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Temperature-dependent aggregation of bio-surfactants in aqueous solutions of galactose and lactose:Volumetric and viscometric approach

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Chinese Journal of Chemical Engineering 2018年第5期26卷 1119-1131页

作者： S.Chauhan Vivek Sharma Maninder Kaur Poonam Chaudhary Department of chemistry Himachal Pradesh University

Modulation in the aggregation behavior of bio-surfactants （bile salts）, sodium cholate （NaC） and sodium deoxycholate （NaDC） in aqueous solutions of carbohydrates （galactose and lactose） have been investigated by measuring the density （ρ）, speed of sound （u） and viscosity （η） of the mixtures at different temperatures 293.15, 298.15, 303.15, 308.15 and 313.15 K. The density and speed of sound data have been used to calculate various volumetric and compressibility parameters such as apparent molar volume （Vφ）, isentropic compressibil- ity （κs）, apparent molar adiabatic compression （κs,φ） to get a better insight into the micellization mechanism of bile salts. Further, the viscosity data have been studied in the light of relative viscosity （ηr） and viscous relaxation time （τ）. Some derived parameters such as free volume （νf）, internal pressure （πi） and molar cohesive energy （MCE） of NaC and NaDC in aqueous solution of saccharides have also been calculated from viscosity data in con- junction with density and speed of sound values. All the calculated and derived parameters provide qualitative information regarding the nature of interactions i.e. solute-solute, solute-solvent and solvent-solvent in the solution.

关键词： Density Speed of sound Apparent molar volumelsentropic compressibility viscosity relative viscosity

Compare on characteristic of different chemical type salt lake brines from Tibet during evaporating

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 310-312页

作者： DONG Jinggang WANG Zhengli SHA Zuoliang YI Lixia Tianjin Key Lab of Marine Resources and Chemistry College of Marine Science and Engineering Tianjin University of Science and Technology

1 Introduction China is a country which has many salt *** is the area where have numerous salt lake,because the sources of water have multiple chemical type,resulting in Tibet salt

关键词： Tibet salt lake brine evaporation-precipitation density pH chemical type relative viscosity

Volumetric and Viscometric Studies of 4-Aminobutyric Acid in Aqueous Solutions of Salbutamol Sulphate at 308.15, 313.15 and 318.15K

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Chinese Journal of Chemical Engineering 2009年第5期17卷 796-804页

作者： K. Rajagopal S.S. Jayabalakrishnan Departrnent of Physics Government College ofEngg Tirunelveli-627007 Tamil Nadu India Department of Physics P.S.R. Engg. College Sivakasi Tamil Nadu India

Density （ρ） and viscosity （η） measurements were carried out for 4-aminobutyric acid in 0.0041,0.0125 and 0.0207 mol·L-1 aqueous salbutamol sulphate at T=308.15,313.15 and *** measured values of density and viscosity were used to estimate some important parameters such as apparent molar volume Vφ,limiting apparent molar volume Vφ0,transfer volume △Vφ0,hydration number Hn,second derivative of infinite dilution of partial molar volume with temperature 2Vφ0/T2,viscosity B-coefficients,variation of B with temperature dB/dT,free energy of activation per mole of solvent △μ10＊ and solute △μ20＊,activation entropy △S20＊ and activation enthalpy △H20＊ of the amino *** parameters have been interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.

关键词： density standard partial molar volume hydration ntnZnber relative viscosity B-coefficient activation parameters

Using PVP/SDS Complex as a Probe to Study the Inclusion Complex of β-cyclodextrin with SDS in Aqueous Solution

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Chinese Journal of Chemical Physics 2009年第5期22卷 541-544,I0002页

作者： Xiao-ming Chen Hai-yang Yang Ping-sheng He Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230025 China

PVP/SDS complex was applied as a probe to study the interaction between β-cyclodextrin （β-CD） and sodium dodecyl sulfate （SDS） in aqueous solution. It has been found that a critical concentration, namely cs, exists in the relative viscosity of solution containing PVP/SDS complex versus β-CD concentration plot. As the β-CD concentration is less than cs, the relative viscosity of solution decreases sharply by adding β-CD into solution successively. On the other hand, as the β-CD concentration is greater than cs, the relative viscosity of solution increases gradually by adding β-CD into solution. The decrease of the relative viscosity of solution containing PVP/SDS in the presence of β-CD is just due to the inclusion complex of β-CD with the guest molecule SDS. And, this inclusion interaction takes down SDS from the PVP chains in solution. The ratio of the host molecule β-CD to the guest molecule SDS can be calculated from Cs. In our experiment the inclusion ratio of β-CD to SDS is 1/1. The further experimental results indicate that cs is associated with SDS but free from PVP in PVP/SDS complex. However, the inclusion ratio of β-CD to SDS has proved to be independent of either SDS or PVP in PVP/SDS complex.

关键词： PVP/SDS complex β-cyclodextrin relative viscosity Inclusion ratio

A Perspective on Rheological Studies of Gas Hydrate Slurry Properties

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Engineering 2018年第3期4卷 321-329页

作者： Ahmad A.A. Majid David T. Wu Carolyn A. Koh Center for Hydrate Research Chemical and Biological Engineering Colorado School of Mines Golden CO 80401 USA faculty of Chemical and Natural Resources Engineering Universiti Malaysia Pahang Pekan 26600 Malaysia Department of Chemistry Colorado School of Mines Golden CO 80401 USA

Gas hydrates are solid inclusion compounds that are composed of a three-dimensional hydrogen-bonded network of water cages that can trap small gas molecules, such as methane and carbon dioxide. Understanding the rheological properties of gas hydrate crystals in solution can he critical in a number of energy applications, including the transportation of natural gas in suhsea and onshore operations, as well as technological applications for gas separation, desalination, or sequestration. A number of exper- imental and modeling studies have been done on hydrate slurry rheology; however, the link between theory and experiment is not well-defined. This article provides a review on the current state of the art of hydrate slurry viscosity measurements from high- and low-pressure rheometer studies and high-pressure flowloops over a range of different sub-cooling （ATsub = TequiI Texp） and fluid conditions, including for water and oil continuous systems. The theoretical models that have been developed to describe the gas hydrate slurry relative viscosity are also reviewed. Perspectives＇ linkage between the experiments and theory is also discussed.

关键词： relative viscosity Flow assurance Rheometer Oil-continuous

Viscometric Studies of Some Amino Acids/Peptides in Aqueous K₂SO₄/KNO₃ Solutions at Different Temperatures (298.15 - 323.15 K)

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American Journal of Analytical Chemistry 2023年第2期14卷 72-94页

作者： Umaima Gazal Riyazuddeen Department of Chemistry Aligarh Muslim University Aligarh India Raja Bahadur Venkata Rama Reddy Women’s College Hyderabad India

Viscosities of L-leucine/L-glutamine/L-alanine/glycylglycine + 0.512 mol·kg-1 aqueous K2SO4/0.512mol·kg-1 aqueous KNO3 solutions have been measured as a function of molal concentration of amino acids/peptides at different temperatures (298.15, 303.15, 308.15, 313.15, 318.15 and 323.15) K. Using the viscosity values of the studied systems the viscosity B-coefficients and activation parameters: , , and have been computed. The B-coefficient is a quantity of active solvodynamic measurements of solvated ion and also is overseen through magnitude and form properties of solute, and the basic effects made by means of the solute-solvent functioning. The experimental and computed parameters have been discussed in terms of ion-ion, hydrophilicion and hydrophobicion interactions operative in the systems.

关键词： viscosity relative viscosity Specific viscosity B-Coefficient Activation Parameter Amino Acid Peptide Salt