alkyl sulfonates for fluorite was enhanced with the increase of the alkyl chain length from C10 to C16. The existence of phenyl in the hydrophobic tail of sulfonates could improve its activity for fluorite by reducing its surface tension. The abnormal phenomenon C16 with a high affinity for fluorite had a low collecting performance for fluorite mainly due to its overlong alkyl chain, resulting in low solubility in pulp, which restrained its interaction with fluorite. We concluded that C12B was the most applicable collector for fluorite among these reagents due to its high activity, high solubility, and low cost, which was further substantiated by calculating their molecular frontier orbital energy.

  10. Facile Synthesis of Effcient and Selective Ruthenium Olefin Metathesis Catalysts with Sulfonate and Phosphate Ligands

    OpenAIRE

    Teo, Peili; Grubbs, Robert H.

    2010-01-01

    A series of novel, air-stable ruthenium NHC catalysts with sulfonate and phosphate anions have been prepared easily in one pot at high yields using commercially available precursors. The catalysts were found to be effective for ring-opening metathesis polymerization, ring-closing metathesis, and cross-metathesis. The catalysts showed higher cis-selectivity in olefin cross-metathesis reactions as compared to earlier known ruthenium-based olefin metathesis catalysts, with allylbenzene and cis-1...

  11. The design and synthesis of novel spirocyclic heterocyclic sulfone ROMK inhibitors as diuretics.

    Science.gov (United States)

    Chobanian, Harry R; Guo, Yan; Pio, Barbara; Tang, Haifeng; Teumelsan, Nardos; Clements, Matthew; Frie, Jessica; Ferguson, Ronald; Guo, Zach; Thomas-Fowlkes, Brande S; Felix, John P; Liu, Jessica; Kohler, Martin; Priest, Birgit; Hampton, Caryn; Pai, Lee-Yuh; Corona, Aaron; Metzger, Joseph; Tong, Vincent; Joshi, Elizabeth M; Xu, Ling; Owens, Karen; Maloney, Kevin; Sullivan, Kathleen; Pasternak, Alexander

    2017-02-15

    A spirocyclic class of ROMK inhibitors was developed containing a structurally diverse heterocyclic sulfone moiety and spirocyclic core starting from lead 1. These compounds not only displayed exquisite ROMK potency but significantly improved selectivity over hERG. The lead compounds were found to have favorable pharmacokinetic properties and displayed robust diuretic, natriuretic and blood pressure lowering effects in spontaneously hypertensive rats. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Electrooxidative Tandem Cyclization of Activated Alkynes with Sulfinic Acids To Access Sulfonated Indenones

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Jiangwei [The; Center; Shi, Wenyan [The; Zhang, Fan [The; Liu, Dong [The; Tang, Shan [The; Wang, Huamin [The; Lin, Xiao-Min [Center; Lei, Aiwen [The

    2017-05-25

    An,electrooxidative direct arylsulfonlylation of yones sulfintc acids via a radical tandem cyclization strategy has been developed for the construction of sulfonated ilicIenones:under oxidant, free conditions. This method provides a simple and efficient approach to prepare various sulfonylindenones in good to,excellent:Tyidds,, demonstrating the tremendous prospect of utilizing electrocatalysis in oxidative coupling, Notably, this reaction could Be easily scaled up with good, efficiency.

  13. Morphological studies and ionic transport properties of partially sulfonated diblock copolymers

    Czech Academy of Sciences Publication Activity Database

    Gromadzki, D.; Černoch, Peter; Janata, Miroslav; Kůdela, Vlastimil; Nallet, F.; Diat, O.; Štěpánek, Petr

    2006-01-01

    Roč. 42, č. 10 (2006), s. 2486-2496 ISSN 0014-3057 R&D Projects: GA ČR GESON/03/E001 Grant - others:Marie Curie Research and Training Network(XE) HPMT-CT-2001-00396 Institutional research plan: CEZ:AV0Z40500505 Keywords : sulfonated polystyrene-block-hydrogenated polyisoprene * ionomer * morphology Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.113, year: 2006

  14. Efficient conversion of levulinic acid into alkyl levulinates catalyzed by sulfonic mesostructured silicas

    OpenAIRE

    Melero, J.A.; Morales, G.; Iglesias, J.; Paniagua, M.; Hernández, B.; Penedo, S.

    2013-01-01

    Línea Investigación: Línea 8. Producción de biocombustibles Sulfonic mesoporous silicas have demonstrated an outstanding catalytic performance in the esterification of levulinic acid with different alcohols to produce alkyl levulinates, a family of chemicals considered to be excellent oxygenated fuel extenders for gasoline, diesel and biodiesel. Catalyst screening indicated that propylsulfonic acid-modified SBA-15 material was the most active one, among tested materials, due to a combinati...

  15. Design and synthesis of aryl ether and sulfone hydroxamic acids as potent histone deacetylase (HDAC) inhibitors.

    Science.gov (United States)

    Pabba, Chittari; Gregg, Brian T; Kitchen, Douglas B; Chen, Zhen Jia; Judkins, Angela

    2011-01-01

    A series of novel hydroxamic acid based histone deacetylases (HDAC) inhibitors with aryl ether and aryl sulfone residues at the terminus of a substituted, unsaturated 5-carbon spacer moiety have been synthesized for the first time and evaluated. Compounds with meta- and para-substitution on the aryl ring of ether hydroxamic acids 19c, 20c, 19e, 19f and 19g are potent HDAC inhibitors with activities at low nanomolar levels. Copyright © 2010 Elsevier Ltd. All rights reserved.

  16. Electrophilic aromatic sulfonation with SO3: concerted or classic S(E)Ar mechanism?

    Science.gov (United States)

    Koleva, Gergana; Galabov, Boris; Kong, Jing; Schaefer, Henry F; Schleyer, Paul von R

    2011-11-30

    The electrophilic sulfonation of several arenes with SO(3) was examined by electronic structure computations at the M06-2X/6-311+G(2d,2p) and SCS-MP2/6-311+G(2d,2p) levels of theory. In contrast to the usual interpretations, the results provide clear evidence that in nonpolar media and in the absence of catalysts the mechanism of aromatic sulfonation with a single SO(3) is concerted and does not involve the conventionally depicted 1:1 σ complex (Wheland) intermediate. Moreover, the computed activation energy for the 1:1 process is unrealistically high; barriers for alternative 2:1 mechanisms involving attack by two SO(3) molecules are 12-20 kcal/mol lower! A direct 2:1 sulfonation mechanism, involving a single essential transition state, but no Wheland type intermediate, is preferred generally at MP2 as well as at M06-2X in isolation (gas phase) or in noncomplexing solvents (such as CCl(4) or CFCl(3)). However, in polar, higher dielectric SO(3)-complexing media, M06-2X favors an S(E)Ar mechanism for the 2:1 reaction involving a Wheland-type arene-(SO(3))(2) dimer intermediate. The reaction is slower in complexing solvents, since the association energy, e.g., with nitromethane, must be overcome. But, in accord with the experimental kinetics (second-order in SO(3)), attack by two sulfur trioxide molecules is still favored energetically over reaction with a single SO(3) in CH(3)NO(2). The theoretical results also reproduce the experimental reactivity and regioselectivity trends for benzene, toluene, and naphthalene sulfonation accurately.

  17. Direct sulfonation of methane to methanesulfonic acid with SO2 using Ca salts as promoters.

    Science.gov (United States)

    Mukhopadhyay, Sudip; Bell, Alexis T

    2003-04-16

    Direct liquid-phase sulfonation of methane to methanesulfonic acid (MSA) with SO2 has been achieved in triflic acid using K2S2O8 as the oxidant and a small amount of a Ca salt as the promoter. The effects of reaction conditions on the conversion of SO2 to MSA were examined. Included were the influence of solvent acidity, reaction duration, reaction temperature, amount of K2S2O8, and composition and amount of promoters.

  18. Distinct sulfonation activities in resveratrol-sensitive and resveratrol-insensitive human glioblastoma cells.

    Science.gov (United States)

    Sun, Zheng; Li, Hong; Shu, Xiao-Hong; Shi, Hui; Chen, Xiao-Yan; Kong, Qing-You; Wu, Mo-Li; Liu, Jia

    2012-07-01

    Glioblastoma multiforme (GBM) cells show different responses to resveratrol, for unknown reasons. Our data from human medulloblastoma cells and primary cultures of rat brain cells revealed an inverse correlation of sulfonation activity with resveratrol sensitivities, providing a clue to the underlying mechanisms of the variable sensitivities of GBM cells to resveratrol. In this study, we found that U251 cells were sensitive and LN229 cells were insensitive to resveratrol. Thus, these two cell lines were taken as comparable models for elucidating the influence of sulfonation activities on resveratrol sensitivity. HPLC showed identical resveratrol metabolic patterns in both cell lines. LC/MS and high-resolution mass MS analyses further demonstrated that resveratrol monosulfate generated by sulfotransferases (SULTs) was the major metabolite of human GBM cells. The levels of brain-associated SULT (SULT1A1, SULT1C2, and SULT4A1) expression in U251 cells were lower than those in LN229 cells, suggesting the inverse relationship of SULT-mediated sulfonation activity with high intracellular resveratrol bioavailability and resveratrol sensitivity of human GBM cells. Furthermore, immunohistochemical staining revealed reductions in expression of the three brain-associated SULTs in 72.8%, 47.5% and 66.3% of astrocytomas, respectively. Therefore, the levels of brain-associated SULTs and sulfonation activity mediated by them could be important parameters for evaluating the potential response of human GBM cells to resveratrol, and may have value in the personalized treatment of GBMs with resveratrol. © 2012 The Authors Journal compilation © 2012 FEBS.

  19. The acid-base character of interactions between xenon and selected carboxylic and sulfonic acids

    Science.gov (United States)

    Gąszowski, Dawid; Ilczyszyn, Marek

    2017-05-01

    Interactions of Xe atoms with RCO2H and RSO3H (R = CH3 and CF3) acids in different solvents are examined by analysis of 129Xe chemical shifts extrapolated to zero solvent concentration. Obtained results are very sensitive to the Xe contacts with the methyl and trifluoromethyl groups as well as with the carboxylic and sulfonic groups of different acidity. The acid-base character of these acid-Xe interactions is considered.

  20. Sulfonation of maternal steroids is a conserved metabolic pathway in vertebrates.

    Science.gov (United States)

    Paitz, Ryan T; Bowden, Rachel M

    2013-12-01

    All vertebrate embryos develop in the presence of maternally derived steroids, and maternal steroids have been hypothesized to link phenotype of the offspring to maternal physiology. In placental vertebrates, it is known that maternally derived steroids are metabolized during development via the sulfonation pathway. We used eggs from the red-eared slider turtle (Trachemys scripta) to determine whether the same metabolic pathway is used to metabolize maternally derived steroids in an oviparous vertebrate. To examine the relationship between estradiol and estrogen sulfates during development, levels of maternally derived estradiol were compared with levels of estradiol sulfate, estrone sulfate, and estriol sulfate at oviposition and after 20 days of embryonic development. Estrone sulfate was the only detectable estrogen sulfate. At oviposition, levels of both estradiol and estrone sulfate varied seasonally with clutches from later in the nesting season having significantly higher concentrations of both steroids. Levels of estrone sulfate increased during development, demonstrating that the sulfonation of maternally derived steroids occurs in oviparous vertebrates as well as in placental vertebrates. We also found that exogenous estrone sulfate increases the production of female hatchlings, thereby demonstrating the ability of this metabolite to influence embryonic development. To examine the role of sulfonation in the metabolism of maternal progesterone and testosterone, we characterized the metabolic fate of both steroids by applying tritiated forms of each steroid at oviposition and characterizing metabolites after 20 days of incubation. Similar to what was demonstrated for estradiol, both progesterone and testosterone are converted to sulfonated metabolites during embryonic development. These data suggest that steroid sulfates, both those that are maternally derived and those resulting from the metabolism of maternal steroids, are a key component of the mechanism

  1. In silico approach to investigating the adsorption mechanisms of short chain perfluorinated sulfonic acids and perfluorooctane sulfonic acid on hydrated hematite surface.

    Science.gov (United States)

    Feng, Hongru; Lin, Yuan; Sun, Yuzhen; Cao, Huiming; Fu, Jianjie; Gao, Ke; Zhang, Aiqian

    2017-05-01

    Short chain perfluorinated sulfonic acids (PFSAs) that were introduced as alternatives for perfluorooctane sulfonic acid (PFOS) have been widely produced and used. However, few studies have investigated the environmental process of short chain PFSAs, and the related adsorption mechanisms still need to be uncovered. The water-oxide interface is one of the major environmental interfaces that plays an important role in affecting the adsorption behaviour and transport potential of the environmental pollutant. In this study, we performed molecular dynamics simulations and quantum chemistry calculations to investigate the adsorption mechanisms of five PFSAs and their adsorption on hydrated hematite surface as well. Different to the vertical configuration reported for PFOS on titanium oxide, all PFSAs share the same adsorption configuration as the long carbon chains parallel to the surface. The formation of hydrogen bonds between F and inter-surface H helps to stabilize the unique configuration. As a result, the sorption capacity increases with increasing C-F chain length. Moreover, both calculated adsorption energy and partial density of states (PDOS) analysis demonstrate a PFSAs adsorption mechanism in between physical and chemical adsorption because the hydrogen bonds formed by the overlap of F (p) orbital and H (s) orbital are weak intermolecular interactions while the physical adsorption are mainly ascribed to the electrostatic interactions. This massive calculation provides a new insight into the pollutant adsorption behaviour, and in particular, may help to evaluate the environmental influence of pollutants. Copyright © 2017. Published by Elsevier Ltd.

  2. Influence of aromatic sulfonation on the geometry of [2.2]paracyclophane: crystal structures of one sulfonate, one disulfonic anhydride and five disulfonimides.

    Science.gov (United States)

    De Ridder, D J; Goubitz, K; Fontijn, M; Capková, P; Dova, E; Schenk, H

    2001-12-01

    The crystal structures of potassium [2.2]paracyclophane-4-sulfonate (1), [2.2]paracyclophane-4,15-disulfonic anhydride (2), [2.2]paracyclophane-4,15-disulfonimide (3), N-n-propyl-[2.2]paracyclophane-4,15-disulfonimide (4), N-isopropyl-[2.2]paracyclophane-4,15-disulfonimide (5), N-cyclopropyl-[2.2]paracyclophane-4,15-disulfonimide (6) and N-phenyl-[2.2]paracyclophane-4,15-disulfonimide (7) were established by single-crystal X-ray diffraction. The structural changes caused by sulfonation are discussed with respect to the parent [2.2]paracyclophane (tricyclo[8.2.2.2(4,7)]hexadeca-4,6,10,12,13,15-hexaene). The main features are a change in the non-bonding distances between the para-phenylene rings and a rotation of these rings with respect to the molecular symmetry plane. The rings are rotated away from each other in the case of monosulfonation (1), but are rotated in the opposite way in the case of the disulfonic anhydride (2) or the disulfonimide compounds (3)-(7). The results are also discussed in terms of the parameters proposed by Keehn [(1983), Organic Chemistry, A Series of Monographs 45, edited by P. H. Keehn & S. M. Rosenfeld, Vol. 1, pp. 69-238. New York: Academic Press] showing that (bonded and non-bonded) angles involving the para-phenylene rings are mainly affected.

  3. en las relaciones entrenadas

    Directory of Open Access Journals (Sweden)

    Camilo Hurtado P.

    2005-01-01

    Full Text Available El presente estudio exploró los efectos en la adquisición y transferencia de discriminaciones condicionales debidos a las diferentes combinaciones de relaciones entrenadas (identidad-diferencia-semejanza en una tarea de igualación a la muestra de segundo orden. De manera complementaria, fueron además dispuestas en la tarea las características que en estudios relacionados habían sido reportadas como facilitadoras de ejecuciones efectivas, a saber: el uso de instrucciones inespecíficas, arreglos de estímulo de tres formas y dos colores y el entrenamiento concurrente de las relaciones. Ocho sujetos fueron distribuidos en cuatro grupos que variaron en la combinación de relaciones a entrenar. Los resultados mostraron que gran parte de los sujetos cumplieron con el criterio de efectividad en entrenamiento y en transferencia extramodal y extrarrelacional, siendo la relación de identidad la relación en la cual se presentaron ejecuciones perfectas, al margen de si ésta había sido entrenada o no. Se discuten los resultados en términos de velocidad de ajuste a las relaciones y de las configuraciones de la tarea que facilitaron mejores desempeños. Se proponen, además, posibles investigaciones que superen las limitaciones metodológicas encontradas en este estudio y que exploren posibles interacciones de las variables manipuladas con otras variables de interés.

  4. Polystyrene sulfonate-porphyrin assemblies: influence of polyelectrolyte and porphyrin structure.

    Science.gov (United States)

    Ruthard, Christian; Maskos, Michael; Kolb, Ute; Gröhn, Franziska

    2011-05-19

    In this study, electrostatic self-assembly of different polystyrene sulfonates and a set of tetravalent cationic porphyrins is investigated. It is shown that association of linear polystyrene sulfonates of different molar masses yields finite size nanoscale assemblies that are stable in aqueous solution. Aggregates are compared to the ones of cylindrical brushes, revealing that both form assemblies in the 100 nm range with the charge ratio (molar ratio of porphyrin charges to polyelectrolyte charges) being determining, while the morphology of the resulting network-like assemblies is different for both polyelectrolyte architectures. For the smallest 8k polystyrene sulfonate, in addition, stoichiometric conditions differ. The influence of the molecular porphyrin structure was investigated by comparing meso-tetrakis(4-(trimethyl-ammonium)phenyl)porphyrin (TAPP) with its Cu(II) and Zn(II) loaded analogues and meso-tetrakis(4-N-methylpyridinium)porphyrin (TMPyP), revealing differences in stacking tendency and geometry. Additionally, the TMPyP accumulates more in the inside of the brush than the other porphyrins, likely due to the different position of its charged groups. The supramolecular nanostructures formed were characterized by UV-vis spectroscopy, light scattering, atomic force microscopy, cryo transmission electron microscopy, and small-angle neutron scattering. Results may build a valuable basis for the use of polyelectrolyte-porphyrin assemblies in medicine, catalysis, or energy conversion. © 2011 American Chemical Society

  5. Study of Synthesis Polyethylene glycol oleate Sulfonated as an Anionic Surfactant for Enhanced Oil Recovery (EOR)

    Science.gov (United States)

    Sampora, Yulianti; Juwono, Ariadne L.; Haryono, Agus; Irawan, Yan

    2017-11-01

    Mechanical Enhanced Oil Recovery (EOR) through chemical injection is using an anionic surfactant to improve the recovery of oil residues, particularly in a reservoir area that has certain characteristics. This case led the authors to conduct research on the synthesis of an anionic surfactant based on oleic acid and polyethylene glycol 400 that could be applied as a chemical injection. In this work, we investigate the sulfonation of Polyethylene glycol oleate (PDO) in a sulfuric acid agent. PDO in this experiment was derived from Indonesian palm oil. Variation of mole reactant and reaction time have been studied. The surfactant has been characterized by measuring the interfacial tension, acid value, ester value, saponification value, iodine value, Fourier Transform Infrared (FTIR), and particle size analyzer. There is a new peak at 1170-1178 cm-1 indicating that S=O bond has formed. PDO sulfonate exhibits good surface activity due to interfacial tension of 0,003 mN/m. Thus, polyethylene glycol oleate sulfonate was successfully synthesized and it could be useful as a novel an anionic surfactant.

  6. Efficient and selective adsorption of multi-metal ions using sulfonated cellulose as adsorbent.

    Science.gov (United States)

    Dong, Cuihua; Zhang, Fulong; Pang, Zhiqiang; Yang, Guihua

    2016-10-20

    Contamination of heavy metal in wastewater has caused great concerns on human life and health. Developing an efficient material to eliminate the heavy metal ions has been a popular topic in recent years. In this work, sulfonated cellulose (SC) was explored as efficient adsorbent for metal ions in solution. Thermo gravimetric analyzer (TGA), X-ray diffraction (XRD) and Fourier-transform infrared spectrometer (FTIR) first analyzed the characterizations of SC. Subsequently, effects of solution pH, adsorbent loading, temperature and initial metal ion concentration on adsorption performance were investigated. The results showed that sulfonated modification of cellulose could decrease the crystallinity and thermostability of cellulose. Due to its excellent performance of adsorption to metal ions, SC could reach adsorption equilibrium status within as short as 2min. In multi-component solution, SC can orderly removes Fe(3+), Pb(2+) and Cu(2+) with excellent selectivity and high efficiency. In addition, SC is a kind of green and renewable adsorbent because it can be easily regenerated by treatment with acid or chelating liquors. The mechanism study shows that the sulfonic group play a major role in the adsorption process. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. QENS investigation of proton confined motions in hydrated perfluorinated sulfonic membranes and self-assembled surfactants

    Directory of Open Access Journals (Sweden)

    Berrod Quentin

    2015-01-01

    Full Text Available We report on QuasiElastic Neutron Scattering (QENS investigations of the dynamics of protons and water molecules confined in nanostructured perfluorinated sulfonic acid (PFSA materials, namely a commercial Aquivion membrane and the perfluorooctane sulfonic acid (PFOS surfactant. The former is used as electrolyte in low-temperature fuel cells, while the latter forms mesomorphous self-assembled phases in water. The dynamics was investigated as a function of the hydration level, in a wide time range by combining time-of-flight and backscattering incoherent QENS experiments. Analysis of the quasielastic broadening revealed for both systems the existence of localized translational diffusive motions, fast rotational motions and slow hopping of protons in the vicinity of the sulfonic charges. The characteristic times and diffusion coefficients have been found to exhibit a very similar behaviour in both membrane and surfactant structures. Our study provides a comprehensive picture of the proton motion mechanisms and the dynamics of confined water in model and real PFSA nanostructures.

  8. A cell-based screen reveals that the albendazole metabolite, albendazole sulfone, targets Wolbachia.

    Directory of Open Access Journals (Sweden)

    Laura R Serbus

    2012-09-01

    Full Text Available Wolbachia endosymbionts carried by filarial nematodes give rise to the neglected diseases African river blindness and lymphatic filariasis afflicting millions worldwide. Here we identify new Wolbachia-disrupting compounds by conducting high-throughput cell-based chemical screens using a Wolbachia-infected, fluorescently labeled Drosophila cell line. This screen yielded several Wolbachia-disrupting compounds including three that resembled Albendazole, a widely used anthelmintic drug that targets nematode microtubules. Follow-up studies demonstrate that a common Albendazole metabolite, Albendazole sulfone, reduces intracellular Wolbachia titer both in Drosophila melanogaster and Brugia malayi, the nematode responsible for lymphatic filariasis. Significantly, Albendazole sulfone does not disrupt Drosophila microtubule organization, suggesting that this compound reduces titer through direct targeting of Wolbachia. Accordingly, both DNA staining and FtsZ immunofluorescence demonstrates that Albendazole sulfone treatment induces Wolbachia elongation, a phenotype indicative of binary fission defects. This suggests that the efficacy of Albendazole in treating filarial nematode-based diseases is attributable to dual targeting of nematode microtubules and their Wolbachia endosymbionts.

  9. Esterification of oleic acid with ethanol catalyzed by sulfonated cation exchange resin: Experimental and kinetic studies

    International Nuclear Information System (INIS)

    Jiang, Yuwang; Lu, Jie; Sun, Kaian; Ma, Lingling; Ding, Jincheng

    2013-01-01

    Graphical abstract: - Highlights: • Esterification of oleic acid with ethanol was investigated in the presence of sulfonated cation exchange resin. • We studied kinetic model of the esterification of oleic acid with ethanol according to experimental data. • The proposed kinetic model can well predict oleic acid conversion. - Abstract: This paper investigated the effects of ethanol to oleic acid molar ratio, reaction temperature, catalyst loading, water content and catalyst recycling on sulfonated cation exchange resin in a stirred batch reactor under atmospheric pressure. When the esterification was carried out with an ethanol to oleic acid (42.4 g) molar ratio of 9:1, reflux of ethanol at 82 °C, 20 g of catalyst and 8 h of reaction time, the oleic acid conversion rate reached approximately 93%. A pseudo-homogeneous kinetic model for describing the esterification of oleic acid with ethanol by the sulfonated cation exchange resin was developed on the basis of laboratorial results. The kinetic model can well predict the oleic acid conversion

  10. Synthesis, structural, solubility and anticancer activity studies of salts using nucleobases and sulfonic acids coformer

    Science.gov (United States)

    Singh, Neetu; Singh, Udai P.; Nikhil, Kumar; Roy, Partha; Singh, Hariji

    2017-10-01

    The reactions of natural and unnatural nucleobases (cytosine (Cyt), adenine (Ade), 5-aminouracil (AU) and caffeine (Caff)) with sulfonic acids coformer (1,5-naphthalenedisulfonic acid, NDSA; 5-sulfosalicylic acid, SSA) resulted in the formation of salts viz. [NDSA.Cyt] (1), [NDSA.Ade] (2), [NDSA.AU] (3), [NDSA.Caff] (4), [SSA.Cyt] (5), [SSA.Ade] (6), [SSA.AU] (7), and [SSA.Caff] (8). The structural analysis revealed that salts 1, 4, 6 and 7 have intermolecular interactions between adjacent nucleobases which form two different homodimer shown in R22 (8) motif and assembled via complementary Nsbnd H⋯O and Nsbnd H⋯N interactions. However, in all other salts an intermediate supramolecular synthon pattern was observed between nucleobases and sulfonic acids. The lattice energy was also calculated by DFT to investigate whether salts were thermodynamically more stable than its coformer. The same was further confirmed by differential scanning calorimetry-thermogravimetric (DSC-TG) analysis. The anticancer activity study of individual nucleobases and their NDSA salts were also performed on human breast (MCF-7) and lung (A 549) cancer cell. The salts formation of nucleobases with sulfonic acids improved their solubility, thereby demonstrating up to 8-fold increase in solubility of nucleobases.

  11. Nanocasting Design and Spatially Selective Sulfonation of Polystyrene-Based Polymer Networks as Solid Acid Catalysts.

    Science.gov (United States)

    Richter, Felix H; Sahraoui, Laila; Schüth, Ferdi

    2016-09-12

    Nanocasting is a general and widely applied method in the generation of porous materials during which a sacrificial solid template is used as a mold on the nanoscale. Ideally, the resulting structure is the inverse of the template. However, replication is not always as direct as anticipated, so the influences of the degree of pore filling and of potential restructuring processes after removal of the template need to be considered. These apparent limitations give rise to opportunities in the synthesis of poly(styrene-co-divinylbenzene) (PSD) polymer networks of widely varying porosities (BET surface area=63-562 m(2)  g(-1) ; Vtot =0.18-1.05 cm(3)  g(-1) ) by applying a single synthesis methodology. In addition, spatially selective sulfonation on the nanoscale seems possible. Together, nanocasting and sulfonation enable rational catalyst design. The highly porous nanocast and predominantly surface-sulfonated PSD networks approach the activity of the corresponding molecular catalyst, para-toluenesulfonic acid, and exceed those of commercial ion-exchange polymers in the depolymerization of macromolecular inulin. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Properties of Polymer Electrolyte Membranes Prepared by Blending of Sulfonated Polystyrene-Lignosulfonate

    Directory of Open Access Journals (Sweden)

    Siang Tandi Gonggo

    2012-11-01

    Full Text Available Electrolyte polymer membrane widely used in PEMFC and DMFC is a perfluorosulfonated membrane such as Nafion. This membrane material exhibits good chemical stability and proton conductivity, but it is very expensive and difficult to recycle. It has high cross-over methanol in DMFC that causes the decrease efficiency and performance of fuel cell, so that the electrolyte polymer membrane with low cross-over methanol has been needed to substitute Nafion membrane. One of the materials used as a polymer electrolyte membrane is polyblends of a sulfonated polystyrene-lignosulfonate (SPS-LS. These polyblends have been prepared by casting polymer solution and characterized as a polyelectrolyte membrane for DMFC. SPS was prepared by sulfonation of polystyrene with acetyl sulfate used as a sulfonating agent. The membranes of SPS-LS were characterized by analysis of functional groups, mechanical properties, and methanol permeability. The maximum mechanical properties of the SPS-LS membrane were observed in LS ratio of 7.5%. However, the methanol permeability of membrane increases as the increase of LS ratio in SPS-LS membranes. The properties of membranes, especially the mechanical property and methanol permeability close to that of Nafion® 117 membrane, so the SPS-LS membrane is highly potential used as the electrolyte membrane for direct methanol fuel cell.

  13. The Effects of Sulfonated Poly(ether ether ketone) Ion Exchange Preparation Conditions on Membrane Properties

    Science.gov (United States)

    Yee, Rebecca S. L.; Zhang, Kaisong; Ladewig, Bradley P.

    2013-01-01

    A low cost cation exchange membrane to be used in a specific bioelectrochemical system has been developed using poly(ether ether ketone) (PEEK). This material is presented as an alternative to current commercial ion exchange membranes that have been primarily designed for fuel cell applications. To increase the hydrophilicity and ion transport of the PEEK material, charged groups are introduced through sulfonation. The effect of sulfonation and casting conditions on membrane performance has been systematically determined by producing a series of membranes synthesized over an array of reaction and casting conditions. Optimal reaction and casting conditions for producing SPEEK ion exchange membranes with appropriate performance characteristics have been established by this uniquely systematic experimental series. Membrane materials were characterized by ion exchange capacity, water uptake, swelling, potential difference and NMR analysis. Testing this extensive membranes series established that the most appropriate sulfonation conditions were 60 °C for 6 h. For mechanical stability and ease of handling, SPEEK membranes cast from solvent casting concentrations of 15%–25% with a resulting thickness of 30–50 µm were also found to be most suitable from the series of tested casting conditions. Drying conditions did not have any apparent impact on the measured parameters in this study. The conductivity of SPEEK membranes was found to be in the range of 10−3 S cm−1, which is suitable for use as a low cost membrane in the intended bioelectrochemical systems. PMID:24956945

  14. Simple surface sulfonation retards plasticiser migration and impacts upon blood/material contact activation processes.

    Science.gov (United States)

    Gourlay, Terence; Shedden, Laurie; Horne, David; Stefanou, Demetrios M

    2010-01-01

    The use of Di-2-ethylhexyl phthalate (DEHP) plasticised polyvinyl chloride (DEHPPPVC) in medical devices persists despite evidence suggesting that DEHP migration can be harmful. Researchers have shown that a simple surface sulfonation process can retard the migration of DEHP, which may reduce the associated inflammatory response. The present study is designed to investigate the effects of surface sulfonation on DEHP migration and blood contact activation using in vitro and rodent models. The study was carried out in two phases: phase 1, in which the migration rate of DEHP from DEHPPPVC and sulfonated DEHP plasticised PVC (SDEHPPPVC) was measured; phase 2 of the study, in which the materials were incorporated into a rat recirculation biomaterial test model and blood samples taken to assess CD11b expression on neutrophils, IL-6 and Factor XIIa. The initial DEHP concentration washed from the surface after storage was 37.19 +/- 1.17 mg/l in the PPVC group and 5.89 +/- 0.81 mg/l in the SPPVC group (psulfonation process significantly retards the migration of DEHP and is associated with the moderation of contact activation processes.

  15. Highly Efficient Inverted Perovskite Solar Cells With Sulfonated Lignin Doped PEDOT as Hole Extract Layer.

    Science.gov (United States)

    Wu, Ying; Wang, Junyi; Qiu, Xueqing; Yang, Renqiang; Lou, Hongming; Bao, Xichang; Li, Yuan

    2016-05-18

    Sulfonated-acetone-formaldehyde (SAF) was grafted with alkali lignin (AL) to prepare grafted sulfonated-acetone-formaldehyde lignin (GSL). Considering the rich phenolic hydroxyl groups in GSL, we detected a hole mobility of 2.27 × 10(-6) cm(2) V(-1) s(-1) with GSL as a hole transport material by space-charge-limited current model. Compared with nonconjugated poly(styrene sulfonic acid), GSL was applied as p-type semiconductive dopant for PEDOT to prepare water-dispersed GSL. GSL shows enhanced conductivity compared with that of PSS. Simultaneously, the enhanced open-circuit voltage, short-circuit current density, and fill factor are achieved using GSL as a hole extract layer (HEL) in sandwich-structure inverted perovskite solar cells. The power conversion efficiency is increased to 14.94% compared with 12.6% of PSS-based devices. Our results show that amorphous GSL is a good candidate as dopant of PEDOT, and we provide a novel prospective for the design of HEL based on lignin, a renewable biomass and phenol derivatives.

  16. The Effects of Sulfonated Poly(ether ether ketone Ion Exchange Preparation Conditions on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rebecca S. L. Yee

    2013-08-01

    Full Text Available A low cost cation exchange membrane to be used in a specific bioelectrochemical system has been developed using poly(ether ether ketone (PEEK. This material is presented as an alternative to current commercial ion exchange membranes that have been primarily designed for fuel cell applications. To increase the hydrophilicity and ion transport of the PEEK material, charged groups are introduced through sulfonation. The effect of sulfonation and casting conditions on membrane performance has been systematically determined by producing a series of membranes synthesized over an array of reaction and casting conditions. Optimal reaction and casting conditions for producing SPEEK ion exchange membranes with appropriate performance characteristics have been established by this uniquely systematic experimental series. Membrane materials were characterized by ion exchange capacity, water uptake, swelling, potential difference and NMR analysis. Testing this extensive membranes series established that the most appropriate sulfonation conditions were 60 °C for 6 h. For mechanical stability and ease of handling, SPEEK membranes cast from solvent casting concentrations of 15%–25% with a resulting thickness of 30–50 µm were also found to be most suitable from the series of tested casting conditions. Drying conditions did not have any apparent impact on the measured parameters in this study. The conductivity of SPEEK membranes was found to be in the range of 10−3 S cm−1, which is suitable for use as a low cost membrane in the intended bioelectrochemical systems.

  17. Las neurosis actuales y las psicosis ordinarias

    OpenAIRE

    Aguirre, Javier

    2013-01-01

    El trabajo tiene por finalidad poner en tensión las categorías de psicosis ordinaria y neurosis actuales. En primer lugar, se procede a examinar ambas categorías para luego establecer sus puntos de coincidencia y disidencia. Se concluye que la categoría de neurosis actual propuesta por Freud, es una posible expresión de lo que en la actualidad se llama psicosis ordinaria.

  18. Historia de las series

    OpenAIRE

    Cascajosa Virino, Concepción

    2017-01-01

    Reseña: Historia de las series de Toni de la Torre: la gran impostura Durante mucho tiempo los profesores de cine en España se han quejado (amargamente y en privado) de la recurrencia en la bibliografía de los trabajos de sus estudiantes de los libros de un autor conocido por la escasa calidad de sus textos, cuyos vistosos títulos garantizan que acaben en las estanterías de las bibliotecas universitarias. Es muy propio de la cultura española hacer duras aseveraciones en foros irrelevantes y, ...

  19. Las Leyes de Newton

    OpenAIRE

    González S., Fabio

    2015-01-01

    La labor de Newton en el campo de la física, una de las piedras angulares en que se fundamenta esta ciencia, se caracteriza por el hecho de que a partir de unos enunciados básicos explica los diversos fenómenos que estudia la mecánica. Entre las grandes contribuciones de Newton se pueden citar: el descubrimiento de la ley de la gravitación universal, el enunciado de las leyes del movimiento, el teorema del binomio, la formulación básica del cálculo diferencial e integral, así-como algunos tra...

  20. Sulfonation of poly(N-vinylcarbazole) studied by combined time-of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy

    Science.gov (United States)

    Weng; Wong; Ho; Wang; Zeng; Yang

    2000-10-15

    A series of sulfonated poly(N-vinylcarbazole) (PVK) samples have been systematically studied by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and X-ray photoelectron spectroscopy (XPS). Negative TOF-SIMS results provided unambiguous evidence that sulfonate groups are chemically attached to the carbazole moiety of PVK. The positive SIMS spectrum of PVK was, however, little affected by the sulfonation reaction. The degree of sulfonation was quantitatively determined by XPS. Therefore, the combination of TOF-SIMS and XPS is useful to follow the sulfonation reaction, both qualitatively and quantitatively. The SIMS intensities of some characteristic fragments are linearly related to the degree of sulfonation, suggesting that quantitative analysis is possible from TOF-SIMS data.

  1. Las fronteras de Israel

    Directory of Open Access Journals (Sweden)

    Arie M. Kacowicz

    2008-01-01

    Full Text Available En el presente artículo haré una breve reseña histórica de la evolución de las fronteras (inconclusas del Estado de Israel entre 1948 y 2007. En primer lugar, presento un modelo teórico sobre el desarrollo y la evolución de las fronteras, tanto por la vía pacífi ca como por la bélica. En segundo lugar, hago una reseña histórica de la evolución de las fronteras de Israel desde su independencia hasta el presente. El artículo también hace referencia detallada a los problemas pendientes con respecto a las negociaciones entre Israel y los palestinos.

  2. Las Serpientes en Colombia

    Directory of Open Access Journals (Sweden)

    Daniel H.

    1949-12-01

    Full Text Available El estudio de las serpientes en Colombia no deja de tener su particular interés; existe una inmensa variedad de especies que se escalonan desde los valles ardientes hasta alturas relativamente considerables; en estos últimos puntos disminuye notablemente la variedad de formas y de modo especial las especies provistas de veneno. Hacer una distinción entre las especies venenosas y las inofensivas, resulta un tanto difícil; en algunos textos se dan unas cuántas reglas, pero la mayor parte de ellas sólo tienen aplicación con especies exóticas ya que la mayor parte de esas distinciones se han tomado de obras que hacen referencia a la fauna europea.

  3. Las vacas imitadores expertos

    OpenAIRE

    Chevalier, Pedro

    2009-01-01

    La mayoría de las especies del género Hypoplectrus presentan un comportamiento conocido como mimetismo agresivo. Este fenómeno consiste en la imitación de los patrones de coloración, por parte de las vacas, de peces que no son depredadores de crustáceos y pequeños peces. Al imitar el color de peces inofensivos pueden acercarse a sus presas sin que estas huyan.

  4. Triclosan is a potent inhibitor of estradiol and estrone sulfonation in sheep placenta.

    Science.gov (United States)

    James, Margaret O; Li, Wenjun; Summerlot, David P; Rowland-Faux, Laura; Wood, Charles E

    2010-11-01

    The personal care product Triclosan, 5-chloro-2(2,4-dichlorophenoxy)-phenol, is widely used in consumer products as an antibacterial agent and is increasingly found in the environment as a contaminant of sewage sludge and wastewater. This compound has been identified in plasma and urine of people in the United States, Sweden and Australia. Triclosan is known to inhibit sulfonation of phenolic xenobiotics and is structurally related to inhibitors of estrogen sulfotransferase, such as polychlorobiphenylols. In pregnancy, the placenta is an important source of estrogen, which is needed for normal fetal development and successful parturition, and estrogen sulfotransferase is thought to play an important role in regulation of estrogen availability. In this study, we examined the effect of Triclosan on sheep placental cytosolic sulfotransferase activity with 17-beta-estradiol and estrone as substrates. For comparison, we studied the effects of 4-hydroxy-3,3',4',5-tetrachlorobiphenyl and 2'-hydroxytriclocarban on estradiol sulfonation. The apparent K(m) for placental cytosolic sulfotransferase activity with estradiol as substrate was 0.27 ± 0.06 nM (mean ± S.D., n = 3 individuals) and with estrone as substrate was 1.86 ± 0.22 nM. Partial substrate inhibition was observed with estradiol at concentrations higher than 10-20 nM, as is typical of estrogen sulfotransferases (SULT1E1) in other species. Studies of the effect of Triclosan on estrogen sulfotransferase activity were conducted with several concentrations (0.1-6 nM) of estradiol and with 2 nM estrone. Triclosan was a very potent inhibitor of both estradiol and estrone sulfonation. For estradiol the inhibition was shown to be mixed competitive/uncompetitive, with K(ic) of 0.09 ± 0.01 nM and K(iu) of 5.2 ± 2.9 nM. The IC(50) for inhibition of estrone sulfonation was 0.60 ± 0.06 nM. At an environmentally relevant concentration of 1 µM, Triclosan was not a substrate for glucuronidation in sheep placental microsomes

  5. Serum half-life of pituitary gonadotropins is decreased by sulfonation and increased by sialylation in women.

    Science.gov (United States)

    Wide, Leif; Eriksson, Karin; Sluss, Patrick M; Hall, Janet E

    2009-03-01

    The gonadotropins are secreted from the human pituitary as spectra of isoforms with different degrees of sulfonation and sialylation of the oligosaccharides, modifications suspected to determine their half-lives in the circulation. Our objectives were to determine the isoform composition of the serum gonadotropins during GnRH receptor blockade, and to estimate the half-lives in circulation of isoforms with 0-1-2-3 sulfonated N-acetylgalactosamine (SO(3)-GalNAc) residues. Serum samples were collected in seven healthy women before and up to 20 h after administration of the NAL-GLU GnRH antagonist. The number of sialic acid and SO(3)-GalNAc residues per LH and FSH molecule and the distribution of molecules with 0-1-2-3 sulfonated residues were measured. The half-lives were estimated by monoexponential decay. More sialylated and less sulfonated gonadotropin isoforms remain longer in circulation during GnRH receptor blockade. LH isoforms with two and three sulfonated residues per molecule had shorter half-lives compared with those with zero and one (109 and 80 vs. 196 and 188 min; P sulfonated residues had shorter half-lives than those with zero (485 and 358 vs. 988 min; P sulfonated and increase in sialylated residues. The rapid disappearance of LH isoforms with two and three SO(3)-GalNAc residues suggests their removal by hepatic SO(3)-GalNAc-receptors similar to those in rodents. Episodical secretion of spectra of isoforms with different half-lives is expected to lead to continuous changes in gonadotropin isoform compositions in blood.

  6. S-sulfonation of transthyretin is an important trigger step in the formation of transthyretin-related amyloid fibril.

    Science.gov (United States)

    Nakanishi, Toyofumi; Yoshioka, Masanori; Moriuchi, Kazuyoshi; Yamamoto, Daisuke; Tsuji, Motomu; Takubo, Takayuki

    2010-07-01

    Senile systemic amyloidosis and familial amyloid polyneuropathy are caused by oxidative deposition of conformationally altered transthyretin (TTR). We identified oxidative modification of the 10th cysteine of TTR through S-sulfonation in vitro. Based on mass spectrometric analysis, we determined the spectrophotometric, western blotting, and fluorescent microscopic properties of TTR incubated with and without cysteine-S-sulfonate in acidic (pH 4) and alkaline (pH 8) conditions at 37 degrees. The absorption of the aggregated TTR molecules increased more with incubation time and the concentration of cysteine-S-sulfonate at pH 4 than at pH 8. The Congo red binding to the S-sulfonated TTR at pH 4 was saturated with an apparent Bmax of 2.01 mol per mole of the S-sulfonated TTR and apparent KD of 7.75x10(-6) M. On the other hand, the Bmax of cysteinyl TTR was 1.38, and its KD was 3.52x10(-6) M while the Bmax of reduced TTR was 0.86, and its KD was 2.86x10(-6) M. Moreover, we detected positive amyloid fibril staining using Thioflavin T and Congo red with the S-sulfonated TTR but not with untreated or reduced TTR by microscopic fluorescent analysis. After modification of TTR in vitro, oligomers resisted reduction and denaturation was irreversibly induced, and which contributed differences in the Western blotting patterns obtained with four anti-TTR antibodies. In conclusion, this study showed that the formation of S-sulfonation of TTR through oxidative modifications of the thiol residue on the 10th cysteine of TTR is an important trigger step in the formation of transthyretin-related amyloid fibril. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  7. Isotope-coded N-terminal sulfonation of peptides allows quantitative proteomic analysis with increased de novo peptide sequencing capability.

    Science.gov (United States)

    Lee, Yong Ho; Han, Hoon; Chang, Seok-Bok; Lee, Sang-Won

    2004-01-01

    Recently various methods for the N-terminal sulfonation of peptides have been developed for the mass spectrometric analyses of proteomic samples to facilitate de novo sequencing of the peptides produced. This paper describes the isotope-coded N-terminal sulfonation (ICenS) of peptides; this procedure allows both de novo peptide sequencing and quantitative proteomics to be studied simultaneously. As N-terminal sulfonation reagents, 13C-labeled 4-sulfophenyl[13C6]isothiocyanate (13C-SPITC) and unlabeled 4-sulfophenyl isothiocyanate (12C-SPITC) were synthesized. The experimental and reference peptide mixtures were derivatized independently using 13C-SPITC and 12C-SPITC and then combined to generate an isotopically labeled peptide mixture in which each isotopic pair differs in mass by 6 Da. Capillary reverse-phase liquid chromatography/tandem mass spectrometry experiments on the resulting peptide mixtures revealed several immediate advantages of ICenS in addition to the de novo sequencing capability of N-terminal sulfonation, namely, differentiation between N-terminal sulfonated peptides and unmodified peptides in mass spectra, differentiation between N- and C-terminal fragments in tandem mass spectra of multiply protonated peptides by comparing fragmentations of the isotopic pairs, and relative peptide quantification between proteome samples. We demonstrate that the combination of N-terminal sulfonation and isotope coding in the mass spectrometric analysis of proteomic samples is a viable method that overcomes many problems associated with current N-terminal sulfonation methods. Copyright 2004 John Wiley & Sons, Ltd.

  8. Parmentier, las patatas y las ollas americanas

    Directory of Open Access Journals (Sweden)

    Clément, Jean-Pierre

    1995-12-01

    Full Text Available The discovery of new agricultural and alimentary possibilities was one of the most important motives of the numerous scientific expeditions sent to America during the XVIIIth Century. Some French scientists (naturalists, medical, botanical, etc., undertook, during the second half of the Enlightment Century, an active campaign in favor of the potato consumption. The most well-known was the pharmacist Parmentier that settled his propaganda upon political arguments (the potato gives of eating all the population, economical (it is an easy plant of cultivating and of good efficiency, and scientific (excellent nutritious qualities.

    El descubrimiento de nuevas posibilidades agroalimentarias fue uno de los más importantes motivos de las numerosas expediciones científicas enviadas a América durante el siglo XVIII. Algunos científicos galos (naturalistas, médicos, botánicos, etc., emprendieron, en la segunda mitad del siglo de las Luces, una activa campaña en favor del consumo de la patata por los hombres. El más conocido fue el farmacéutico Parmentier, que asentó su propaganda sobre argumentos políticos (la patata da de comer a toda la población, económicos (es una planta fácil de cultivar y de buen rendimiento, y científicos (excelentes cualidades nutritivas.

  9. Las colonias fronterizas

    Directory of Open Access Journals (Sweden)

    Jeffery Brannon

    1989-09-01

    Full Text Available Este artículo examina el rápido crecimiento de las comunidades irregulares que son habitadas por población de escasos recursos, predominantemente hispana, localizadas en áreas desincorporadas de lado norteamericano de la frontera México-Estados Unidos durante la década de los ochenta. Alrededor de 175 o 200 mil personas actualmente viven en estas llamadas "colonias", mismas que frecuentemente están aisladas de las áreas urbanas cercanas y sin disponer de acceso adecuado a los servicios públicos básicos tales como agua, drenaje y transporte público. La inmigración de mexicanos a los Estados Unidos y la escasez de viviendas a precios módicos están identificados como los factores principales en la creación de estas comunidades. El Paso, Texas es utilizado como caso para el estudio de la dinámica social, política y económica del crecimiento de las "colonias". En este artículo se llega a la conclusión de que serán necesarias inciativas innovadoras, principalmente locales, para minimizar las consecuencias potenciales negativas del desarrollo irregular de anillos de pobreza alrededor de las áreas urbanas ubicadas en el lado norteamericano de la frontera.

  10. Thiophene-degrading Escherichia coli mutants possess sulfone oxidase activity and show altered resistance to sulfur-containing antibiotics

    Energy Technology Data Exchange (ETDEWEB)

    Juhl, M.J.; Clark, D.P. (Southern Illinois Univ., Carbondale (USA))

    1990-10-01

    The authors have previously isolated mutants of Escherichia coli which show increased oxidation of heterocyclic furan and thiophene substrates. They have now found that strains carrying the thdA mutation express a novel enzyme activity which oxidizes a variety of substrates containing a sulfone (e.g., ethyl sulfone) were oxidized. The thdA mutants were more resistant than wild-type strains to aromatic sulfone antibiotics such as dapsone. In contrast they showed increased susceptibility to thiolutin, a cyclic antibiotic containing sulfur at the sulfide level of oxidation. Several new thdA mutant alleles were isolated by selecting for increased oxidation of various aliphatic sulfur compounds. These new thdA mutants showed similar sulfone oxidase activity and the same map location (at 10.7 min) as the original thdA1 mutation. The constitutive fadR mutation was required for the phenotypic expression of thdA-mediated oxidation of sulfur compounds. However, the thdA-directed expression of sulfone oxidase activity was not fadR dependent. The thdC and thdD mutations probably protect against the toxicity of thiophene derivatives rather than conferring improved metabolic capability.

  11. Improving the Conductivity of Sulfonated Polyimides as Proton Exchange Membranes by Doping of a Protic Ionic Liquid

    Directory of Open Access Journals (Sweden)

    Bor-Kuan Chen

    2014-10-01

    Full Text Available Proton exchange membranes (PEMs are a key component of a proton exchange membrane fuel cell. Sulfonated polyimides (SPIs were doped by protic ionic liquid (PIL to prepare composite PEMs with substantially improved conductivity. SPIs were synthesized from diamine, 2,2-bis[4-(4-amino-phenoxyphenyl]propane (BAPP, sulfonated diamine, 4,4'-diamino diphenyl ether-2,2'-disulfonic acid (ODADS and aromatic anhydride. BAPP improved the mechanical and thermal properties of SPIs, while ODADS enhanced conductivity. A PIL, 1-vinylimidazolium trifluoromethane-sulfonate ([VIm][OTf], was utilized. [VIm][OTf] offered better conductivity, which can be attributed to its vinyl chemical structure attached to an imidazolium ring that contributed to ionomer-PIL interactions. We prepared sulfonated polyimide/ionic liquid (SPI/IL composite PEMs using 50 wt% [VIm][OTf] with a conductivity of 7.17 mS/cm at 100 °C, and in an anhydrous condition, 3,3',4,4'-diphenyl sulfone tetracarboxylic dianhydride (DSDA was used in the synthesis of SPIs, leading to several hundred-times improvement in conductivity compared to pristine SPIs.

  12. THE USE OF CHLOROSULFONIC ACID ON SULFONATION OF cPTFE FILM GRAFTED STYRENE FOR PROTON EXCHANGE MEMBRANE

    Directory of Open Access Journals (Sweden)

    Yohan Yohan

    2010-06-01

    Full Text Available Sulfonation of g-ray iradiated and styrene-grafted crosslinked polytetrafluoro ethylene film (cPTFE-g-S film have been done. The aim of the research was to make hydrophyl membrane as proton exchange membrane fuel cell. Sulfonation was prepared by using chlorosulfonic acid in chloroethane under various conditions. The impact of the percentage of grafting, the concentration of chlorosulfonic acid, the reaction time,and the reaction temperature on the properties of sulfonated film were examined. The results show that sulfonation of surface-grafted films was incomplete at room temperature. Increasing concentration of chlorosulfonic acid and reaction temperature accelerate the reaction but they also favor side reactions. These lead to the decrease of the ion-exchange capacity, water uptake, and proton conductivity but the increase of the resistance to oxidation in a perhydrol solution. The resulted cPTFE-g-SS membraneis stabile in a H2O2 30% solution for 20 h.   Keywords: Chorosulfonic acid, sulfonation, PTFE film, proton excange membrane.

  13. Synthesis and Antibacterial Evaluation of New Sulfone Derivatives Containing 2-Aroxymethyl-1,3,4-Oxadiazole/Thiadiazole Moiety

    Directory of Open Access Journals (Sweden)

    Shihu Su

    2016-12-01

    Full Text Available Sulfones are one of the most important classes of agricultural fungicides. To discover new lead compounds with high antibacterial activity, a series of new sulfone derivatives were designed and synthesized by introducing the aroxymethyl moiety into the scaffold of 1,3,4-oxadiazole/thiadiazole sulfones. Antibacterial activities against three phytopathogens (Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, Xanthomonas axonopodis pv. citri. were assayed in vitro. As compared to the control of commercial fungicides and some reported sulfone fungicides, seven compounds 5I-1–5I-7 exerted remarkably higher activities with EC50 values ranging from 0.45–1.86 μg/mL against X. oryzae and 1.97–20.15 μg/mL against R. solanacearum. Exhilaratingly, 5I-1, 5I-2 and 5I-4 displayed significant in vivo activity against X. oryzae with protective effect of 90.4%, 77.7%, and 81.1% at 200 μg/mL, respectively, much higher than that exhibited by Bismerthiazol (25.6% and Thiadiazole-copper (32.0%. And the differential phytotoxicity of active derivatives was preliminarily checked. The results demonstrated that derivative of 2-aroxymethyl-1,3,4-oxadiazole/thiadiazole sulfone can serve as potential alternative bactericides for the management of plant bacterial diseases.

  14. Arylsulfatase B Mediates the Sulfonation-Transport Interplay in Human Embryonic Kidney 293 Cells Overexpressing Sulfotransferase 1A3.

    Science.gov (United States)

    Zhao, Mengjing; Wang, Shuai; Li, Feng; Dong, Dong; Wu, Baojian

    2016-09-01

    Elucidating the intricate relationships between metabolic and transport pathways contributes to improved predictions of in vivo drug disposition and drug-drug interactions. Here we reported that inhibited excretion of conjugative metabolites [i.e., hesperetin 3'-O-sulfate (H3'S) and hesperetin 7-O-sulfate (H7S)] by MK-571 led to reduced metabolism of hesperetin (a maximal 78% reduction) in human embryonic kidney 293 cells overexpressing sulfotransferase 1A3 (named SULT293 cells). The strong dependence of cellular sulfonation on the efflux transport of generated sulfated metabolites revealed an interplay of sulfonation metabolism with efflux transport (or sulfonation-transport interplay). Polymerase chain reaction (PCR) and Western blot analyses demonstrated that SULT293 cells expressed multiple sulfatases such as arylsulfatase A (ARSA), ARSB, and ARSC. Of these three desulfonation enzymes, only ARSB showed significant activities toward hesperetin sulfates. The intrinsic clearance values for the hydrolysis of H3'S and H7S were estimated at 0.6 and 0.5 μl/h/mg, respectively. Furthermore, knockdown of ARSB attenuated the regulatory effect of efflux transporter on cellular sulfonation, whereas overexpression of ABSB enhanced the transporter effect. Taken together, the results indicated that ARSB mediated the sulfonation-transport interplay in SULT293 cells. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  15. Heparin antiproliferative activity on bovine pulmonary artery smooth muscle cells requires both N-acetylation and N-sulfonation.

    Science.gov (United States)

    Longas, María O; Garg, Hari G; Trinkle-Pereira, Jennifer M; Hales, Charles A

    2003-01-31

    The antiproliferative activity of Heparin (HP) on bovine pulmonary artery smooth muscle cells (BPASMC) in vitro requires both N-acetylation and N-sulfonation. This was demonstrated by quantifying the relative N-acetylation of three commercial heparins of known antiproliferative activities, using their Fourier-transform infrared (FTIR) band areas at 1381-1378 and 1320-1317 cm(-1), which combined resulted in 1.0, 1.0 and 1.3 cm2 for Choay, Elkins-Sinn and Upjohn HP, respectively. These results show that Upjohn HP, which is at least 44% more antiproliferative than the other two, is 30% more N-acetylated. Upjohn HP was also N-desulfonated chemically, and its antiproliferative activity was determined. Its total sulfonate (--SO 3 -) content (O- and N-sulfonate) was quantified using the FTIR band area at 1260-1200 cm(-1) for the S=O stretching; a drop in sulfonate content from 21.87% (w/w) before N-desulfonation to 16.51% (w/w) after N-desulfonation, resulted in a 67% decrease in its inhibitory potency. In addition to the requirement that approximately 24% of the sulfonate content be bonded to N, the data show a direct correlation between the extent of Upjohn HP N-acetylation and its antiproliferative activity on BPASMC.

  16. [Sulfonation modification-assisted enrichment and identification of histidine-containing peptides by strong cation exchange chromatography and mass spectrometry].

    Science.gov (United States)

    Cao, Dong; Zhou, Chunxi; Zhang, Yangjun; Han, Chunguang; Deng, Yulin; Qian, Xiaohong

    2009-03-01

    By the sulfonation at the N-terminal of peptides, the charge state of histidine-containing peptides is different from that of other peptides in pH sulfonated histidine-containing peptides from tryptic digest of proteins by strong cation exchange (SCX) chromatography and matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF MS/MS). Using the standard proteins containing histidines as the model, the methodology was evaluated. The results show that sulfonated histidine-containing peptides were efficiently enriched by SCX, and the N-terminal sulfonation of the peptides simplifies the interpretation of the acquired mass spectra and facilitates the sequencing of histidine-containing peptides by producing consecutive and predominant ions in positive mode MS2 spectra, which is thought to be the result of the charge neutralization of b ions by the N-terminal sulfonic acid group. The discrimination of b ions and y ions can greatly enhance the confidence in peptide and subsequent protein identification. It is feasible to isolate and enrich the histidine-containing peptides by using this method which has the potential applications in proteomics.

  17. Novel sulfonated poly(arylene ether ketone) copolymers bearing carboxylic or benzimidazole pendant groups for proton exchange membranes

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Haidan; Zhao, Chengji; Ma, Wenjia; Fu, Tiezhu; Na, Hui [Alan G. MacDiarmid Institute, College of Chemistry, Jilin University, Changchun 130012 (China); Cui, Zhiming; Xing, Wei [Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2009-09-05

    A novel strategy in which the benzimidazole group and sulfonic group are simultaneously attached to an aromatic polymer has been reported in this paper. For this purpose, sulfonated poly(arylene ether ketone) copolymers containing carboxylic acid groups (SPAEK-x-COOH, x refers to the molar percentage of sulfonated repeating units) are prepared by the aromatic nucleophilic polycondensation of sodium 5,5'-carbonyl-bis(2-fluobenzene-sulfonate) (SDFBP), 4,4'-difluorobenzophenone (DFBP) and phenolphthalin (PPL). Then the carboxylic acid groups attached to the SPAEK-x-COOH are transformed to benzimidazole units through condensation reactions (referred to as SPAEK-x-BI). Fourier transform infrared spectroscopy and {sup 1}H NMR measurements are used to characterize and confirm the structures of these copolymers. SPAEK-x-COOH membranes exhibit superior mechanical properties with maximum elongations at break up to 133%, meanwhile SPAEK-x-BI also shows good thermal and mechanical stability. The proton conductivity, swelling ratio and methanol permeability of the polymers with benzimidazole are lower than those with carboxylic groups, which indicated that there is an acid-base complex between benzimidazole and sulfonic acid groups. A balance of proton conductivity, methanol permeability, thermal and mechanical stabilities can be designed by incorporation of functional groups to meet the requirements for the applications in direct methanol fuel cells. (author)

  18. Las finanzas personales

    Directory of Open Access Journals (Sweden)

    Luis Olmedo Figueroa Delgado

    2013-08-01

    Full Text Available El éxito en la administración de las finanzas personales puede provenir de diversos estamentos, sin embargo, se estructura un elemento esencial que permite tomar decisiones consientes y más coherentes en el quehacer diario, el cual es el “presupuesto”, es por ello que en este articulo artículo se tomara esta herramienta financiera como elemento pivote que cumplirá dos fines principales: El resultado lógico y eficiente de una serie de actividades cotidianas que permite tomar decisiones en beneficio personal, en donde podremos entender el vocablo personal si se quiere familiar y el punto de partida para elaborar alguna estrategia que genere un rediseño los gastos o las inversiones actualmente realizadas y de esta manera encontrar un bienestar adicional en la administración de las finanzas personales.

  19. Tratamiento de las ictericias

    Directory of Open Access Journals (Sweden)

    Roberto de Zubiría

    1955-05-01

    Full Text Available En el tratamiento de los síndromes ictéricos no existe sistematización de criterios y en más de una ocasión se cometen serios errores terapéuticos. Tal sucede frecuentemente con las hepatitis a virus, por ejemplo las que tratadas con un régimen alimenticio inadecuado, constituído casi siempre por dietas de hambre, se va a complicar más la situación. Otras veces se utilizan sistemáticamente los antibióticos de amplio espectro, los cuales son inútiles e inclusive desaconsejados por la posibilidad de producir fibrosis hepática. Hemos querido hacer un resumen analizando someramente el pro y el contra de las principales medidas terapéuticas.

  20. Internet de las cosas

    OpenAIRE

    Salazar Soler, Jorge; Silvestre Bergés, Santiago

    2016-01-01

    Este es un curso de introducción a la IoT (Internet de las cosas). En los capítulos primeros capítulos se introducen los conceptos básicos sobre la IoT. Seguidamente se presentan nociones básicas sobre el protocolo de internet IPv6 que es el más utilizado en el entorno de la IoT y se describen las principales aplicaciones, el estado actual del mercado y las tecnologías que permiten la existencia de la IoT. Finalmente se analizan los retos de futuro que se consideran más importa...

  1. [Effect of sulfonation of polyethersulfone sheets on the adsorption of beta2-microglobulin].

    Science.gov (United States)

    Cheng, Liping; Sun, Shudong; Yue, Yilun; Huang, Jia; Mao, Huayi; Liang, Bo

    2005-06-01

    This study was performed to evaluate the adsorption of beta2-microglobulin(beta2 M) by blood dialysis membrane materials which are polyethersulfone (PES), sulfonated polyethersulfones, (PES-SO3Na-I and PES-SO3Na-I ) in vitro incubated in human serum and radiolabeled beta2M (125I-beta2 M) solution respectively. In these experiments, the materials were incubated in 125I-beta2 M solution and human serum at the appointed time ranging from 15 minutes to four hours at 37 degrees C, and then the amounts of 125I-beta2M and serum beta2M adsorbed by materials were measured by radioimmunoassay (RIA). In the 125I-beta2 M system, amounts of 125I-beta2M adsorbed by the materials decreased in sequence of PES-SO3 Na-II > PES-SO3Na-I > PES. In the serum system, amounts of beta2M adsorbed reached maximums at 30 minutes and the final adsorptions decreased in sequence of PES-SO3Na-II > PES-SO3Na-I > PES. Sulfonated PES removes beta2M more than PES does and the adsorption of beta2M increases with the increase in the degree of sulfonation. Its ability to remove significant amount of beta2M may result in less beta2M available for incorporation into amyloid. The use of PES-SO3Na membranes lessens the likelihood of dialysis-related amyloidosis (DRA) development, which remains a major source of morbidity for patients treated with long-term hemodialysis.

  2. Chondrogenesis on sulfonate-coated hydrogels is regulated by their mechanical properties.

    Science.gov (United States)

    Kwon, Hyuck Joon; Yasuda, Kazunori

    2013-01-01

    Many studies have demonstrated that sulfur-containing acidic groups induce chondrogenesis in vitro and in vivo. Recently, it is increasingly clear that mechanical properties of cell substrates largely influence cell differentiation. Thus, the present study investigated how mechanical properties of sulfonate-coated hydrogels influences chondrogenesis of mesenchymal stem cells (MSCs). Sulfonate-coated polyacrylamide gels (S-PAAm gels) which have the elastic modulus, E, of about 1, 15 and 150 kPa, were used in this study. MSCs cultured on the high stiffness S-PAAm gels (E=∼150 kPa) spread out with strong expression of stress fibers, while MSCs cultured on the low stiffness S-PAAm gels (E=∼1 kPa) had round shapes with less stress fibers but more cortical actins. Importantly, even in the absence of differentiation supplements, the lower stiffness S-PAAm gels led to the higher mRNA levels of chondrogenic markers such as Col2a1, Agc and Sox9 and the lower mRNA levels of an undifferentiation marker Sca1, indicating that the mechanical properties of S-PAAm gels strongly influence chondrogenesis. Blebbistatin which blocks myosin II-mediated mechanical sensing suppressed chondrogenesis induced by the low stiffness S-PAAm gels. The present study demonstrates that the soft S-PAAm gels effectively drive MSC chondrogenesis even in the absence of soluble differentiation factors and thus suggests that sulfonate-containing hydrogels with low stiffness could be a powerful tool for cartilage regeneration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Comb-shaped single ion conductors based on polyacrylate ethers and lithium alkyl sulfonate

    International Nuclear Information System (INIS)

    Sun Xiaoguang; Hou Jun; Kerr, John B.

    2005-01-01

    Comb-shaped single ion conductors have been synthesized by (1) sulfonation of small molecule chloroethyleneglycols, which, after ion exchange to the Li + salt were then converted to the acrylate by reaction with acryloyl chloride and copolymerized with polyethylene glycol monomethyl ether acrylate (Mn = 454, n = 8) (PAE 8 -co-E 3 SO 3 Li); (2) sulfonation of chloride end groups grafted on to prepolymers of polyacrylate ethers (PAE 8 -g-E n SO 3 Li, n = 2, 3). The highest conductivity at 25 deg. C of 2.0 x 10 -7 S cm -1 was obtained for the PAE 8 -co-E 3 SO 3 Li with a salt concentration of EO/Li = 40. The conductivity of PAE 8 -g-E 3 SO 3 Li is lower than that of PAE 8 -co-E 3 SO 3 Li at similar salt concentrations, which is related to the incomplete sulfonation of the grafted polymer that leads to a lower concentration of Li + . The addition of 50 wt.% of plasticizer, PC/EMC (1/1, v/v), to PAE 8 -g-E 2 SO 3 Li increases the ambient conductivity by three orders of magnitude, which is due to the increased ion mobility in a micro-liquid environment and an increase concentration of free ions as a result of the higher dielectric constant of the solvent. A symmetrical Li/Li cell with an electrolyte membrane consisting of 75 wt.% PC/EMC (1/1, v/v) was cycled at a current density of 100 μA cm -2 at 85 deg. C. The cycling profile showed no concentration polarization after a break-in period during the first few cycles, which was apparently due to reaction of the solvent at the lithium metal surface that reacted with lithium metal to form a stable SEI layer

  4. The Role of Moderate Static Magnetic Fields on Biomineralization of Osteoblasts on Sulfonated Polystryene Films

    Energy Technology Data Exchange (ETDEWEB)

    X Ba; M Hadjiargyrou; E DiMasi; Y Meng; M Simon; Z Tan; M Rafailovich

    2011-12-31

    We have investigated the effects of moderate static magnetic fields (SMFs) on murine MC3T3-E1 osteoblasts, and found that they enhance proliferations and promote differentiation. The increase in proliferation rates in response to SMFs was greater in cultures grown on partially sulfonated polytstyrene (SPS, degree of sulfonation: 33%) than in cultures grown on tissue culture plastic. We have previously shown that when the degree of sulfonation exceeded a critical value (12%) [1], spontaneous fibrillogenesis occured which allowed for direct observation of the ECM fibrillar organization under the influence of external fields. We found that the ECM produced in cultures grown on the SPS in the presence of the SMFs assembled into a lattice with larger dimensions than the ECM of the cultures grown in the absence of SMFs. During the early stages of the biomineralization process (day 7), the SMF exposed cultures also templated mineral deposition more rapidly than the control cultures. The rapid response is attributed to orientation of diamagnetic ECM proteins already present in the serum, which could then initiate further cellular signaling. SMFs also influenced late stage osteoblast differentiation as measured by the increased rate of osteocalcin secretion and gene expression beginning 15 days after SFM exposure. This correlated with a large increase in mineral deposition, and in cell modulus. GIXD and EDXS analysis confirmed early deposition of crystalline hydroxyapatite. Previous studies on the effects of moderate SMF had focused on cellular gene and protein expression, but did not consider the organization of the ECM fibers. Our ability to form these fibers has allowed us explore this additional effect and highlight its significance in the initiation of the biomineralization process.

  5. Xenobiotic action on steroid hormone synthesis and sulfonation the example of lead and polychlorinated biphenyls.

    Science.gov (United States)

    Romeo, L; Catalani, S; Pasini, F; Bergonzi, R; Perbellini, L; Apostoli, P

    2009-04-01

    In the present study, the metabolism of steroid hormones has been investigated to determine whether and how xenobiotics like lead (Pb) and polychlorinated biphenyls (PCBs) interfere with steroid hormone biotransformation in humans. Three groups of subjects were tested for concentration of urinary total steroids, 17-ketosteroids (n = 5), pregnane derivates (n = 6), 17-hydroxycorticosteroids (n = 11) and their sulfonated compounds: 14 workers exposed to lead, with a mean Pb blood concentration (PbB) of 29.21 microg/dl; 15 subjects exposed to PCBs, with a mean PCB blood concentration (PCBB) of 61.69 microg/l; a control group (n = 25). The urinary concentrations of 17-ketosteroids and 17-hydroxycorticosteroids were significantly lower in the PCB-exposed groups. There were significantly fewer sulfonated 17-hydroxycorticosteroids in the subjects exposed to PCBs as compared to the controls, while the percentage of sulfonated steroids was lower for both 17-ketosteroids and 17-hydroxycorticosteroids in the PCB-exposed subjects, but only for the 17-hydroxycorticosteroids in the group of subjects exposed to Pb (P < 0.05). Pregnane derivate urinary concentrations did not differ between the three groups. Our results suggest that PCBs and Pb act on steroid hormone metabolism with different effects and only partially using the same hormone pathways; they may cause changes in endogenous hormone homeostasis and interfere with the xenobiotic phase II of detoxification. PCBs interfere on a larger number of steroids and cause more significant effects than Pb. It is likely that different mechanisms are involved in steroid hormone metabolism interference.

  6. Aprendiendo de las Cuencas

    DEFF Research Database (Denmark)

    2015-01-01

    -existence of natural, rural, industrial and urban landscapes came about in a totally uncontrolled and unplanned fashion. The fuzzy limits between the different landscapes foreclose the possibility of identifying their areas of influence. The Cuencas are perceived as a mesh of opposing yet interconnected identities......Aprendiendo de las Cuencas (Learning from las Cuencas) research project, awarded with the EU Prize for Cultural Heritage / Europa Nostra Awards 2015, provides a new perspective of industrial cultural landscapes. Despite being focused on a local environment, the coal mining area of the Cuencas...

  7. Aprendiendo de las Cuencas

    DEFF Research Database (Denmark)

    2016-01-01

    -existence of natural, rural, industrial and urban landscapes came about in a totally uncontrolled and unplanned fashion. The fuzzy limits between the different landscapes foreclose the possibility of identifying their areas of influence. The Cuencas are perceived as a mesh of opposing yet interconnected identities......Aprendiendo de las Cuencas (Learning from las Cuencas) research project, awarded with the EU Prize for Cultural Heritage / Europa Nostra Awards 2015, provides a new perspective of industrial cultural landscapes. Despite being focused on a local environment, the coal mining area of the Cuencas...

  8. Learning from las Cuencas

    DEFF Research Database (Denmark)

    2016-01-01

    -existence of natural, rural, industrial and urban landscapes came about in a totally uncontrolled and unplanned fashion. The fuzzy limits between the different landscapes foreclose the possibility of identifying their areas of influence. The Cuencas are perceived as a mesh of opposing yet interconnected identities......Aprendiendo de las Cuencas (Learning from las Cuencas) research project, awarded with the EU Prize for Cultural Heritage / Europa Nostra Awards 2015, provides a new perspective of industrial cultural landscapes. Despite being focused on a local environment, the coal mining area of the Cuencas...

  9. Analizar las interacciones virtuales

    Directory of Open Access Journals (Sweden)

    Luis Gómez Encinas

    2003-11-01

    Full Text Available El propósito de este artículo es abordar una serie de cuestiones relacionadas con las interacciones virtuales. En concreto, nos centraremos en el IRC, los comúnmente llamados chats, para a partir de una crítica a ciertos posicionamientos analíticos, expresar la necesidad de indagar en esa faceta del ciberespacio desde el punto de vista de las relaciones sociales. Nuevas relaciones sociales, que acontecen en un espacio nuevo, y que por tanto se desarrollan bajo reglas y motivaciones que desbordan los viejos esquemas de observación.

  10. Brujas: las mujeres escriben

    OpenAIRE

    1982-01-01

    Esta publicación es un espacio para darle voz a la mujer: una voz desde la narrativa en femenino a través de la literatura, el cuento o la poesía; a través del ensayo que reflexiona por sus derechos, por su participación en la política, por su ciudadanía. Una voz que cuestiona y rechaza las imposiciones del sistema patriarcal, los roles, el sexismo y las relaciones interpersonales basadas en la violencia y la subordinación. A través de los diferentes textos, sus autoras realizan una invitaci...

  11. Tratamiento de las cefaleas

    OpenAIRE

    Martín Olivera, Raquel

    2006-01-01

    Las cefaleas son el grupo doloroso más frecuente en la práctica clínica y su tratamiento dista mucho de ser satisfactorio. Sin embargo, una buena respuesta es factible si se identifica correctamente el tipo de cefalea que se padece, se elige el fármaco más adecuado en una correcta dosis y vía de administracióny se comprende la historia natural de la enfermedad y las limitaciones del tratamiento. Se calcula que el 95% de la población mundial la presenta en algún momento de su vida. En España, ...

  12. Las Meninas transmedial

    DEFF Research Database (Denmark)

    Kacunko, Slavko

    2001-01-01

    might consist in extending the range of the ‘sample’, both to take in specific media and to cross their borders – and in taking seriously such artistic practice as founds on reproduction technology, doing them justice in our investigations. Meanwhile, trans-media interpretations of works of art created...... as a consequence. The approach of the presented monograph differs, while tentatively adopting certain elements of these approaches, from using Las Meniñas as an example to describe a possible trans-media point of view (Las Meniñas becoming not just a res interpretanda, but a [trans-media] instance for comparison...

  13. Benzyl­tributyl­ammonium 7-hydroxy­naphthalene-1-sulfonate

    Science.gov (United States)

    Sato, Yohei; Uta, Kazuya; Mizuguchi, Jin

    2009-01-01

    The title compound, C19H34N+·C10H7O4S−, is a charge-control agent used for toners in electrophotography. The anions form one-dimensional chains by O—H⋯O hydrogen bonds in a zigzag fashion along the c axis between the OH group of one anion and the sulfonate O atom of a neighboring anion. One of the n-butyl chains of the cation is disordered over two sites in a 0.77:0.23 ratio. PMID:21581926

  14. Syntheses, structures, thermal stabilities and luminescence of two new lead sulfonates with phosphonate, carboxylate and pyridine

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Ruibiao, E-mail: furb@fjirsm.ac.cn; Hu, Shengmin; Wu, Xintao

    2014-05-01

    Hydrothermal reactions of Pb{sup 2+} ion with disodium 4,4'-bis(2-sulfonatostyryl)biphenyl (Na{sub 2}L1), 4-pyridyl-CH{sub 2}N(CH{sub 2}COOH)(CH{sub 2}PO{sub 3} H{sub 2}) (H{sub 3}L2) and 4,4'-bipyridine (4,4'-bipy) afforded two new lead sulfonates, namely, [Pb{sub 4}(L1){sub 2}(HL2){sub 2}(H{sub 2}O)

  15. Structural, vibrational, thermal and optical studies of organic single crystal: Benzotriazolium p-toluene sulfonate (BTPTS)

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R. Ramesh; Sathya, P.; Gopalakrishnan, R., E-mail: krgkrishnan@yahoo.com [Department of Physics, College of Engineering, Guindy, Anna University, Chennai-600 025 (India)

    2016-05-06

    Benzotriazolium p-toluene sulfonate (BTPTS) was grown by solution growth technique. The powder X-ray diffraction analysis was carried out to evaluate crystal system of the compound. LeBail Profile fitting analysis was performed to extract the individual peak intensities. FTIR spectrum analysis was recorded to study vibration frequencies of the prepared organic salt. Thermal studies were carried out using TG-DSC analysis. Optical absorption and energy band gap of the title compound was evaluated by UV-Vis spectral study.

  16. Indole alkaloid sulfonic acids from an aqueous extract of Isatis indigotica roots and their antiviral activity

    Directory of Open Access Journals (Sweden)

    Lingjie Meng

    2017-05-01

    Full Text Available Six new indole alkaloid sulfonic acids (1–6, together with two analogues (7 and 8 that were previously reported as synthetic products, were isolated from an aqueous extract of the Isatis indigotica root. Their structures including the absolute configurations were determined by spectroscopic data analysis, combined with enzyme hydrolysis and comparison of experimental circular dichroism and calculated electronic circular dichroism spectra. In the preliminary assay, compounds 2 and 4 showed antiviral activity against Coxsackie virus B3 and influenza virus A/Hanfang/359/95 (H3N2, respectively.

  17. Effect of Poly (Sodium 4-Styrene Sulfonate) on the Morphology of Hydroxyapatite Particles

    OpenAIRE

    Esmaeilian Tari, Nesa; Kashani Motlagh, Mohammad Mahdi

    2009-01-01

    Nanorods hydroxyapatite, (HAP) C a 1 0 ( P O 4 ) 6 ( O H ) 2 is successfully prepared by water in oil microemulsion using, C a C L 2 and H 3 P O 4 (water phase), poly(sodium 4-styrene sulfonate) (PSSS) as template and cyclohexane as oil phase. The nano-structure of the product was studied by means of X-ray diffraction (XRD), Fourier transmission infrared spectrometer (FT-IR), scanning electron microscopy (SEM), and atomic force microscope (AFM). With this system, we could synthesize nano-part...

  18. Synthesis of Sulfones and Sulfonamides via Sulfinate Anions: Revisiting the Utility of Thiosulfonates.

    Science.gov (United States)

    Shyam, Pranab K; Jang, Hye-Young

    2017-02-03

    Simple and high-yielding strategies for the production of a variety of sulfones and sulfonamides, using thiosulfonates synthesized by copper-catalyzed aerobic dimerization, are reported. Although thiosulfonates are an old class of compound, practical methods for their synthesis and utilization have not been rigorously developed. In this study, we revisit the reactions of easily accessible thiosulfonates to form sulfinate anions. Because of the similar reactivity of thiosulfonates and metal sulfinates derived from toxic SO 2 , thiosulfinates are proposed to be stable, nontoxic alternatives to metal sulfinate salts.

  19. Electrodeposition of polypyrrole films on aluminum surfaces from a p-toluene sulfonic acid medium

    Directory of Open Access Journals (Sweden)

    Andréa Santos Liu

    2009-01-01

    Full Text Available Electrodeposition of polypyrrole films on aluminum from aqueous solutions containing p-toluene sulfonic acid and pyrrole was performed by cyclic voltammetry and galvanostatic technique. The influence of applied current density on the morphology of the films was studied by Scanning Electron Microscopy. The films displayed a cauliflower-like structure consisting of micro-spherical grains. This structure is related to dopand intercalation in the polymeric chain. Films deposited at higher current density were more susceptible to the formation of pores and defects along the polymeric chain than films deposited at lower current density. These pores allow the penetration of aggressive species, thereby favoring the corrosion process.

  20. Sulfonated Polyaniline Coated Mercury Film Electrodes for Voltammetric Analysis of Metals in Water

    Directory of Open Access Journals (Sweden)

    Denise Alves Fungaro

    2001-11-01

    Full Text Available The electrochemical polymerization of 2-aminobenzenesulfonic acid with and without aniline has been carried by cyclic potencial sweep in sulfuric acid solution at the glassy carbon electrode. The polymer and copolymer formed have been characterized voltammetrically. The sulfonated polyaniline coated mercury thin-film electrodes have been evaluated for use with anodic stripping voltammetry. The electrodes were tested and compared with a conventional thin-film mercury electrode. Calibration plots showed linearity up to 10-7 mol L-1. Detection limits for zinc, lead and cadmium test species are very similar at around 12 nmol L-1. Applications to analysis of waters samples are demonstrated.

  1. Simple and sensitive method for spectrofluorimetric determination of dodecyl benzene sulfonic acid sodium

    Science.gov (United States)

    Liu, Jinshui; Liu, Yan; Li, Peng; Wang, Lun

    2006-12-01

    The interaction of poly(diallyldimethyl ammonium chloride) (PDDA) with dodecyl benzene sulfonic acid sodium (DBS) has been studied by fluorescence spectra. The fluorescence of DBS can be greatly enhanced by addition of PDDA, owing to the interaction between PDDA and DBS. The enhancement intensity of fluorescence was proportional to the concentration of DBS over the range 2.5 × 10 -7 to 9.6 × 10 -5 mol L -1. Its detection limit is 3.5 × 10 -7 mol L -1. The method has high sensitivity and selectivity and was applied to the determination of trace amounts of DBS in water samples with satisfactory result.

  2. One-pot synthesis of aryl sulfones from organometallic reagents and iodonium salts.

    Science.gov (United States)

    Margraf, Natalie; Manolikakes, Georg

    2015-03-06

    A transition-metal-free arylation of lithium, magnesium, and zinc sulfinates with diaryliodonium salts is described. The sulfinic acid salts were prepared from the reaction of the corresponding organometallic reagents and sulfur dioxide. Combination of the three single steps (preparation of the organometallic compound, sulfinate formation, and arylation) leads to a one-pot sequence for the synthesis of aryl sulfones from simple starting materials. The chemoselectivity of unsymmetrical diaryliodonium salts has been investigated. Potential and limitations of this method will be discussed.

  3. Los cuidados y las mujeres en las familias Los cuidados y las mujeres en las familias

    Directory of Open Access Journals (Sweden)

    María Teresa Martín Palomo

    2008-12-01

    Full Text Available This article proposes a reflection on a debate that is generating an important theorical and empirical production: the care. In the first place, the specificity of care is explored from a point of view that includes, besides the material aspects, affective and moral ones. It stands out the complexity of care at the different dimensions that operate in this concept. Second: care is changing in our society, starting from the massive and durable arrival of women to the labor market. In the families women are mainly responsible or caring for aged population, children and other fragile people. As to this moment care has not been reorganized among the genders, they have been the women of different generations who have articulated its solidarities with available state help or appealing to the market to cover the necessities of its relatives. Howevwe, the graving deficit in the provision of family care seems to approach a point of not sustainability in the near future. Propoal of “social care” offer institutional articulation between private solidarities and public duties in the allotment of family care so tha society in general can bear to the participation of women in the labour work. This implying the return of moral responsibility in the politics of care.Este artículo propone una reflexión sobre uno de los debates que está generando una importante producción teórica y empírica en los últimos años: los cuidados. Para ello, en primer lugar, se explora la especificidad de los cuidados ampliando el enfoque desde un punto de vista que incluya, además de los aspectos materiales, aspectos afectivos y morales. Se destaca la transversalidad y enorme complejidad de los cuidados por las diferentes dimensiones que operan en dicho concepto. En segundo lugar, se revisa como se están reestructurando los cuidados en nuestra sociedad a partir de las transformaciones que ha provocado la llegada masiva y duradera de mujeres al mercado laboral, a la par

  4. THE SULFONATION STUDY OF REACTION MECHANISM ON PAPAVERINE ALKALOID BY GC-MS AND FT-IR

    Directory of Open Access Journals (Sweden)

    I Made Sudarma

    2010-06-01

    Full Text Available The aim of this research was to prove theoretical mechanism reaction on the sulfonation of papaverine alkaloid and the result could be used as a reference on the transformation of these alkaloid to the other derivatives. Theoriticaly sulfonation of papaverine (1 by HO-SO2Cl could produced papaverine sulfonyl chloride (1a. The formation of this product was analyzed by analytical thin layer chromatography GC-MS, and FT-IR. These analysis showed the formation of product (1a more favorable than the other. Tlc showed product (1a less polar than papaverine, and supported by GC-MS and infrared which showed molecular ion at m/z 412 due to the presence of -SO2Cl and vibration at 1153,4 dan 1265,2 Cm-1 due to absorption of sulfonyl group.   Keywords: reaction mechanism, sulfonation, papaverine alkaloid.

  5. Reaction of lithium diethylamide with an alkyl bromide and alkyl benzenesulfonate: origins of alkylation, elimination, and sulfonation.

    Science.gov (United States)

    Gupta, Lekha; Ramírez, Antonio; Collum, David B

    2010-12-17

    A combination of NMR, kinetic, and computational methods are used to examine reactions of lithium diethylamide in tetrahydrofuran (THF) with n-dodecyl bromide and n-octyl benzenesulfonate. The alkyl bromide undergoes competitive S(N)2 substitution and E2 elimination in proportions independent of all concentrations except for a minor medium effect. Rate studies show that both reactions occur via trisolvated-monomer-based transition structures. The alkyl benzenesulfonate undergoes competitive S(N)2 substitution (minor) and N-sulfonation (major) with N-sulfonation promoted at low THF concentrations. The S(N)2 substitution is shown to proceed via a disolvated monomer suggested computationally to involve a cyclic transition structure. The dominant N-sulfonation follows a disolvated-dimer-based transition structure suggested computationally to be a bicyclo[3.1.1] form. The differing THF and lithium diethylamide orders for the two reactions explain the observed concentration-dependent chemoselectivities.

  6. Las TIC como fuente de ventaja competitiva en las PYMES

    OpenAIRE

    Álvaro Fernando Moncada Niño; Martha Lucía Oviedo Franco

    2013-01-01

    Desde su aparición, las Tecnologías de la Información y las Comunicaciones (TIC) se han convertido en un recurso fundamental de las empresas para competir en la mayoría de las industrias, generalizando el planteamiento de que son fuente de ventaja competitiva. Pero realmente, ¿cuándo las TIC son fuente potencial de ventaja competitiva para las pymes? ¿Bajo qué condiciones se logra que contribuyan a generar valor y mejorar su posición competitiva? ¿Qué características deben cumplir para alcanz...

  7. Sulfonation and sialylation of gonadotropins in women during the menstrual cycle, after menopause, and with polycystic ovarian syndrome and in men.

    Science.gov (United States)

    Wide, Leif; Naessén, Tord; Sundström-Poromaa, Inger; Eriksson, Karin

    2007-11-01

    More basic isoforms of LH and FSH appear in blood at midcycle and more acidic after menopause. The LH isoforms are more basic in women with polycystic ovarian syndrome (PCOS). These charge alterations may reflect differences in the number of two negatively charged residues on the gonadotropins: sialic acid and sulfonated N-acetylgalactosamine, residues that modulate the half-life of the gonadotropins in blood. The objective of the study was to determine the contributions of sialic acid and sulfonated N-acetylgalactosamine and sialic acid on LH and FSH to the observed alterations in charge. Serum samples were obtained from 59 young women with regular cycles, nine postmenopausal women, 12 women with PCOS, and 40 young men. The number of sulfonated N-acetylgalactosamine and sialic acid residues per LH and FSH molecule in serum and the distributions of molecules with 0-1-2-3-4 sulfonated residues were determined by electrophoretic analyses before and after removal of sialic acid. Considerably decreased sulfonation of LH was found at midcycle and in women with PCOS concomitant with slightly increased sialylation. The sulfonation of LH increased in the luteal phase, and the sialylation was highest after menopause for both hormones. The frequencies of sulfonated LH and FSH isoforms were directly related (P sulfonated residues on serum gonadotropins are suggested to reflect alterations in the isoform composition of the hormones secreted by the pituitary, resulting in modulations of their biological properties, such as half-life in blood.

  8. Zorrozaurre: las horas contadas

    OpenAIRE

    Llamas Sánchez, Miguel

    2016-01-01

    Zorrozaurre, las horas contadas, trata sobre el distrito bilbaíno protagonista de un macroproyecto urbanístico, centrándose en su pasado industrial y algunas de sus construcciones más emblemáticas.

  9. Las competencias emocionales

    Directory of Open Access Journals (Sweden)

    Rafael Bisquerra Alzina

    2007-01-01

    Full Text Available El concepto de competencia está en revisión debido a su complejidad. Hay diversas categorías de competencias: técnicas, profesionales, participativas, personales, básicas, clave, genéricas, transferibles, emocionales, socio-emocionales, etc. En este trabajo se toman en consideración las competencias emocionales, entendidas como un subconjunto de las competencias personales. Se exponen los trabajos en torno a estas competencias y se aporta una conceptualización y una sistemática estructurada en cinco grandes bloques: conciencia emocional, regulación emocional, autonomía emocional, competencia social, habilidades de vida y bienestar. Se hace referencia a las aplicaciones de las competencias emocionales en la empresa, la salud y la educación. De cara a la clarificación de conceptos, se establece la distinción entre inteligencia emocional, competencia emocional y educación emocional.

  10. de las mujeres

    Directory of Open Access Journals (Sweden)

    Elena Margarita Cacheux Pulido

    2003-01-01

    Full Text Available El feminismo chicano tiene múltiples venas que nutrieron el pensamiento ideológico, político y estratégico durante todo el siglo pasado. Una de ellas se forma por los encuentros locales, nacionales e internacionales que sirvieron de plataforma para comunicar, entre mujeres, las propias necesidades para el desarrollo y la liberación de la injusticia, intolerancia y desdén. Las mujeres han luchado por medio de sindicatos y movimientos sociales para plantear justas demandas, entre otras, educación, igual salario por igual trabajo, bienestar, permiso de maternidad, cuidado infantil, autodeterminación, información sexual, igualdad en la participación política y liderazgo. Con el avance teórico en las cuestiones de raza, clase, minorías étnicas y feminismo lésbico, se desarrolló la identidad de la nueva chicana a la luz de la emancipación de las mujeres.

  11. para las lenguas

    Directory of Open Access Journals (Sweden)

    Manuel Tost Planet

    2005-01-01

    Full Text Available La publicación del Marco común europeo de referencia para las lenguas, del Consejo de Europa –aún poco conocido en nuestro país– está teniendo ya una notable influencia en todos los ámbitos de la enseñanza de las lenguas y de un modo particular en la elaboración de materiales de nueva generación para el aprendizaje de las lenguas extranjeras. Tras presentar elementos contextuales de la situación del FLE en nuestro país, que tienen, pensamos, una cierta relevancia, en esta contribución se describen precisamente algunos aspectos fragmentarios de dicho Marco y se evocan, por último, los principales ejes en torno a los cuales se mueve la actual innovación didáctica, en lo que se refiere más concretamente a las actividades de aprendizaje en el aula de idiomas.

  12. Influence of co-substrates in the anaerobic degradation of an anionic surfactant

    Directory of Open Access Journals (Sweden)

    D. Y. Okada

    2013-09-01

    Full Text Available The removal of linear alkylbenzene sulfonate (LAS was evaluated in a UASB reactor using short-chain alcohols (ethanol and methanol and complex co-substrate (yeast extract. Using only methanol and ethanol as co-substrates resulted in removal of LAS between 30 and 41%. At the end, addition of a complex substrate (yeast extract increased the removal of LAS to 50%. During the assay, water supply aeration increased the volatile fatty acid of the effluent (70 mg HAc.L-1 and decreased the removal of LAS (from 40 to 30%. According to the fluorescence in situ hybridization (FISH results, the amount of Archaea decreased due to water supply aeration (from 64 to 48%. Furthermore, addition of complex co-substrate increased the total anaerobic bacteria and methanogenic archaea content (three and four log units, respectively, which were estimated using the most probable number technique.

  13. Antibacterial Activities of Surfactants in the Laundry Detergents and Isolation of the Surfactant Resistant Aquatic Bacteria.

    Science.gov (United States)

    Maehara, Yoko; Miyoshi, Shin-Ichi

    2017-01-01

     Linear alkylbenzene sulfonate (LAS) and polyoxyethylene lauryl ether (POLE) are major surfactants contained in the laundry detergents. In the present study, the antibacterial activities of the surfactants to aquatic microorganisms were compared. When freshwater samples from a small river in Okayama city were treated with each of the surfactants, only LAS showed the significant antibacterial activity. Several strains, which survived after the treatment with 2.0% LAS, were isolated and identified by sequencing of 16S rDNA. All strains were classified into the family Enterobacteriaceae. However, this family was not a major member of the aquatic microflora, suggesting that the bacteria in Enterobacteriaceae have a common property of LAS-resistance in the river water.

  14. Regioselectivity of vinyl sulfone based 1,3-dipolar cycloaddition reactions with sugar azides by computational and experimental studies.

    Science.gov (United States)

    Sahu, Debashis; Dey, Santu; Pathak, Tanmaya; Ganguly, Bishwajit

    2014-04-18

    DFT (M06-L) calculations on the transition state for the 1,3-dipolar cycloadditions between substituted vinyl sulfones with sugar azide have been reported in conjunction with new experimental results, and the origin of reversal of regioselectivity has been revealed using a distortion/interaction model. This study provides the scientific justification for combining organic azides with two different types of vinyl sulfones for the preparation of 1,5-disubstituted 1,2,3-triazoles and 1,4-disubstituted triazolyl esters under metal-free conditions.

  15. Silica-supported sulfonic acids as recyclable catalyst for esterification of levulinic acid with stoichiometric amounts of alcohols

    Directory of Open Access Journals (Sweden)

    Raimondo Maggi

    2016-10-01

    Full Text Available Converting biomass into value-added chemicals holds the key to sustainable long-term carbon resource management. In this context, levulinic acid, which is easily obtained from cellulose, is valuable since it can be transformed into a variety of industrially relevant fine chemicals. Here we present a simple protocol for the selective esterification of levulinic acid using solid acid catalysts. Silica supported sulfonic acid catalysts operate under mild conditions and give good conversion and selectivity with stoichiometric amounts of alcohols. The sulfonic acid groups are tethered to the support using organic tethers. These tethers may help in preventing the deactivation of the active sites in the presence of water.

  16. Preparation of Highly Sulfonated Ultra-Thin Proton-Exchange Polymer Membranes for Proton Exchange Membrane Fuel Cells

    Science.gov (United States)

    Jiang, Zhongqing; Meng, Yuedong; Jiang, Zhong-Jie; Shi, Yicai

    Sulfonated ultra-thin proton-exchange polymer membrane carrying pyridine groups was made from a plasma polymerization of styrene, 2-vinylpyridine, and trifluoromethanesulfonic acid by after-glow capacitively coupled discharge technique. Pyridine groups tethered to the polymer backbone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups of proton exchange membrane. It shows that the method using present technology could effectively depress the degradation of monomers during the plasma polymerization. Spectroscopic analyses reveal that the obtained membranes are highly functionalized with proton exchange groups and have higher proton conductivity. Thus, the membranes are expected to be used in direct methanol fuel cells.

  17. Development and characterization of acid-doped polybenzimidazole/sulfonated polysulfone blend polymer electrolytes for fuel cells

    DEFF Research Database (Denmark)

    Hasiotis, C.; Li, Qingfeng; Deimede, V.

    2001-01-01

    Polymeric membranes from blends of sulfonated polysulfones (SPSF) and polybenzimidazole (PBI) doped with phosphoric acid were developed as potential high-temperature polymer electrolytes for fuel cells and other electrochemical applications. The water uptake and acid doping of these polymeric...... membranes were investigated. Ionic conductivity of the membranes was measured in relation to temperature, acid doping level, sulfonation degree of SPSF, relative humidity, and blend composition. The conductivity of SPSF was of the order of 10/sup -3/ S cm/sup -1/. In the case of blends of PBI and SPSF...

  18. Silica-supported sulfonic acids as recyclable catalyst for esterification of levulinic acid with stoichiometric amounts of alcohols.

    Science.gov (United States)

    Maggi, Raimondo; Shiju, N Raveendran; Santacroce, Veronica; Maestri, Giovanni; Bigi, Franca; Rothenberg, Gadi

    2016-01-01

    Converting biomass into value-added chemicals holds the key to sustainable long-term carbon resource management. In this context, levulinic acid, which is easily obtained from cellulose, is valuable since it can be transformed into a variety of industrially relevant fine chemicals. Here we present a simple protocol for the selective esterification of levulinic acid using solid acid catalysts. Silica supported sulfonic acid catalysts operate under mild conditions and give good conversion and selectivity with stoichiometric amounts of alcohols. The sulfonic acid groups are tethered to the support using organic tethers. These tethers may help in preventing the deactivation of the active sites in the presence of water.

  19. Membranes of polyindene sulfonated and PVA for use as polymer electrolyte; Membranas mistas de poli(indeno) sulfonado e PVA para uso como eletrolito polimerico

    Energy Technology Data Exchange (ETDEWEB)

    Loser, N.; Silva, B.B.R. da; Brum, F.J.B.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul - Escola de Engenharia, Porto Alegre, RS (Brazil)

    2010-07-01

    This study is focused on developing polymer poly electrolytes for fuel cell PEM and aims to evaluate the efficiency of sulfonated polyindene as A polymer electrolyte in blends with poly (vinyl alcohol) (PVA). For this, polyindene synthesized in the lab was functionalized with sulfonic groups (-SO{sub 3}H), using as sulfonation agent acetyl sulfate in 1,2-dichloroethane. The membranes of sulfonated polyindene (SPInd) and PVA were prepared in aqueous medium, using glutaraldehyde as a PVA cross linker. The membranes SPInd/PVA were evaluated on the content of sulfonic groups, ion exchange capacity (IEC), degree of swelling in water and thermal stability (TGA). Electrochemical impedance analysis was used for ionic conductivity evaluation and DMA for the mechanical strength of the membranes. Preliminary results show that the membranes showed ion exchange capacity about 3.2 m equiv/g and degree of swelling in water of 550%. (author)

  20. Synthesis and characterization of sulfonated polymers for ionomeric membranes based on styrene copolymers; Sintese e caracterizacao de precursores sulfonados para membranas polimericas a base de copolimeros estirenicos

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.M.; Forte, M.M.C.; Amico, S.C. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Escola de Engenharia. Lab. de Materiais Polimericos (LAPOL)], e-mail: crismbecker@yahoo.com.br, e-mail: mmcforte@ufrgs.br, e-mail: amico@ufrgs.br; Vargas, J.V.C. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica], e-mail: jvargas@demec.ufpr.br

    2006-07-01

    Polymer electrolyte membrane fuel cell (PEMFC) have emerged strongly as a viable alternative for power source owing to their high energy efficiency and environmental friendliness. Currently, Nafion is the most frequently used membrane even though it has a high cost. The objective of this work is to synthesize sulfonated polymers, based on styrene copolymers, with different sulfonation degrees as an alternative material for fuel cell membranes. Acetyl sulfate was used to carry out the sulfonation and the resulting polymers were characterized by Fourier Transform Infra-red (FTIR), thermogravimetric analysis (TGA) and degree of substitution or sulfonation (DS). The polyelectrolytes were evaluated regarding their ion exchange capacity (IEC) and conductivity. The results demonstrated that increasing the sulfonic acid content of the polymer results in higher IEC, conductivity and water uptake. (author)

  1. Solubility of sodium 4-nitrotoluene-2-sulfonate in (propanol + water) and (ethylene glycol + water) systems

    International Nuclear Information System (INIS)

    Wang Lingxin; Yu Xiaoman; Xia Qing; Zhang Fengbao; Zhang Guoliang

    2012-01-01

    Highlights: → The solubilities of NTSNa in 2 binary solvent mixtures are experimental determined. → The E-NRTL model and modified Apelblat model are used to describe systems. → The effect of solvents on the reaction of oxidation NTS to DNS was discussed. - Abstract: The solubility data of sodium 4-nitrotoluene-2-sulfonate (NTSNa) in aqueous organic solutions (propanol + water) and (ethylene glycol + water) were measured at temperatures ranging from (290 to 351) K using a dynamic method. The mole fraction of water in solvent mixtures ranged from 0 to 0.8. The solubility values are correlated with the electrolyte non-random two-liquid (E-NRTL) model. From the results obtained, the E-NRTL model provides a satisfactory mathematical representation of the experimental results for the (NTSNa + propanol + water) system and an unsatisfactory result for the (NTSNa + ethylene glycol + water) system. Thus, the modified Apelblat model is applied to describe the (NTSNa + ethylene glycol + water) system also. The calculated (solid + liquid) equilibrium temperatures with the modified Apelblat model are in good agreement with the experimental results. The root-mean-square deviations of solubility temperature varied from (0.08 to 0.94) K for two models. The effect of different aqueous organic solutions on the reaction of oxidation 4-nitrotoluene-2-sulfonic acid (NTS) to 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNS) was discussed.

  2. Bioseparation of papain from Carica papaya latex by precipitation of papain-poly (vinyl sulfonate) complexes.

    Science.gov (United States)

    Braia, Mauricio; Ferrero, Maximiliano; Rocha, María Victoria; Loureiro, Dana; Tubio, Gisela; Romanini, Diana

    2013-09-01

    The formation of insoluble complexes between enzymes and polyelectrolytes is a suitable technique for isolating these biomolecules from natural sources, because it is a simple and rapid technique that allows the concentration of the protein. This technique can be used in most purification protocols at the beginning of the downstream process. The aim of this investigation is to isolate papain from Carica papaya latex by precipitation of insoluble complexes between this enzyme and poly (vinyl sulfonate). The papain-poly (vinyl sulfonate) complex was insoluble at pH lower than 6, with a PVS/PAP stoichiometric ratio of 1:279. Ionic strength affected the complex formation. The presence of the polymer increased the enzymatic activity and protected the enzyme from autodegradation. The optimal conditions for the formation of insoluble papain-polyelectrolyte complex formation were applied to C. papaya latex and a high recovery was obtained (around 86%) and a purification factor around 2. This method can be applied as an isolation method of papain from C. papaya latex or as a first step in a larger purification strategy. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Animated sulfonated or sulformethylated lignins as cement fluid loss control additives

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, P.

    1991-05-07

    This patent describes a method of cementing a zone in a well penetrating a subterranean formation comprising injecting down the well and positioning in the zone to be cemented a hydraulic aqueous cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and a fluid loss control additive comprising from about 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been aminated by reacting it with between about 2-5 moles of a polyamine and 2-5 moles of an aldehyde per 1,000g of the lignin, and 0.1 to 1.5 parts of a compound selected from the group consisting of sodium carbonate, sodium metasilicate, sodium phosphate, sodium sulfite and sodium naphthalene sulfonate and a combination thereof.

  4. Preparation of sulfonic acid-containing rubbers from natural rubber vulcanizates

    Science.gov (United States)

    Poonsawat, Worapong; Poompradub, Sirilux; Ngamcharussrivichai, Chawalit

    2014-06-01

    In this work, a series of sulfonic acid-containing rubbers were prepared by aqueous phase oxidation of natural rubber vulcanizates in the presence of hydrogen peroxide (H2O2) and formic acid (HCOOH). The starting vulcanizates were neatly prepared via an efficient vulcanization (EV) system by varying mass ratio of N-cyclohexyl-2-benzothiazole sulfonamide (CBS), as an accelerator, to sulfur. The oxidation conditions were controlled at the molar ratio of H2O2: HCOOH = 1:1, the concentration of H2O2 = 15 wt.%, the temperature = 50 °C, and the reaction time = 3 h. The rubber materials before and after the oxidation were characterized for their physicochemical properties by using Fourier transform infrared spectroscopy, bomb calorimetry, acid-base titration and swelling measurements. The results indicated the presence of sulfonic acid group in the oxidized rubbers, generated by the oxidative cleaves of sulfide crosslinks in the rubber vulcanizates. The oxidation decreased the sulfur content of the rubber in which the level of sulfur loss was determined by the CBS/sulfur ratio. Moreover, the acidity of the oxidized products was correlated with the amount of sulfur remaining.

  5. Well-Shaped Sulfonic Organosilica Nanotubes with High Activity for Hydrolysis of Cellobiose

    Directory of Open Access Journals (Sweden)

    Jing Sun

    2017-04-01

    Full Text Available Sulfonic organosilica nanotubes with different acidity densities could be synthesized through the co-condensation of ethenyl- or phenylene-bridged organosilane and 3-mercaptopropyltrimethoxysilane followed by sulfhydryl (–SH oxidation. Transmission electron microscopy (TEM analysis and nitrogen adsorption-desorption experiment clearly exhibit the hollow nanotube structures with the diameters of about 5 nm. The compositions of the nanotube frameworks are confirmed by solid state 13C nuclear magnetic resonance (NMR while X-ray photoelectron spectroscopy (XPS shows that about 60–80% of SH groups were oxidized to sulfonic acid (SO3H. The acid contents were measured by both elemental analysis (CHNS mode and acid-base titration experiment, which revealed that the acid density was in the range of 0.74 to 4.37 μmol·m−2 on the solid. These nanotube-based acid catalysts exhibited excellent performances in the hydrolysis of cellobiose with the highest conversion of 92% and glucose selectivity of 96%. In addition, the catalysts could maintain high activity (65% conversion with 92% selectivity even after six recycles.

  6. Synthetic approach of norbadione A: new preparation of alcohols from sulfones and boron compounds

    International Nuclear Information System (INIS)

    Billaud, C.

    2005-12-01

    The synthetic approach of norbadione A, a pigment from mushrooms related to pulvinic acids, was studied. This compound has the property to complex caesium and has shown an antioxidant activity. The first strategy, based on a double Suzuki-Miyaura coupling between a naphtho-lactone with two boron functions and two pulvinic moieties with a triflate was unsuccessful and has shown a deactivating effect of the lactone. Modifications aimed to inhibit the electro-attracting character of the lactone permitted to obtain a bis(coupled) product with a poor yield. A second approach based on a the cyclization of enol aryl-acetates was studied in order to build the pulvinic moiety in several steps. The important reaction of introduction of an alkyl-acetate from a triflate was realised by a palladium-mediated coupling. The cyclization attempts carried out using a naphthalenic compound allowed us to isolate a monocyclised product. A parallel study was to first build a tetronic moiety and then to construct the exocyclic double bond by a method developed in the laboratory for the preparation of an iodated pulvinic compound. Finally, a new preparation of alcohols from sulfones and boron compounds was developed. Two known reactions in the chemistry of boron were combined. The first one is the reaction between anions of sulfones and tri-alkyl-boranes, the second one is a thermal isomerization which places the boron atom in a terminal position. A new preparation of primary alcohols was thus carried out. (author)

  7. The fluidity of fly ash-cement paste containing naphthalene sulfonate superplasticizer

    Energy Technology Data Exchange (ETDEWEB)

    Pipat Termkhajornkit; Toyoharu Nawa [Hokkaido University, Sapporo (Japan). Division of Structural and Geotechnical Engineering, Graduate School of Engineering

    2004-06-01

    The zeta potential measurement indicated that the surface potential of fly ash was different from ordinary Portland cement (OPC) in both sign and value. Hence, the Derjaguin-Landau-Verway-Overbeek (DLVO) theory for dispersion-flocculation of heterogeneous particles with different surface potentials was applied to explain the influence of fly ash on the rheology of cement paste containing naphthalene sulfonate superplasticizer. For the fly ash-cement paste without superplasticizer, the sign of zeta potential of fly ash was different from OPC. Thus, the extent of the potential energy barrier between particles was small or even showed negative value, and the change in the rheology of the fly ash-cement paste was mainly dependent on the bulk solid volume of fly ash, which was related to available free water for fluidizing paste. For the fly ash-cement paste with naphthalene sulfonate superplasticizer, fly ash and cement had the same sign and dispersed well due to higher potential barrier. The extent of potential energy barrier depended on the absolute value of surface potential, which was represented by a function of the amount of adsorbed superplasticizer. The bulk solid volume of fly ash also affected the change in flow ability, but the effect of potential energy barrier between particles was superior to that of the bulk solid volume of fly ash.

  8. Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

    International Nuclear Information System (INIS)

    Kordoghli, Bessem; Khiari, Ramzi; Mhenni, Mohamed Farouk; Sakli, Faouzi; Belgacem, Mohamed Naceur

    2012-01-01

    Highlights: ► In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. ► The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. ► We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO 3 H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

  9. Quantitative structure–reactivity study on sulfonation of amines, alcohols and phenols

    Directory of Open Access Journals (Sweden)

    Abolghasem Beheshti

    2017-05-01

    Full Text Available Quantitative structure–reactivity relationship (QSRR can be considered as a variant of quantitative structure property relationship (QSPR studies, where the chemical reactivity of reactants in a specified chemical reaction is related to chemical structure. As follows, the sulfonation reaction yield of 24 amines, alcohols and phenols with sulfonyl chloride was studied by QSRR. Quantum chemical calculations (b3lyp/6-31+g (d were carried out to obtain the optimized geometry. The suitable set of molecular descriptors was calculated to represent the molecular structures of compounds, such as constitutional, topological, geometrical, electrostatic and quantum-chemical descriptors. The genetic algorithm (GA was applied to select the variables that resulted in the best-fitted models. After the variable selection, multiple linear regression (MLR was utilized to construct linear QSRR models. The maximum relative error in prediction (5.26 showed that the predictive ability of the model was satisfactory and it can be used for designing similar reactants with efficient sulfonation reaction.

  10. Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kordoghli, Bessem [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Khiari, Ramzi, E-mail: khiari_ramzi2000@yahoo.fr [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France); Mhenni, Mohamed Farouk [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Sakli, Faouzi [Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Belgacem, Mohamed Naceur [LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. Black-Right-Pointing-Pointer The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. Black-Right-Pointing-Pointer We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO{sub 3}H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

  11. Modification of the cellulosic component of hemp fibers using sulfonic acid derivatives: Surface and thermal characterization.

    Science.gov (United States)

    George, Michael; Mussone, Paolo G; Bressler, David C

    2015-12-10

    The aim of this study was to characterize the surface, morphological, and thermal properties of hemp fibers treated with two commercially available, inexpensive, and water soluble sulfonic acid derivatives. Specifically, the cellulosic component of the fibers were targeted, because cellulose is not easily removed during chemical treatment. These acids have the potential to selectively transform the surfaces of natural fibers for composite applications. The proposed method proceeds in the absence of conventional organic solvents and high reaction temperatures. Surface chemical composition and signature were measured using gravimetric analysis, X-ray photoelectron spectroscopy (XPS) and Fourier transform infra-red spectroscopy (FTIR). XPS data from the treated hemp fibers were characterized by measuring the reduction in O/C ratio and an increase in abundance of the C-C-O signature. FTIR confirmed the reaction with the emergence of peaks characteristic of disubstituted benzene and amino groups. Grafting of the sulfonic derivatives resulted in lower surface polarity. Thermogravimetric analysis revealed that treated fibers were characterized by lower percent degradation between 200 and 300 °C, and a higher initial degradation temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effects of bleach activator, sodium alkyl acyloxybenzene sulfonate, on house dust mites (Dermatophagoides farinae).

    Science.gov (United States)

    Tobe, Seiichi; Kamezaki, Hiroki; Watanabe, Toshiyuki; Takaoka, Hiromitsu; Sakaguchi, Masahiro

    2010-01-01

    House dust mites (Dermatophagoides farinae) in bedding and clothes are a major allergen. However, house dust mites cannot be killed by general washing conditions under 50 degrees C. Therefore, low-temperature washing conditions must be improved to eliminate house dust mites. Sodium alkyl acyloxybenzene sulfonate (OBS) is a bleach activator that is used to intensify the bleaching effects of some laundry products. The purpose of this study was to evaluate the effect of OBS on the elimination of house dust mites in low-temperature washing conditions. D. farinae was soaked in solutions containing different types of OBS for various durations and at various temperatures. The miticidal effects of the various washing conditions were also evaluated for D. farinae. Then sodium lauroyloxybenzene sulfonate (OBS-12) produced the highest D. farinae mortality rate among the OBS solutions that were examined and had a stronger miticidal effect than available chlorine under general washing conditions. OBS exhibited miticidal effects under general washing conditions at low temperatures. Since OBS is already used as an additive in some laundry products to increase the bleaching activity, OBS can be easily used to kill house dust mites under general washing conditions.

  13. Hierarchical Porous Interlocked Polymeric Microcapsules: Sulfonic Acid Functionalization as Acid Catalysts

    Science.gov (United States)

    Wang, Xiaomei; Gu, Jinyan; Tian, Lei; Zhang, Xu

    2017-03-01

    Owing to their unique structural and surface properties, mesoporous microspheres are widely applied in the catalytic field. Generally, increasing the surface area of the specific active phase of the catalyst is a good method, which can achieve a higher catalytic activity through the fabrication of the corresponding catalytic microspheres with the smaller size and hollow structure. However, one of the major challenges in the use of hollow microspheres (microcapsules) as catalysts is their chemical and structural stability. Herein, the grape-like hypercrosslinked polystyrene hierarchical porous interlocked microcapsule (HPIM-HCL-PS) is fabricated by SiO2 colloidal crystals templates, whose structure is the combination of open mouthed structure, mesoporous nanostructure and interlocked architecture. Numerous microcapsules assembling together and forming the roughly grape-like microcapsule aggregates can enhance the structural stability and recyclability of these microcapsules. After undergoing the sulfonation, the sulfonated HPIM-HCL-PS is served as recyclable acid catalyst for condensation reaction between benzaldehyde and ethylene glycol (TOF = 793 h-1), moreover, exhibits superior activity, selectivity and recyclability.

  14. Enhanced Capacity of Polypyrrole/Anthraquinone Sulfonate/Graphene Composite as Cathode in Lithium Batteries

    International Nuclear Information System (INIS)

    Yang, Yang; He, Kuangchi; Yan, Peng; Wang, Dan; Wu, Xiaoyan; Zhao, Xin; Huang, Zilong; Zhang, Chunming; He, Dannong

    2014-01-01

    Highlights: • A polypyrrole (PPy)/anthraquinone sulfonate (AQS)/reduced graphene oxide (r-GO) composite was obtained via a facile electrochemical route. • A great enhancement in electrochemical performance was obtained for PPy/AQS/r-GO due to a remarkable combination of the redox property of AQS and the conductivity of r-GO. • The composite electrode delivered a specific discharge capacity of 127.2 mAh g −1 with a ca. 100% coulombic efficiency at 0.1 A g −1 . - Abstract: A facile electrochemical route was applied to prepare polypyrrole (PPy)/anthraquinone sulfonate (AQS)/reduced graphene oxide (r-GO) composite. The as-synthesized composite showed an interconnected porous structure, which is related to the competitive relationship between two dopants. The cyclic voltammograms and electrochemical impedance spectra confirmed that the presence of highly conductive r-GO in PPy matrix ensured an efficient redox reaction obtained for redox-active AQS. As a result, the PPy/AQS/r-GO composite exhibited an enhanced specific capacity of 127.2 mAh g −1 with ca. 100% coulombic efficiency at 0.1 A g −1 . Furthermore, the superior rate capability and cycling stability were also observed for PPy/AQS/r-GO, compared to AQS doped PPy. It is possible to adopt this co-dopants system for creating electro-active polymer materials with high capacities that are comparable to that of conventional inorganic intercalation electrode materials

  15. Aqueous preparation of polyethylene glycol/sulfonated graphene phase change composite with enhanced thermal performance

    International Nuclear Information System (INIS)

    Li, Hairong; Jiang, Ming; Li, Qi; Li, Denian; Chen, Zongyi; Hu, Waping; Huang, Jing; Xu, Xizhe; Dong, Lijie; Xie, Haian; Xiong, Chuanxi

    2013-01-01

    Highlights: • We report an aqueous preparation technique of PEG/graphene phase change composite. • Hydrophilic sulfonated graphene (SG) nanosheets were synthesized. • Large increase in thermal conductivity is attained at low SG loading. • High latent heat is retained due to the low filler loading. • Affinity between SG and PEG contributes to the enhanced thermal performance. - Abstract: A polyethylene glycol (PEG)/sulfonated graphene (SG) phase change composite with enhanced thermal performance was prepared by solution processing in aqueous medium. It is remarkable that the addition of only 4 wt.% of SG to PEG could lead to a four times higher increase in thermal conductivity and a slight decrease in the phase change enthalpy, which is attributed to the formation of efficient thermal conductive network within the PEG matrix relevant to the excellent thermal property and unique 2-dimensional morphology of graphene as well as strong interface affinity between PEG matrix and SG nanosheets. The aqueous preparation technique is expected to pioneer a new way to prepare environment friendly organic phase change materials, and the production of PEG/SG composites is potentially scalable due to the facile fabricating process

  16. Tissue-specific concentrations and patterns of perfluoroalkyl carboxylates and sulfonates in East Greenland polar bears.

    Science.gov (United States)

    Greaves, Alana K; Letcher, Robert J; Sonne, Christian; Dietz, Rune; Born, Erik W

    2012-11-06

    Several perfluoroalkyl carboxylates (PFCAs) and perfluoroalkyl sulfonates (PFSAs) of varying chain length are bioaccumulative in biota. However, wildlife reports have focused on liver and with very little examination of other tissues, and thus there is a limited understanding of their distribution and potential effects in the mammalian body. In the present study, the comparative accumulation of C(6) to C(15) PFCAs, C(4), C(6), C(8) and C(10) PFSAs, and select precursors were examined in the liver, blood, muscle, adipose, and brain of 20 polar bears (Ursus maritimus) from Scoresby Sound, Central East Greenland. Overall, PFSA and PFCA concentrations were highest in liver followed by blood > brain > muscle ≈ adipose. Liver and blood samples contained proportionally more of the shorter/medium chain length (C(6) to C(11)) PFCAs, whereas adipose and brain samples were dominated by longer chain (C(13) to C(15)) PFCAs. PFCAs with lower lipophilicities accumulated more in the liver, whereas the brain accumulated PFCAs with higher lipophilicities. The concentration ratios (±SE) between perfluorooctane sulfonate and its precursor perfluorooctane sulfonamide varied among tissues from 9 (±1):1 (muscle) to 36 (±7):1 (liver). PFCA and PFSA patterns in polar bears indicate that the pharmacokinetics of these compounds are to some extent tissue-specific, and are the result of several factors that may include differing protein interactions throughout the body.

  17. Interaction of multi-walled carbon nanotubes with perfluorinated sulfonic acid ionomers and surface treatment studies

    DEFF Research Database (Denmark)

    Andersen, Shuang Ma; Dhiman, Rajnish; Borghei, Maryam

    2014-01-01

    The interaction between high surface area nano-carbon catalyst supports for proton exchange membrane fuel cells (PEMFCs) and perfluorinated sulfonic acid (Nafion®) ionomer was studied 19 fluorine nuclear magnetic resonance spectroscopy (19F-NMR). The method was developed and improved for more eff....... The results will contribute to optimize electrode preparation with novel nano-carbon catalyst supports and durable catalyst for low temperature (LT) PEMFCs.......The interaction between high surface area nano-carbon catalyst supports for proton exchange membrane fuel cells (PEMFCs) and perfluorinated sulfonic acid (Nafion®) ionomer was studied 19 fluorine nuclear magnetic resonance spectroscopy (19F-NMR). The method was developed and improved for more...... efficient, user-friendly and systematic studies based on our earlier experience. In this work, multi-walled carbon nanotubes (MWCNTs) from Showa Denko® and the corresponding acid modified products were explored. The adsorption at low concentration was found to follow a Langmuir isotherm. Adsorption...

  18. In situ sulfonation of alkyl benzene self-assembled monolayers: product distribution and kinetic analysis.

    Science.gov (United States)

    Katash, Irit; Luo, Xianglin; Sukenik, Chaim N

    2008-10-07

    The sulfonation of aromatic rings held at the surface of a covalently anchored self-assembled monolayer has been analyzed in terms of the rates and isomer distribution of the sulfonation process. The observed product distributions are similar to those observed in solution, though the data obtained suggest that the reaction rate and the ortho/para product ratio depend on the length of the tether anchoring the aryl ring to the monolayer interface. It was also found that the interface becomes progressively more disordered and the observed reaction rates decrease as the reaction progresses. There is no evidence for a bias in favor of reaction at the more exposed para-position nor is there evidence for an enhanced reaction rate due to the increased disorder and/or improved wetting as the reaction proceeds. This is the first detailed study of electrophilic aromatic substitution at a monolayer interface. It introduces new approaches to the spectroscopic analysis of reactions on self-assembled monolayers and provides a new general approach to the analysis of isomeric product distribution in such a setting.

  19. A novel sulfonated poly(ether ether ketone) and cross-linked membranes for fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hongtao; Zhang, Gang; Wu, Jing; Zhao, Chengji; Zhang, Yang; Shao, Ke; Han, Miaomiao; Lin, Haidan; Zhu, Jing; Na, Hui [Alan G MacDiarmid Institute, College of Chemistry, Jilin University, Qianjin Street 2699, Changchun 130012, Jilin (China)

    2010-10-01

    A novel poly(ether ether ketone) (PEEK) containing pendant carboxyl groups has been synthesized by a nucleophilic polycondensation reaction. Sulfonated polymers (SPEEKs) with different ion exchange capacity are then obtained by post-sulfonation process. The structures of PEEK and SPEEKs are characterized by both FT-IR and {sup 1}H NMR. The properties of SPEEKs as candidates for proton exchange membranes are studied. The cross-linking reaction is performed at 140 C using poly(vinyl alcohol) (PVA) as the cross-linker. In comparison with the non-cross-linked membranes, some properties of the cross-linked membranes are significantly improved, such as water uptake, methanol resistance, mechanical and oxidative stabilities, while the proton conductivity decreases. The effect of PVA content on proton conductivity, water uptake, swelling ratio, and methanol permeability is also investigated. Among all the membranes, SPEEK-C-8 shows the highest selectivity of 50.5 x 10{sup 4} S s cm{sup -3}, which indicates that it is a suitable candidate for applications in direct methanol fuel cells. (author)

  20. Nafion {sup registered} /nitrated sulfonated poly(ether ether ketone) membranes for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Jie-Cheng; Kuo, Jen-Feng; Chen, Chuh-Yung [Department of Chemical Engineering, National Cheng-Kung University, Tainan, 70148 (China)

    2009-10-20

    Sulfonated poly(ether ether ketone)s (SPEEKs) are substituted on the main chain of the polymer by nitro groups and blended with Nafion {sup registered} to attain composite membranes. The sulfonation, nitration and blending are achieved with a simple, inexpensive process, and the blended membranes containing the nitrated SPEEKs reveal a liquid-liquid phase separation. The blended membranes have a lower water uptake compared to recast Nafion {sup registered}, and the methanol permeability is reduced significantly to 4.29 x 10{sup -7}-5.34 x 10{sup -7} cm{sup 2} s{sup -1} for various contents of nitrated SPEEK for S63N17, and 4.72 x 10{sup -7}-7.11 x 10{sup -7} cm{sup 2} s{sup -1} for S63N38, with a maximum proton conductivity of {proportional_to}0.085 S cm{sup -1}. This study examines the single-cell performance at 80 C of Nafion {sup registered} /nitrated SPEEK membranes with various contents of nitrated SPEEK and a degree of nitration of 23-25 mW cm{sup -2} for S63N17 and 24-29 mW cm{sup -2} for S63N38. Both the power density and open circuit voltage are higher than those of Nafion {sup registered} 115 and recast Nafion {sup registered}. (author)

  1. All solid supercapacitor based on polyaniline and crosslinked sulfonated poly[ether ether ketone

    Energy Technology Data Exchange (ETDEWEB)

    Sivaraman, P.; Kushwaha, R.K.; Shashidhara, K.; Hande, V.R.; Thakur, A.P. [Polymer Department, Naval Materials Research Laboratory (DRDO), Shil-Badlapur Road, Anand Nagar PO, Thane Dist., Ambernath, Maharashtra 421 506 (India); Samui, A.B., E-mail: absamui@rediffmail.co [Polymer Department, Naval Materials Research Laboratory (DRDO), Shil-Badlapur Road, Anand Nagar PO, Thane Dist., Ambernath, Maharashtra 421 506 (India); Khandpekar, M.M. [Materials Research Laboratory, Birla College, Kalyan, Thane Dist, Maharashtra 421 304 (India)

    2010-02-28

    All solid supercapacitor based on polyaniline (PANI) and crosslinked sulfonated poly[ether ether ketone] (XSPEEK,) is reported in this paper. The crosslinker used for sulfonated poly[ether ether ketone] (SPEEK) is 1,4-bis(hydroxymethyl) benzene. The XSPEEK is used as both solid electrolyte and separator membrane. Supercapacitors are fabricated using various PANI/XSPEEK weight ratios. These are characterized by cyclic voltammetry and galvanostatic charge-discharge studies. The supercapacitor with PANI/XSPEEK weight ratio 1:0.5, exhibit a specific capacitance of 480 F g{sup -1} of PANI. To the best of authors' knowledge, the value reported here is the highest for a supercapacitor based on a proton conducting solid polymer electrolyte and PANI. Detailed electrochemical impedance spectroscopy analysis is carried out. The analysis shows that the complex capacitance of the supercapacitor depends on the XSPEEK content. The time constant (t{sub 0}), derived from the imaginary part of complex capacitance decreases with increase in the XSPEEK content in the supercapacitor. Cycle life characteristics of the supercapacitor show a decrease in specific capacitance during initial cycles and get stabilized during later cycles.

  2. Synthesis and Characterization of Hydrophilic-Hydrophobic Poly(Arylene Ether Sulfone) Random and Segmented Copolymers for Membrane Applications

    Science.gov (United States)

    Nebipasagil, Ali

    Poly(arylene ether sulfone)s are high-performance engineering thermoplastics that have been investigated extensively over the past several decades due to their outstanding mechanical properties, high glass transition temperatures (Tg), solvent resistance and exceptional thermal, oxidative and hydrolytic stability. Their thermal and mechanical properties are highly suited to a variety of applications including membrane applications such as reverse osmosis, ultrafiltration, and gas separation. This dissertation covers structure-property-performance relationships of poly(arylene ether sulfone) and poly(ethylene oxide)-containing random and segmented copolymers for reverse osmosis and gas separation membranes. The second chapter of this dissertation describes synthesis of disulfonated poly(arylene ether sulfone) random copolymers with oligomeric molecular weights that contain hydrophilic and hydrophobic segments for thin film composite (TFC) reverse osmosis membranes. These copolymers were synthesized and chemically modified to obtain novel crosslinkable poly(arylene ether sulfone) oligomers with acrylamide groups on both ends. The acrylamideterminated oligomers were crosslinked with UV radiation in the presence of a multifunctional acrylate and a UV initiator. Transparent, dense films were obtained with high gel fractions. Mechanically robust TFC membranes were prepared from either aqueous or water-methanol solutions cast onto a commercial UDELRTM foam support. This was the first example that utilized a water or alcohol solvent system and UV radiation to obtain reverse osmosis TFC membranes. The membranes were characterized with regard to composition, surface properties, and water uptake. Water and salt transport properties were elucidated at the department of chemical engineering at the University of Texas at Austin. The gas separation membranes presented in chapter three were poly(arylene ether sulfone) and poly(ethylene oxide) (PEO)-containing polyurethanes. Poly

  3. Historia de las Universidades.

    Directory of Open Access Journals (Sweden)

    Jaime Escobar Triana

    1999-04-01

    ínicos”

    La civilización medieval produjo los arquetipos y el impulso dinámico para las fuerzas principales del mundo moderno. Representa el período de gestación de la cultura moderna. La ciencia occidental se desarrolló en las redes de la erudición medieval que en el siglo XII eran las escuelas catedralicias. La catedral de Chartres, simboliza, históricamente los comienzos de nuestra era científica y tecnológica.

    En la escuela de Chartres se establecieron las bases filosóficas para el surgimiento de la ciencia medieval y la moderna. El estudio de la naturaleza se constituyó en disciplina por derecho propio. En Chartres, durante el siglo XII, el estudio de la ciencia obtuvo por primera vez una prioridad definitiva sobre la enseñanza de las artes liberales y los maestros lucharon por la instauración de osadas reformas en la educación superior general centrando el programa de estudios de ciencias naturales en el cuadrivio: aritmética, música (como matemáticas geometría y astronomía y no en las humanidades tradicionales del trivio: gramática, retórica y lógica.

    La escuela de Chartres desafiaba así a los 7 siglos de enseñanzas cristianas a cerca del lugar de la naturaleza en el esquema divino, contra todas las resistencias de las grandes escuelas catedralicias de Orleans, Saint Victor en París y Laon. El ser humano y el mundo eran una unidad en el pensamiento de Chartres; trivio y cuadrivio eran parte de un universo único. Pedro Abelardo En sus escritos (siglo XII se hallan las raíces históricas de la técnica, del método con el que las grandes escuelas universitarias del S XIII construyeron, organizaron y expresaron sus doctrinas, las síntesis teológicas más complejas y más completas de la edad media. Abelardo en la Escuela de Santa Genoveva en París y Cátedra de Notre-Dame, Busca huir de los condicionamientos de las estructuras culturales cerradas e inmóviles y de las rígidas concepciones tradicionales para abrirse a una vía de investigaci

  4. Sulfonated Holey Graphene Oxide (SHGO) Filled Sulfonated Poly(ether ether ketone) Membrane: The Role of Holes in the SHGO in Improving Its Performance as Proton Exchange Membrane for Direct Methanol Fuel Cells.

    Science.gov (United States)

    Jiang, Zhong-Jie; Jiang, Zhongqing; Tian, Xiaoning; Luo, Lijuan; Liu, Meilin

    2017-06-14

    Sulfonated holey graphene oxides (SHGOs) have been synthesized by the etching of sulfonated graphene oxides with concentrated HNO 3 under the assistance of ultrasonication. These SHGOs could be used as fillers for the sulfonated aromatic poly(ether ether ketone) (SPEEK) membrane. The obtained SHGO-incorporated SPEEK membrane has a uniform and dense structure, exhibiting higher performance as proton exchange membranes (PEMs), for instance, higher proton conductivity, lower activation energy for proton conduction, and comparable methanol permeability, as compared to Nafion 112. The sulfonated graphitic structure of the SHGOs is believed to be one of the crucial factors resulting in the higher performance of the SPEEK/SHGO membrane, since it could increase the local density of the -SO 3 H groups in the membrane and induce a strong interfacial interaction between SHGO and the SPEEK matrix, which improve the proton conductivity and lower the swelling ratio of the membrane, respectively. Additionally, the proton conductivity of the membrane could be further enhanced by the presence of the holes in the graphitic planes of the SHGOs, since it provides an additional channel for transport of the protons. When used, direct methanol fuel cell with the SPEEK/SHGO membrane is found to exhibit much higher performance than that with Nafion 112, suggesting potential use of the SPEEK/SHGO membrane as the PEMs.

  5. Las organizaciones complejas

    Directory of Open Access Journals (Sweden)

    Julio Mario Rodríguez Devis

    2002-05-01

    Full Text Available El aproximarse a las organizaciones con la visión de la complejidad permite observar sus múltiples interrelaciones, la relación orden-desorden-relaciones-retroacciones que se desarrollan en su interior, la íntima influencia bi-direccional entre el entorno y la organización, la emergencia y la autoorganizacion, la importancia de la información-ruido; en fin, observar a la organización como un sistema dinámico, no lineal, abierto y complejo. En este artículo se presentan los fundamentos de la complejidad en las organizaciones, y se describen los principales elementos que la constituyen.

  6. Las declinaciones del aura

    Directory of Open Access Journals (Sweden)

    Cecilia Bettoni

    2016-11-01

    Full Text Available Habitualmente, asociamos el concepto benjaminiano de aura a una cualidad de la obra de arte que desfallece con el creciente desarrollo de las técnicas mecánicas de reproducción. Sin embargo, el mismo Benjamin señala que este desfallecimiento es un proceso sintomático, cuyo significado desborda el dominio puramente artístico. En este contexto, el presente artículo indaga este desborde a partir de la elasticidad que la noción de aura alcanza en la obra de Walter Benjamin, con el objeto de demostrar que este concepto no constituye un elemento privativo de las obras de arte, sino que se refiere más bien a cierta modulación de la experiencia histórica y estética

  7. Historia de las Hormonas

    Directory of Open Access Journals (Sweden)

    Alfredo Jácome-Roca

    2009-01-01

    Full Text Available

    El historiador Garrison afirma en su libro Introducción a la Historia de la Medicina que… “la nueva ciencia de la endocrinología, aunque arraigada en el pasado prehistórico, es virtualmente una creación del siglo XX…”

    Eso es precisamente lo que se quiere mostrar en este libro: las raíces hundidas en el pasado y los sorprendentes hallazgos de la modernidad de la centuria precedente, con algunos hechos importantes acaecidos en el siglo XIX.

    Los primeros datos conocidos comenzaron por las observaciones sobre animales y humanos castrados, sobre gigantes y enanos, diabéticos, cotudos y cretinos, y luego sobre las descripciones incipientes de los órganos endocrinos más grandes como el cuerpo tiroides, las cápsulas suprarrenales, testículos, ovarios y la glándula pituitaria. Personajes que podrían perfectamente provenir del país de Lilliput o de un circo del vecindario, tal era su extraña apariencia.

    Una eventual relación entre los casos clínicos mencionados y las glándulas se ignoraba casi totalmente, casi porque sí se sabía lo que ocurría a un animal o a un hombre castrado, antes y después de la pubertad. Por eso nos detendremos en algunas anécdotas (imposible la historia completa de los eunucos (y por espacio de dos siglos, particularmente en Italia, de los hombres-soprano denominados los castrati.

    Persistía la incógnita sobre la función de ciertos órganos o tejidos –llamados por siglos glándulas sin conducto (incluídos órganos hematopoyéticos como el timo, el bazo o los ganglios linfáticos: una pituitaria productora de moco, que drenaba en las fosas nasales el moco excesivo que se producía en los catarros; o una tiroides que lubricaba la laringe, unas cápsulas suprarrenales que sostenían los riñones, unos ovarios que eran testículos femeninos, o unos testículos que –esos sí- regaban semilla en el útero de las mujeres. Y tambi

  8. Derrida en las pampas

    Directory of Open Access Journals (Sweden)

    Analía Gerbaudo

    2011-07-01

    Full Text Available http://dx.doi.org/10.5007/1984-784X.2011v11n16p16 En el año 2003 Mariano Ben Plotkin publica Freud en las pampas. Orígenes y desarrollo de una cultura psicoanalítica en la Argentina (1910-1983: un estudio minucioso de la recepción y difusión del psicoanálisis que recupero tanto en sus aspectos metodológicos como en sus conjeturas sobre la relación que los intelectuales argentinos suelen entablar con el pensamiento europeo (tesis que se refuerzan si se las lee en conjunción con las desarrolladas respecto de lo que ha acontecido en el campo de los estudios literarios en nuestro país entre la segunda mitad del siglo XX hasta la fecha –cf. Gerbaudo, 2006a, 2007a, 2007b-. Plotkin pone la descripción de la masiva difusión del psicoanálisis en Argentina en el corte temporal seleccionado al servicio del estudio de los factores culturales, sociales y políticos que hicieron lugar a esa acogida.

  9. Las juventudes falangistas

    Directory of Open Access Journals (Sweden)

    Ricardo L. CHUECA RODRÍGUEZ

    2010-03-01

    Full Text Available RESUMEN: Una de las servidumbres de cualquier intervención como la que me propongo realizar aquí es la de los prolegómenos, siempre inevitables. Cuando inicié la preparación de estas líneas pronto caí en la cuenta de que poco se podía entender sin clarificar una serie de cuestiones que yo creía previas. Al final no resultaron ser previas sino más bien contextúales. En todo caso necesarias. Por eso en primer lugar nos detendremos en intentar desentrañar las relaciones entre juventud y fascismo. Veremos después algunos datos contextúales de Falange como partido único en el régimen de Franco, y terminaremos analizando las causas del fracaso de la organización juvenil falangista como aparato del Partido, dirigido a obtener tanto una reprodución política interna como su implantación en la sociedad civil.

  10. Familia y desarrollo profesional : las mujeres en las organizaciones educativas

    OpenAIRE

    Moreno Sánchez, Emilia

    2009-01-01

    En este artículo se reflexiona acerca de la situación laboral de la mujer en la sociedad actual. Se analizan las barreras culturales, sociales yy educativas que impiden su desarrollo profesional, en especial las relacionadas con el cuidado de la familia y del Bogar, de las profesionales de la enseñanza. En él se pone de manifiesto que son las mujeres quienes se responsabilizan del cuidado de los hijos e hijas y de las tareas domésticas, en mayor proporción que los hombres, repercu...

  11. Las Violencias contra las Mujeres en una Sociedad en Guerra

    OpenAIRE

    Sánchez Gómez, Olga Amparo

    2008-01-01

    Las violencias contra las mujeres exceden los acontecimientos violentos, y abarcan su producción y reproducción como fenómeno social y discursivo. Los hechos violentos y los discursos sobre la violencia aparecen entrelazados, especialmente si se piensa en papel que juega la cultura patriarcal en el desarrollo, perpetuación y validación de las violencias contra las mujeres. “A las mujeres nos violan, nos asaltan y nos golpean, nos ultrajan, nos humillan, nos deshumanizan, nos manosean, nos ase...

  12. Synthesis and properties of novel photosensitive poly(arylene ether sulfone) containing chalcone moiety in the main chain

    Energy Technology Data Exchange (ETDEWEB)

    Wen Pushan [Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, South-Central University for Nationalities, Wuhan 430074 (China); Wang Lei [Department of Materials Physics and Chemistry, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Zhang Aiqing [Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, South-Central University for Nationalities, Wuhan 430074 (China); Li Xiangdan, E-mail: xiangdanli@yahoo.com.cn [Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, South-Central University for Nationalities, Wuhan 430074 (China); Lee, Myong-Hoon, E-mail: mhlee2@chonbuk.ac.kr [Department of Polymer/Nano Science and Technology, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2011-04-15

    Research highlights: {yields} A series of novel photosensitive poly(arylene ether sulfone)s (PAESs) containing chalcone moiety in the main chain have been successfully synthesized. {yields} The photo-crosslinking of polymer film was carried out under UV irradiation without photoinitiator. {yields} The resulting polymers showed good thermal stability and excellent chemical stability after crosslinking. - Abstract: A new series of photosensitive poly(arylene ether sulfone)s containing chalcone moiety in the main chain were synthesized from 4,4'-dihydroxychalcone (4DHC), 4,4'-difluorodiphenylsulfone (DFDPS) and bisphenol A (BPA). This series of polymers were characterized by {sup 1}H NMR, FT-IR, UV spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The polymers were stable up to 400 deg. C, which indicates that the polymers possess good thermal properties. The polymers were found to be soluble in polar solvents and chlorinated solvents. However, the polymers were insoluble in hydrocarbons and in hydroxyl group-containing solvents. After the irradiation of UV light, the thin polymer film was crosslinked to give an insoluble film in the absence of a photoinitiator or sensitizers. The rate of photocrosslinking was also examined and discussed.

  13. Comparative study of the addition compounds between lanthanides methane sulfonates (III) and aromatic amino-oxides as ligands

    International Nuclear Information System (INIS)

    Rosario Matos, J. do.

    1989-01-01

    The main goal of this thesis is to further develop the studies on the preparation and characterization of addition compounds obtained from the reaction of lanthanide methane sulfonates and aromatic amino oxides as ligands, pyridine-N-oxides as the picoline-N-oxides (2-pic NO, 3-pic NO and 4-picNO) in order to make a comparative study. (author)

  14. Sulfonated amphiphilic block copolymers : synthesis, self-assembly in water, and application as stabilizer in emulsion polymerization

    Science.gov (United States)

    Jiguang Zhang; Matthew R. Dubay; Carl J. Houtman; Steven J. Severtson

    2009-01-01

    Described is the synthesis of diblock copolymers generated via sequential atom transfer radical polymerization (ATRP) of poly(n-butyl acrylate) (PnBA) followed by chain augmentation with either sulfonated poly(2-hydroxyethyl methacrylate) (PHEMA) or poly(2-hydroxyethyl acrylate) (PHEA) blocks. ATRP of PHEMA or PHEA from PnBA macroinitiator was conducted in acetone/...

  15. Accumulation of perfluorooctane sulfonate (PFOS) in the food chain of the Western Scheldt estuary: Comparing field measurements with kinetic modeling

    NARCIS (Netherlands)

    de Vos, M.G.; Huijbregts, M.A.J.; van den Heuvel-Greve, M.; Vethaak, A.D.; de Vijver, K.I.V.; Leonards, P.E.G.; van Leeuwen, S.P.J.; de Voogt, P.; Hendriks, A.J.

    2008-01-01

    The environmentally persistent perfluorooctane sulfonate (PFOS) is a perfluoroalkylated acid (PFA), which has been found to accumulate and biomagnify through food webs all over the world. In the present investigation, the accumulation kinetics of PFOS was explored using the bioaccumulation model

  16. Partially Fluorinated Sulfonated Poly(ether amide Fuel Cell Membranes: Influence of Chemical Structure on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Chulsung Bae

    2011-01-01

    Full Text Available A series of fluorinated sulfonated poly (ether amides (SPAs were synthesized for proton exchange membrane fuel cell applications. A polycondensation reaction of 4,4’-oxydianiline, 2-sulfoterephthalic acid monosodium salt, and tetrafluorophenylene dicarboxylic acids (terephthalic and isophthalic or fluoroaliphatic dicarboxylic acids produced SPAs with sulfonation degrees of 80–90%. Controlling the feed ratio of the sulfonated and unsulfonated dicarboxylic acid monomers afforded random SPAs with ion exchange capacities between 1.7 and 2.2 meq/g and good solubility in polar aprotic solvents. Their structures were characterized using NMR and FT IR spectroscopies. Tough, flexible, and transparent films were obtained with dimethylsulfoxide using a solution casting method. Most SPA membranes with 90% sulfonation degree showed high proton conductivity (>100 mS/cm at 80 °C and 100% relative humidity. Among them, two outstanding ionomers (ODA-STA-TPA-90 and ODA-STA-IPA-90 showed proton conductivity comparable to that of Nafion 117 between 40 and 80 °C. The influence of chemical structure on the membrane properties was systematically investigated by comparing the fluorinated polymers to their hydrogenated counterparts. The results suggest that the incorporation of fluorinated moieties in the polymer backbone of the membrane reduces water absorption. High molecular weight and the resulting physical entanglement of the polymers chains played a more important role in improving stability in water, however.

  17. A diastereoselective unique route to cyclopropanes functionalized at all three ring carbon atoms from acyclic vinyl sulfone-modified carbohydrates.

    Science.gov (United States)

    Atta, Ananta Kumar; Pathak, Tanmaya

    2009-04-03

    In a departure from the current trend of using metal-catalyzed routes to cyclopropanation, pentosyl and hexosyl vinyl sulfone-modified carbohydrates having the terminal double bond and a suitably positioned leaving group are reacted in a stereoselective fashion with a series of nucleophiles to yield a myriad of cyclopropanes substituted at all three ring carbon atoms.

  18. Estimated pKa values for the environmentally relevant C1 through C8 perfluorinated sulfonic acid isomers.

    Science.gov (United States)

    Rayne, Sierra; Forest, Kaya

    2016-10-14

    In order to estimate isomer-specific acidity constants (pKa) for the perfluorinated sulfonic acid (PFSA) environmental contaminants, the parameterization method 6 (PM6) pKa prediction method was extensively validated against a wide range of carbon oxyacids and related sulfonic/sulfinic acids. Excellent pKa prediction performance was observed for the carbon oxyacids using the PM6 method, but this approach was found to have a severe positive bias for sulfonic/sulfinic acids. To overcome this obstacle, a correlation was developed between non-adjusted PM6 pKa values and the corresponding experimentally obtained/estimated acidity constants for a range of representative alkyl, aryl and halogen-substituted sulfonic acids. Application of this correction to the PM6 values allows for extension of this computational method to a new acid functional group. When used to estimate isomer-specific pKa values for the C1 through C8 PFSAs, the modified PM6 approach suggests an adjusted pKa range from -5.3 to -9.0, indicating that all members of this class of well-known environmental contaminants will be effectively completely dissociated in aquatic systems.

  19. Ion-Selective Ionic Polymer Metal Composite (IPMC) Actuator Based on Crown Ether Containing Sulfonated Poly(Arylene Ether Ketone)

    NARCIS (Netherlands)

    Tas, Sinem; Zoetebier, Bram; Sardan Sukas, Ö.; Bayraktar, Muharrem; Hempenius, Mark A.; Vancso, Gyula J.; Nijmeijer, Dorothea C.

    This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane

  20. Sulfonic acid-functionalized golf nanoparticles: A colloid-bound catalyst for soft lithographic application on self-assembled monolayers

    NARCIS (Netherlands)

    Li, X.; Paraschiv, V.; Huskens, Jurriaan; Reinhoudt, David

    2003-01-01

    In this report, we present a new lithographic approach to prepare patterned surfaces. Self-assembled monolayers (SAMs) of the acid-labile trimethylsilyl ether (TMS-OC11H22S)2 (TMS adsorbate) was formed on gold. 5-Mercapto-2-benzimidazole sulfonic acid sodium salt (MBS-Na+) was used as a ligand for