Hofmeister series ranks the ability of salt ions in influencing a variety of properties and processes in aqueous solutions.In this review,we reexamine how these ions and some other small molecules affect water structu...Hofmeister series ranks the ability of salt ions in influencing a variety of properties and processes in aqueous solutions.In this review,we reexamine how these ions and some other small molecules affect water structure and thermodynamic properties,such as surface tension and protein backbone solvation.We illustrate the difficulties in interpreting the thermodynamic information based on structural and dynamic arguments.As an alternative,we show that the solvation properties of ions and proteins/small molecules can be used to explain the salt effects on the thermodynamic properties of the solutions.Our analysis shows that the often neglected cation-anion cooperativity plays a very important role in these effects.We also argue that the change of hydrogen donor/acceptor equilibrium by added cosolutes/cosolvents can be used to explain their effects on protein secondary structure denaturation/protection:those increase hydrogen donor concentrations such as urea and salts with strongly solvated cations/weakly hydrated anions tend to dissolve protein backbone acting as secondary structure denaturants,whereas those lack of hydrogen donors but rich in acceptors have the opposite effect.展开更多
The solvation of carbon dioxide in sea water plays an important role in the carbon circle and the world climate. The salting-out/salting-in mechanism of CO2 in electrolyte solutions still remains elusive at molecule l...The solvation of carbon dioxide in sea water plays an important role in the carbon circle and the world climate. The salting-out/salting-in mechanism of CO2 in electrolyte solutions still remains elusive at molecule level. The ability of ion salting-out/salting-in CO2 in electrolyte solution follows Hofmeister Series and the change of water mobility induced by salts can be predicted by the viscosity B-coefficients. In this work, the chemical potential of carbon dioxide and the dynamic properties of water in aqueous NaCl, KF and NaClO4 solutions are calculated and analyzed. According to the viscosity B-coefficients, NaClO4 （0.012） should salt out the carbon dioxide relative to in pure water, but the opposite effect is observed for it. Our simulation results suggest that the salting-in effect of NaClO4 is due to the strongly direct anion-CO2 interaction. The inconsistency between＂ Hofmeister Series and the viscosity B-coefficient suggests that it is not always right to indicate whether a salt belongs to salting-in or salting-out just from these properties of the salt solution in the absence of solute.展开更多
The effect of electrolytes on the micellar behavior of an amphiphilic drug, chlorpromazine (CPZ) hydrochloride, was studied using cloud point (CP) and dye solubilization techniques. In the presence of KBr, increase in...The effect of electrolytes on the micellar behavior of an amphiphilic drug, chlorpromazine (CPZ) hydrochloride, was studied using cloud point (CP) and dye solubilization techniques. In the presence of KBr, increase in pH led to decrease in the CP of 50 mmol·L-1 drug solution (prepared in 10 mmol·L-1 sodium phosphate (SP) buffer) because of deprotonation of drug molecules at high pH. The visible absorbance increased (due to dye solubilization) with the increase in pH from 6.5 to 6.9, which indicated micellar growth. At fixed pH (6.7), addition of inorganic salts (KF, KCl, and KBr) to drug solutions (50 mmol·L-1) caused an increase in the CP as well as in the visible absorbance, with effectiveness being in the order: F-<Cl-<Br-. The results were discussed on the basis of counter-ion binding and their effect toward micellar growth. Cations (co-ions) also led to an increase in the CP (and also the visible absorbance), with their effectiveness order being Li+ >Na+ >K+, which was explained by considering cognizance of their hydrated radii. Compared with anions, their effect was small. Increase in [CPZ] caused micellar growth and hence the CP as well as the visible absorbance increased. The overall behavior was discussed in terms of electrostatic interactions and micellar growth.展开更多
Zeolites are of great industrial relevance as catalysts,adsorbents,and ion-exchangers and typically synthesized under hydrothermal conditions.Rational regulation of their crystallization process is of great significan...Zeolites are of great industrial relevance as catalysts,adsorbents,and ion-exchangers and typically synthesized under hydrothermal conditions.Rational regulation of their crystallization process is of great significance for zeolite production.In this work,we systematically investigate the role of anions in tuning zeolite crystallization via anion introduction including SO_(4)^(2−),F^(−),Cl^(−),Br^(−),I^(−),and SCN^(−) in the sodium form into the SiO2-TPAOH-H2O[tetrapropylammonium hydroxide(TPAOH)]synthetic system of silicalite-1 zeolite.展开更多
An un precedented tun able hydrophobic effect in self-assembly of a small cationic organic fluorophore(NI-TPy^(+))-based with aggregation-induced emission(AIE)property was realized in aqueous solution.The amplificatio...An un precedented tun able hydrophobic effect in self-assembly of a small cationic organic fluorophore(NI-TPy^(+))-based with aggregation-induced emission(AIE)property was realized in aqueous solution.The amplification of hydrophobicity was found to be significantly dependent upon the increasing aggregates of NI-TPy^(+),which enabled the study of the hydrophobic binding of chaotropic anions with the Hofmeister series.展开更多
基金National Fund for Fostering Talents of Basic Sciences(J0630421)the National Natural Science Foundation of China(21125311)the National Basic Research Program of China(2012CB917304)for financial support
文摘Hofmeister series ranks the ability of salt ions in influencing a variety of properties and processes in aqueous solutions.In this review,we reexamine how these ions and some other small molecules affect water structure and thermodynamic properties,such as surface tension and protein backbone solvation.We illustrate the difficulties in interpreting the thermodynamic information based on structural and dynamic arguments.As an alternative,we show that the solvation properties of ions and proteins/small molecules can be used to explain the salt effects on the thermodynamic properties of the solutions.Our analysis shows that the often neglected cation-anion cooperativity plays a very important role in these effects.We also argue that the change of hydrogen donor/acceptor equilibrium by added cosolutes/cosolvents can be used to explain their effects on protein secondary structure denaturation/protection:those increase hydrogen donor concentrations such as urea and salts with strongly solvated cations/weakly hydrated anions tend to dissolve protein backbone acting as secondary structure denaturants,whereas those lack of hydrogen donors but rich in acceptors have the opposite effect.
文摘The solvation of carbon dioxide in sea water plays an important role in the carbon circle and the world climate. The salting-out/salting-in mechanism of CO2 in electrolyte solutions still remains elusive at molecule level. The ability of ion salting-out/salting-in CO2 in electrolyte solution follows Hofmeister Series and the change of water mobility induced by salts can be predicted by the viscosity B-coefficients. In this work, the chemical potential of carbon dioxide and the dynamic properties of water in aqueous NaCl, KF and NaClO4 solutions are calculated and analyzed. According to the viscosity B-coefficients, NaClO4 （0.012） should salt out the carbon dioxide relative to in pure water, but the opposite effect is observed for it. Our simulation results suggest that the salting-in effect of NaClO4 is due to the strongly direct anion-CO2 interaction. The inconsistency between＂ Hofmeister Series and the viscosity B-coefficient suggests that it is not always right to indicate whether a salt belongs to salting-in or salting-out just from these properties of the salt solution in the absence of solute.
基金The project was supported by the fund of the Council of Scientific and Industrial Research (CSIR), New Delhi, India (9/112 (0389) 2K7-EMR-I).
文摘The effect of electrolytes on the micellar behavior of an amphiphilic drug, chlorpromazine (CPZ) hydrochloride, was studied using cloud point (CP) and dye solubilization techniques. In the presence of KBr, increase in pH led to decrease in the CP of 50 mmol·L-1 drug solution (prepared in 10 mmol·L-1 sodium phosphate (SP) buffer) because of deprotonation of drug molecules at high pH. The visible absorbance increased (due to dye solubilization) with the increase in pH from 6.5 to 6.9, which indicated micellar growth. At fixed pH (6.7), addition of inorganic salts (KF, KCl, and KBr) to drug solutions (50 mmol·L-1) caused an increase in the CP as well as in the visible absorbance, with effectiveness being in the order: F-<Cl-<Br-. The results were discussed on the basis of counter-ion binding and their effect toward micellar growth. Cations (co-ions) also led to an increase in the CP (and also the visible absorbance), with their effectiveness order being Li+ >Na+ >K+, which was explained by considering cognizance of their hydrated radii. Compared with anions, their effect was small. Increase in [CPZ] caused micellar growth and hence the CP as well as the visible absorbance increased. The overall behavior was discussed in terms of electrostatic interactions and micellar growth.
基金National Natural Science Foundation of China(nos.21621001,21835002,U1967215,and 21920102005)the 111 Project(no.B17020)for supporting this work.
文摘Zeolites are of great industrial relevance as catalysts,adsorbents,and ion-exchangers and typically synthesized under hydrothermal conditions.Rational regulation of their crystallization process is of great significance for zeolite production.In this work,we systematically investigate the role of anions in tuning zeolite crystallization via anion introduction including SO_(4)^(2−),F^(−),Cl^(−),Br^(−),I^(−),and SCN^(−) in the sodium form into the SiO2-TPAOH-H2O[tetrapropylammonium hydroxide(TPAOH)]synthetic system of silicalite-1 zeolite.
基金This work was supported by the National Natural Science Foundation of China(No.21871063)Guizhou University(No.YJSCXJH(2019)012).
文摘An un precedented tun able hydrophobic effect in self-assembly of a small cationic organic fluorophore(NI-TPy^(+))-based with aggregation-induced emission(AIE)property was realized in aqueous solution.The amplification of hydrophobicity was found to be significantly dependent upon the increasing aggregates of NI-TPy^(+),which enabled the study of the hydrophobic binding of chaotropic anions with the Hofmeister series.
