A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexi...A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexistence theory and verified in four kinds of binary aqueous solutions and two kinds of ternary aqueous solutions. The calculated mass action concentrations of structural units or ion couples in four binary aqueous solutions and two ternary solutions at 298.15 K have good agreement with the reported activity data from literatures after shifting the standard state and concentration unit. Therefore, the calculated mass action concentrations of structural units or ion couples from the developed universal thermodynamic model for ternary and binary aqueous solutions can be applied to predict reaction ability of components in ternary and binary strong electrolyte aqueous solutions. It is also proved that the assumptions applied in the developed thermodynamic model are correct and reasonable, i.e., strong electrolyte aqueous solution is composed of cations and anions as simple ions, H2O as simple molecule and other hydrous salt compounds as complex molecules. The calculated mass action concentrations of structural units or ion couples in ternary and binary strong electrolyte aqueous solutions strictly follow the mass action law.展开更多
The watermiscible room temperature ionic liquid 1butyl3methylimidazolium tetrafluorob orate ([bmim] [BF4]) is a model system for studying the interactions between ionic liquid and water molecules. In this work the o...The watermiscible room temperature ionic liquid 1butyl3methylimidazolium tetrafluorob orate ([bmim] [BF4]) is a model system for studying the interactions between ionic liquid and water molecules. In this work the orientational structure of the low concentrated aqueous solution of [bmim] [BF4] at the air/liquid interface was investigated by sum frequency gener ation vibrational spectroscopy. It has been found that at very low concentrations, the butyl chain exhibited a significant gauche defect, indicating a disordered conformation; and the cation ring oriented with a fairly small tilting angle at the surface. When the concentration increased, the cation ring tended to lie flat at the surface, and the gauche defects of the butyl chain decreased due to the intermolecular chainchain interactions and the consequent more ordered interfacial molecular arrangement. Additionally, the antisymmetric stretching mode in the PPP and SPS spectra exhibited a peak shift, showing that there exists more than one kind of orientation or chemical environment for the butyl CH3 group. These results may shed new light on understanding the surface behavior of watermiscible ionic liquids as well as the imidazolium based surfactants.展开更多
Molecular interactions of the ternary mixtures of 1-butyl-3-methylimidazolium chloride ([C4C1im]Cl)-water-2,6-dimethoxyphenol (2,6-DMP, a phenolic monomer lignin model compound) were investigated in comparison wit...Molecular interactions of the ternary mixtures of 1-butyl-3-methylimidazolium chloride ([C4C1im]Cl)-water-2,6-dimethoxyphenol (2,6-DMP, a phenolic monomer lignin model compound) were investigated in comparison with the [C4C1im]Cl-water binary systems through attenuated total reflection infrared spectroscopy. Results indicated that the microstructures of water and [C4C1im]Cl changed with varying mole fraction of [C4C1im]Cl (xIL) from 0.01 to 1.0. This change was mainly attributed to the interactions of [C4C1im]Cl-water and the self-aggregation of [C4C1im]Cl through hydrogen bonding. The band shifts of C-H on imidazolium ring and the functional groups in 2,6-DMP indicated that the occurrence of intermolecular interactions by different mechanisms (i.e., hydrogen bonding or π-π stacking) resulted in 2,6-DMP dissolution. In the case of xIL=0.12, the slightly hydrogen-bonded water was fully destroyed and [C4C1im]Cl existed in the form of hydrated ion pairs. Interestingly, the maximum 2,6-DMP solubility (238.5 g/100 g) was achieved in this case. The interactions and microstructures of [C4C1im]Cl-water mixtures influenced the dissolution behavior of 2,6-DMP.展开更多
Various conditions were investigated in detail for the novel organic template-free static hydrothermal synthesis of SUZ-4 zeolite in the presence of seeds. The obtained samples were characterized by XRD (X-ray diffra...Various conditions were investigated in detail for the novel organic template-free static hydrothermal synthesis of SUZ-4 zeolite in the presence of seeds. The obtained samples were characterized by XRD (X-ray diffraction), SEM (scanning electron microscope), TG (thermal gravimetric analysis), ICP (inductively coupling plasma) elemental analysis, nitrogen sorption isotherm and surface area. The results show that pure SUZ-4 zeolites with high crystallinity are obtained in a broad window of synthesis conditions: seed mass concentration 0.2%-2%, SIO2/A1203 molar ratio 21 25, KOH/SiO2 molar ratio 0.33 0.43, H20/SiO2 molar ratio 7.14-38.1, aging time 24 h, crystallization temperature 160℃, and crystallization time 6-10 d. Also, crystallinity and size of the rod-like SUZ-4 zeolite crystals are found to alter with the conditions.展开更多
To analyze the water swelling characteristics of black cotton soil(BCS),X-ray fluorescence and X-ray diffraction characterizations were performed to investigate the chemical compositions and types of clay minerals in ...To analyze the water swelling characteristics of black cotton soil(BCS),X-ray fluorescence and X-ray diffraction characterizations were performed to investigate the chemical compositions and types of clay minerals in BCS.A montmorillonite crystal lattice was established to simulate the hydration of interlayer cations by applying the SPC/E potential energy model,universal force field,algorithm of charge balance,and periodic boundary.Results indicated that the main clay mineral found in the BCS was montmorillonite(32.6%)with small amounts of interstratified illite-montmorillonite(10.9%),illite(2.3%),and kaolinite(1.5%).The high expansive potential of BCS comes from the strong adsorption property of montmorillonite with a high content of magnesium and sodium ions to water molecules.The exchangeable cations of Na^(+)in BCS were only 3.73%,but they enhanced the adsorption capacity of clay to water molecules and accelerated the hydration of Mg^(2+)(47.1%)and Ca^(2+)(4.78%).The free swell index can be used as a classification index of the swelling potential of BCS.展开更多
In this study, the feasibility of using chitosan, a multifunctional environmentally friendly biopolymer, at different molecular weights to simultaneously adsorb various metal ions from aqueous solutions was evaluated....In this study, the feasibility of using chitosan, a multifunctional environmentally friendly biopolymer, at different molecular weights to simultaneously adsorb various metal ions from aqueous solutions was evaluated. The experiments were carried out to estimate adsorptivity and selectivity of three molecular weights chitosan, 3.60 × 105 (Chl), 5.97 × 105 (Ch2) and 9.47 × 105 (Ch3) g/mol, towards Cu(II), Ni(II), and Pb(II) ions in aqueous solutions. Experimental results indicated that chitosan of high molecular weight (Ch3) was the best at adsorption capacity than the others. On chitosan solutions followed by Ni(II) and then Cu(II). the other hand, Pb(lI) had the highest adsorption ability in the three展开更多
OBJECTIVE:To examine the antioxidative and hepatoprotective activities of the effective fraction separated from the fruit of Livistona chinensis(FLC)and to explore the possible mechanism.METHODS:The antioxidative acti...OBJECTIVE:To examine the antioxidative and hepatoprotective activities of the effective fraction separated from the fruit of Livistona chinensis(FLC)and to explore the possible mechanism.METHODS:The antioxidative activities of the various fractions separated from FLC were analyzed by in vitro DPPH(1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl,DPPH) radical and superoxide anion free radical(O^(2-)) scavenging assays.The potential hepatoprotective effects of the ethyl acetate fraction separated from FLC(EFLC) were examined in LO_2 cells and mice.LO_2 cells were incubated with EFLC and exposed to H_2O_2-induced oxidative stress.BABL/C mice were orally administered EFLC for consecutive7 d,and fulminant hepatitis was induced by cauda vein injection of Con A on day 7.RESULTS:EFLC showed prominent antioxidative effects in DPPH-and O^(2-) scavenging assays.EFLC pretreatment effectively protected LO_2 cells from H_2O_2-induced oxidative stress by decreasing apoptosis and raising the levels of antioxidant enzymes.Additionally,EFLC protected mice against Con A-induced fulminant hepatitis by markedly reducing the serum levels of alanine transaminase and aspartate aminotransferase,attenuating histological damage of the mouse liver,and elevating the levels of glutathione peroxidase and total superoxide dismutase,while decreasing the contents of methane dicarboxylic aldehyde,tumor necrosis factor-α,and interleukin-1β in the mouse liver.Furthermore,EFLC pretreatment downregulated the protein expression of B-cell lymphoma 2(Bcl-2) associated X protein,caspase-3,caspase-8,Fas,and Fas L,while upregulating the protein expression of Bcl-2 in the mouse liver.CONCLUSION:These findings revealed that EFLC effectively protected against in vivo and in vitro liver injury,and the mechanism is closely associated with its antioxidative and anti-apoptotic properties.展开更多
基金Project supported by Publication Foundation of National Science and Technology Academic Books of China
文摘A universal thermodynamic model of calculating mass action concentrations for structural units or ion couples in ternary and binary strong electrolyte aqueous solution was developed based on the ion and molecule coexistence theory and verified in four kinds of binary aqueous solutions and two kinds of ternary aqueous solutions. The calculated mass action concentrations of structural units or ion couples in four binary aqueous solutions and two ternary solutions at 298.15 K have good agreement with the reported activity data from literatures after shifting the standard state and concentration unit. Therefore, the calculated mass action concentrations of structural units or ion couples from the developed universal thermodynamic model for ternary and binary aqueous solutions can be applied to predict reaction ability of components in ternary and binary strong electrolyte aqueous solutions. It is also proved that the assumptions applied in the developed thermodynamic model are correct and reasonable, i.e., strong electrolyte aqueous solution is composed of cations and anions as simple ions, H2O as simple molecule and other hydrous salt compounds as complex molecules. The calculated mass action concentrations of structural units or ion couples in ternary and binary strong electrolyte aqueous solutions strictly follow the mass action law.
文摘The watermiscible room temperature ionic liquid 1butyl3methylimidazolium tetrafluorob orate ([bmim] [BF4]) is a model system for studying the interactions between ionic liquid and water molecules. In this work the orientational structure of the low concentrated aqueous solution of [bmim] [BF4] at the air/liquid interface was investigated by sum frequency gener ation vibrational spectroscopy. It has been found that at very low concentrations, the butyl chain exhibited a significant gauche defect, indicating a disordered conformation; and the cation ring oriented with a fairly small tilting angle at the surface. When the concentration increased, the cation ring tended to lie flat at the surface, and the gauche defects of the butyl chain decreased due to the intermolecular chainchain interactions and the consequent more ordered interfacial molecular arrangement. Additionally, the antisymmetric stretching mode in the PPP and SPS spectra exhibited a peak shift, showing that there exists more than one kind of orientation or chemical environment for the butyl CH3 group. These results may shed new light on understanding the surface behavior of watermiscible ionic liquids as well as the imidazolium based surfactants.
基金This work was supported by the National Natural Science Foundation of China (No.21106011 and No.21276034) and the Program of Science and Technology of Liaoning Province (No.201602058), and China Scholarship Council.
文摘Molecular interactions of the ternary mixtures of 1-butyl-3-methylimidazolium chloride ([C4C1im]Cl)-water-2,6-dimethoxyphenol (2,6-DMP, a phenolic monomer lignin model compound) were investigated in comparison with the [C4C1im]Cl-water binary systems through attenuated total reflection infrared spectroscopy. Results indicated that the microstructures of water and [C4C1im]Cl changed with varying mole fraction of [C4C1im]Cl (xIL) from 0.01 to 1.0. This change was mainly attributed to the interactions of [C4C1im]Cl-water and the self-aggregation of [C4C1im]Cl through hydrogen bonding. The band shifts of C-H on imidazolium ring and the functional groups in 2,6-DMP indicated that the occurrence of intermolecular interactions by different mechanisms (i.e., hydrogen bonding or π-π stacking) resulted in 2,6-DMP dissolution. In the case of xIL=0.12, the slightly hydrogen-bonded water was fully destroyed and [C4C1im]Cl existed in the form of hydrated ion pairs. Interestingly, the maximum 2,6-DMP solubility (238.5 g/100 g) was achieved in this case. The interactions and microstructures of [C4C1im]Cl-water mixtures influenced the dissolution behavior of 2,6-DMP.
基金Supported by the National Natural Science Foundation of China(20976084,21101094,21136005)
文摘Various conditions were investigated in detail for the novel organic template-free static hydrothermal synthesis of SUZ-4 zeolite in the presence of seeds. The obtained samples were characterized by XRD (X-ray diffraction), SEM (scanning electron microscope), TG (thermal gravimetric analysis), ICP (inductively coupling plasma) elemental analysis, nitrogen sorption isotherm and surface area. The results show that pure SUZ-4 zeolites with high crystallinity are obtained in a broad window of synthesis conditions: seed mass concentration 0.2%-2%, SIO2/A1203 molar ratio 21 25, KOH/SiO2 molar ratio 0.33 0.43, H20/SiO2 molar ratio 7.14-38.1, aging time 24 h, crystallization temperature 160℃, and crystallization time 6-10 d. Also, crystallinity and size of the rod-like SUZ-4 zeolite crystals are found to alter with the conditions.
基金The National Natural Science Foundation of China(No.51778139)Jiangsu Planned Projects for Postdoctoral Research Funds(No.2020Z422).
文摘To analyze the water swelling characteristics of black cotton soil(BCS),X-ray fluorescence and X-ray diffraction characterizations were performed to investigate the chemical compositions and types of clay minerals in BCS.A montmorillonite crystal lattice was established to simulate the hydration of interlayer cations by applying the SPC/E potential energy model,universal force field,algorithm of charge balance,and periodic boundary.Results indicated that the main clay mineral found in the BCS was montmorillonite(32.6%)with small amounts of interstratified illite-montmorillonite(10.9%),illite(2.3%),and kaolinite(1.5%).The high expansive potential of BCS comes from the strong adsorption property of montmorillonite with a high content of magnesium and sodium ions to water molecules.The exchangeable cations of Na^(+)in BCS were only 3.73%,but they enhanced the adsorption capacity of clay to water molecules and accelerated the hydration of Mg^(2+)(47.1%)and Ca^(2+)(4.78%).The free swell index can be used as a classification index of the swelling potential of BCS.
文摘In this study, the feasibility of using chitosan, a multifunctional environmentally friendly biopolymer, at different molecular weights to simultaneously adsorb various metal ions from aqueous solutions was evaluated. The experiments were carried out to estimate adsorptivity and selectivity of three molecular weights chitosan, 3.60 × 105 (Chl), 5.97 × 105 (Ch2) and 9.47 × 105 (Ch3) g/mol, towards Cu(II), Ni(II), and Pb(II) ions in aqueous solutions. Experimental results indicated that chitosan of high molecular weight (Ch3) was the best at adsorption capacity than the others. On chitosan solutions followed by Ni(II) and then Cu(II). the other hand, Pb(lI) had the highest adsorption ability in the three
基金the Science and Technology Plan Projects of Guangdong(No.2013A022100002)
文摘OBJECTIVE:To examine the antioxidative and hepatoprotective activities of the effective fraction separated from the fruit of Livistona chinensis(FLC)and to explore the possible mechanism.METHODS:The antioxidative activities of the various fractions separated from FLC were analyzed by in vitro DPPH(1,1-diphenyl-2-picrylhydrazyl radical 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl,DPPH) radical and superoxide anion free radical(O^(2-)) scavenging assays.The potential hepatoprotective effects of the ethyl acetate fraction separated from FLC(EFLC) were examined in LO_2 cells and mice.LO_2 cells were incubated with EFLC and exposed to H_2O_2-induced oxidative stress.BABL/C mice were orally administered EFLC for consecutive7 d,and fulminant hepatitis was induced by cauda vein injection of Con A on day 7.RESULTS:EFLC showed prominent antioxidative effects in DPPH-and O^(2-) scavenging assays.EFLC pretreatment effectively protected LO_2 cells from H_2O_2-induced oxidative stress by decreasing apoptosis and raising the levels of antioxidant enzymes.Additionally,EFLC protected mice against Con A-induced fulminant hepatitis by markedly reducing the serum levels of alanine transaminase and aspartate aminotransferase,attenuating histological damage of the mouse liver,and elevating the levels of glutathione peroxidase and total superoxide dismutase,while decreasing the contents of methane dicarboxylic aldehyde,tumor necrosis factor-α,and interleukin-1β in the mouse liver.Furthermore,EFLC pretreatment downregulated the protein expression of B-cell lymphoma 2(Bcl-2) associated X protein,caspase-3,caspase-8,Fas,and Fas L,while upregulating the protein expression of Bcl-2 in the mouse liver.CONCLUSION:These findings revealed that EFLC effectively protected against in vivo and in vitro liver injury,and the mechanism is closely associated with its antioxidative and anti-apoptotic properties.