The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Ho Kyong Shon - One of the best experts on this subject based on the ideXlab platform.
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effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane
Desalination, 2016Co-Authors: Soleyman Sahebi, Sherub Phuntsho, Myoung Jun Park, Leonard D Tijing, Seungkwan Hong, Ho Kyong ShonAbstract:Abstract Sulphonated polyethersulfone (SPES) has been synthesized for developing high performance thin film composite (TFC) forward osmosis (FO) membranes with enhanced hydrophilic support layer. Sulphonated substrate not only affects the membrane performance but also changes the membrane morphology from finger-like structure to a sponge-like morphology at higher degree of Sulphonation thereby affecting the mechanical strength of the FO membrane. Non-sulphonated TFC-FO membrane with 12 wt.% polymer concentration shows a faint finger-like structure while sulphonated samples at a similar polymer concentration show a fully sponge-like structure with a much higher performance. For example, a water flux of 35 Lm− 2 h− 1 and 0.28 g L− 1 specific reverse solute flux was achieved with sulphonated TFC-FO membrane sample (50 wt.% SPES) under the FO mode using 2 M NaCl as the draw solution and deionized water as feed. Substrate Sulphonation also considerably decreased the membrane structural parameter from 1096 μm without Sulphonation to 245 μm at 50 wt.% Sulphonation. This study therefore shows that, besides surface morphology, the water flux of the FO membrane can also be enhanced by improving its substrate hydrophilic property.
Soleyman Sahebi - One of the best experts on this subject based on the ideXlab platform.
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effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane
Desalination, 2016Co-Authors: Soleyman Sahebi, Sherub Phuntsho, Myoung Jun Park, Leonard D Tijing, Seungkwan Hong, Ho Kyong ShonAbstract:Abstract Sulphonated polyethersulfone (SPES) has been synthesized for developing high performance thin film composite (TFC) forward osmosis (FO) membranes with enhanced hydrophilic support layer. Sulphonated substrate not only affects the membrane performance but also changes the membrane morphology from finger-like structure to a sponge-like morphology at higher degree of Sulphonation thereby affecting the mechanical strength of the FO membrane. Non-sulphonated TFC-FO membrane with 12 wt.% polymer concentration shows a faint finger-like structure while sulphonated samples at a similar polymer concentration show a fully sponge-like structure with a much higher performance. For example, a water flux of 35 Lm− 2 h− 1 and 0.28 g L− 1 specific reverse solute flux was achieved with sulphonated TFC-FO membrane sample (50 wt.% SPES) under the FO mode using 2 M NaCl as the draw solution and deionized water as feed. Substrate Sulphonation also considerably decreased the membrane structural parameter from 1096 μm without Sulphonation to 245 μm at 50 wt.% Sulphonation. This study therefore shows that, besides surface morphology, the water flux of the FO membrane can also be enhanced by improving its substrate hydrophilic property.
Hans Cerfontain - One of the best experts on this subject based on the ideXlab platform.
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Aromatic Sulphonation IXheterogeneous Sulphonation of toluene with aqueous sulphuric acid
Recueil des Travaux Chimiques des Pays-Bas, 2010Co-Authors: Hans Cerfontain, F. L. J. Sixma, L. VollbrachtAbstract:The heterogeneous Sulphonation of toluene with 81.9 and 95.9 wt-% aqueous sulphuric acid has been studied at 25°. The isomer distribution which deviates from that observed in homogeneous Sulphonation, varies with toluene conversion and with toluene to sulphuric acid volume ratio. The content of p-toluenesulphonic acid is higher under heterogeneous conditions than under homogeneous conditions. It is suggested that the variation in isomer distribution is due chiefly to the presence of increasing amounts of sulphonic acids in the sulphuric acid phase. The heterogeneous Sulphonation of toluene proceeds mainly in the sulphuric acid phase. Some Sulphonation in the toluene phase by sulphur trioxide may take place as well. However, the latter process is of little - if any - importance.
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Aromatic Sulphonation III: Sulphonation of benzenesulphonic acid and m‐toluenesulphonic acid in fuming sulphuric acid
Recueil des Travaux Chimiques des Pays-Bas, 2010Co-Authors: Hans CerfontainAbstract:The kinetics of the Sulphonation of benzenesulphonic acid and m-toluenesulphonic acid have been measured in oleum, containing 0.7 to 43.6% of sulphur trioxide 1 at 25°. The reaction is first order with respect to the sulphonic acid. The kinetics are shown to be consistent with the Sulphonation mechanism proposed by Brand1, in which the reaction proceeds by a stepwise attachment of SO3 and H+ to the substrate, followed by the loss of a proton from the benzene ring. Sulphonation of the protonated sulphonic acid cannot be ruled out. Its contribution to the total rate of Sulphonation is regarded as small in view of its electrophilic nature.
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aromatic Sulphonation iii Sulphonation of benzenesulphonic acid and m toluenesulphonic acid in fuming sulphuric acid
Recueil des Travaux Chimiques des Pays-Bas, 2010Co-Authors: Hans CerfontainAbstract:The kinetics of the Sulphonation of benzenesulphonic acid and m-toluenesulphonic acid have been measured in oleum, containing 0.7 to 43.6% of sulphur trioxide 1 at 25°. The reaction is first order with respect to the sulphonic acid. The kinetics are shown to be consistent with the Sulphonation mechanism proposed by Brand1, in which the reaction proceeds by a stepwise attachment of SO3 and H+ to the substrate, followed by the loss of a proton from the benzene ring. Sulphonation of the protonated sulphonic acid cannot be ruled out. Its contribution to the total rate of Sulphonation is regarded as small in view of its electrophilic nature.
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Aromatic Sulphonation V: A kinetic study on the Sulphonation of toluene, ethylbenzene and isopropylbenzene in aqueous sulphuric acid
Recueil des Travaux Chimiques des Pays-Bas, 2010Co-Authors: A. W. Kaandorp, Hans Cerfontain, F. L. J. SixmaAbstract:Rate measurements have been made on the homogeneous Sulphonation of toluene in aqueous sulphuric acid varying from 70.0 to 95.9 wt-% at 5.0°, 25.0° and 45.0°. In addition, rate constants have been determined for the homogeneous Sulphonation of ethylbenzene and isopropylbenzene at 25.0° in aqueous sulphuric acid solutions varying from 72.4 to 89.1 wt-%. All reactions were found to be first order with respect to the aromatic compound. It is suggested that the differences in the overall rate constants for the Sulphonation of toluene, ethylbenzene and isopropylbenzene originate predominantly from steric hindrance for ortho-substitution.
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aromatic Sulphonation iv kinetics and mechanism of the Sulphonation of benzene in aqueous sulphuric acid
Recueil des Travaux Chimiques des Pays-Bas, 2010Co-Authors: A. W. Kaandorp, Hans Cerfontain, F. L. J. SixmaAbstract:The kinetics of the Sulphonation of benzene have been measured at 5.0°, 25.0° and 45.0° in aqueous sulphuric acid solutions, varying from 77.6 to 99.2 wt-% H2SO4In addition, Sulphonation rate measurements have been made at 5.0° in 98.8 wt-% H2SO4containing various concentrations of sodium bisulphate. All reactions were found to be first order with respect to benzene. The kinetics are discussed in terms of the mechanism: It is suggested that sulphur trioxide or, though less probable, the sulphuric acid solvate of sulphur trioxide SO3(H2SO4) or disulphuric acid (H2S2O7), is the sulphonating entity X and thatk1
Leonard D Tijing - One of the best experts on this subject based on the ideXlab platform.
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effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane
Desalination, 2016Co-Authors: Soleyman Sahebi, Sherub Phuntsho, Myoung Jun Park, Leonard D Tijing, Seungkwan Hong, Ho Kyong ShonAbstract:Abstract Sulphonated polyethersulfone (SPES) has been synthesized for developing high performance thin film composite (TFC) forward osmosis (FO) membranes with enhanced hydrophilic support layer. Sulphonated substrate not only affects the membrane performance but also changes the membrane morphology from finger-like structure to a sponge-like morphology at higher degree of Sulphonation thereby affecting the mechanical strength of the FO membrane. Non-sulphonated TFC-FO membrane with 12 wt.% polymer concentration shows a faint finger-like structure while sulphonated samples at a similar polymer concentration show a fully sponge-like structure with a much higher performance. For example, a water flux of 35 Lm− 2 h− 1 and 0.28 g L− 1 specific reverse solute flux was achieved with sulphonated TFC-FO membrane sample (50 wt.% SPES) under the FO mode using 2 M NaCl as the draw solution and deionized water as feed. Substrate Sulphonation also considerably decreased the membrane structural parameter from 1096 μm without Sulphonation to 245 μm at 50 wt.% Sulphonation. This study therefore shows that, besides surface morphology, the water flux of the FO membrane can also be enhanced by improving its substrate hydrophilic property.
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Effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane
'Elsevier BV', 2016Co-Authors: Sahebi S, Leonard D Tijing, Phuntsho S, Yc Woo, Mj Park, Hong S, Hk ShonAbstract:© 2015 Elsevier B.V. Sulphonated polyethersulfone (SPES) has been synthesized for developing high performance thin film composite (TFC) forward osmosis (FO) membranes with enhanced hydrophilic support layer. Sulphonated substrate not only affects the membrane performance but also changes the membrane morphology from finger-like structure to a sponge-like morphology at higher degree of Sulphonation thereby affecting the mechanical strength of the FO membrane. Non-sulphonated TFC-FO membrane with 12 wt.% polymer concentration shows a faint finger-like structure while sulphonated samples at a similar polymer concentration show a fully sponge-like structure with a much higher performance. For example, a water flux of 35 Lm-2 h-1 and 0.28 g L-1 specific reverse solute flux was achieved with sulphonated TFC-FO membrane sample (50 wt.% SPES) under the FO mode using 2 M NaCl as the draw solution and deionized water as feed. Substrate Sulphonation also considerably decreased the membrane structural parameter from 1096 μm without Sulphonation to 245 μm at 50 wt.% Sulphonation. This study therefore shows that, besides surface morphology, the water flux of the FO membrane can also be enhanced by improving its substrate hydrophilic property
Sherub Phuntsho - One of the best experts on this subject based on the ideXlab platform.
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effect of sulphonated polyethersulfone substrate for thin film composite forward osmosis membrane
Desalination, 2016Co-Authors: Soleyman Sahebi, Sherub Phuntsho, Myoung Jun Park, Leonard D Tijing, Seungkwan Hong, Ho Kyong ShonAbstract:Abstract Sulphonated polyethersulfone (SPES) has been synthesized for developing high performance thin film composite (TFC) forward osmosis (FO) membranes with enhanced hydrophilic support layer. Sulphonated substrate not only affects the membrane performance but also changes the membrane morphology from finger-like structure to a sponge-like morphology at higher degree of Sulphonation thereby affecting the mechanical strength of the FO membrane. Non-sulphonated TFC-FO membrane with 12 wt.% polymer concentration shows a faint finger-like structure while sulphonated samples at a similar polymer concentration show a fully sponge-like structure with a much higher performance. For example, a water flux of 35 Lm− 2 h− 1 and 0.28 g L− 1 specific reverse solute flux was achieved with sulphonated TFC-FO membrane sample (50 wt.% SPES) under the FO mode using 2 M NaCl as the draw solution and deionized water as feed. Substrate Sulphonation also considerably decreased the membrane structural parameter from 1096 μm without Sulphonation to 245 μm at 50 wt.% Sulphonation. This study therefore shows that, besides surface morphology, the water flux of the FO membrane can also be enhanced by improving its substrate hydrophilic property.
