Thermodynamics of micellar systems: activity and entropy of sodium decanoate and n-alkylamine hydrobromides in water

1981 ◽  
Vol 59 (13) ◽  
pp. 1865-1871 ◽  
Author(s):  
Rosario De Lisi ◽  
Gérald Perron ◽  
Jean Paquette ◽  
Jacques E. Desnoyers
Keyword(s):  
Heat Capacity ◽  
Aqueous Solutions ◽  
Homologous Series ◽  
Freezing Point ◽  
Activity Data ◽  
Micellar Systems ◽  
Point Data ◽  
Sodium Decanoate ◽  
Capacity Data ◽  
Mean Activity Coefficients

The freezing-point depressions of aqueous solutions of the homologous series RNH3Br, where R varies from ethyl to n-octyl, and of sodium decanoate were determined and used to calculate osmotic and mean activity coefficients. In the case of the surfactants octylamine hydrobromide and sodium decanoate, the pre- and post-micellar regions were covered. Activity data at higher temperatures were calculated using previously published thermochemical data. Some difficulties arise in the critical micellar region of sodium decanoate at high temperatures as a result of the large concentration and temperature dependence of the heat capacity data. The activities from freezing point data are compared with those obtained from specific electrodes.

PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XII. ANTIFREEZE PROPERTIES OF TERNARY AQUEOUS SOLUTIONS CONTAINING LEVO-2,3-BUTANEDIOL AS A MAJOR COMPONENT

1946 ◽  
Vol 24f (5) ◽  
pp. 287-299 ◽  
Author(s):  
K. A. Clendenning ◽  
D. E. Wright
Keyword(s):  
Ethylene Glycol ◽  
Aqueous Solutions ◽  
Boiling Point ◽  
Freezing Point ◽  
Ternary Systems ◽  
Freezing Points ◽  
Point Depressant ◽  
Point Data ◽  
Considerable Range

Freezing point, viscosity, and boiling point data are presented for aqueous solutions of levo-2,3-butanediol containing methanol, ethanol, ethylene glycol, and tetrahydrofurfuryl alcohol as third components. All four ternary systems show freezing points of −50 °C. and lower over a considerable range of compositions. Among the compounds tested as third components, methanol was most effective as a thinning agent and accessory freezing point depressant. The data indicate that 20% methanol–40% butanediol–40% water is suitable for use at temperatures as low as −50 °C.

scholarly journals Model for estimating activity coefficients in binary and ternary ionic surfactant solutions

2020 ◽  
Vol 77 (4) ◽  
pp. 141-168
Author(s):  
Silvia M. Calderón ◽  
Jussi Malila ◽  
Nønne L. Prisle
Keyword(s):  
Aqueous Solutions ◽  
Water Activity ◽  
Activity Coefficients ◽  
Ternary Systems ◽  
Inorganic Salts ◽  
Ionic Surfactant ◽  
Activity Data ◽  
Chloride System ◽  
Wide Range ◽  
Sodium Decanoate

AbstractWe introduce the CMC based Ionic Surfactant Activity model (CISA) to calculate activity coefficients in ternary aqueous solutions of an ionic surfactant and an inorganic salt. The surfactant can be either anionic or cationic and in the present development, the surfactant and inorganic salts share a common counterion. CISA incorporates micellization into the Pitzer–Debye–Hückel (PDH) framework for activities of mixed electrolyte solutions. To reduce computing requirements, a parametrization of the critical micelle concentration (CMC) is used to estimate the degree of micellization instead of explicit equilibrium calculations. For both binary and ternary systems, CISA only requires binary experimentally-based parameters to describe water–ion interactions and temperature–composition dependency of the CMC. The CISA model is intended in particular for atmospheric applications, where higher-order solution interaction parameters are typically not constrained by experiments and the description must be reliable across a wide range of compositions. We evaluate the model against experimental activity data for binary aqueous solutions of ionic surfactants sodium octanoate and sodium decanoate, as common components of atmospheric aerosols, and sodium dodecylsulfate, the most commonly used model compound for atmospheric surfactants. Capabilities of the CISA model to describe ternary systems are tested for the water–sodium decanoate–sodium chloride system, a common surrogate for marine background cloud condensation nuclei and to our knowledge the only atmospherically relevant system for which ternary activity data is available. For these systems, CISA is able to provide continuous predictions of activity coefficients both below and above CMC and in all cases gives an improved description of the water activity above the CMC, compared to the alternative model of Burchfield and Wolley [J. Phys. Chem., 88(10), 2149–2155 (1984)]. The water activity is a key parameter governing the formation and equilibrium growth of cloud droplets. The CISA model can be extended from the current form to include the effect of other inorganic salts with the existing database of binary PDH parameters and using appropriate mixing rules to account for ion specificity in the micellization process.

Development of the room temperature protocol based on room temperature ionic liquids and surfactant ionic liquids for the synthesis of derivatives of 2-amino-thiazoles and thermo-physical analysis of the synthesized derivatives using TGA-DSC.

2020 ◽  
Vol 10 ◽  
Author(s):  
Chandrakant Sarode ◽  
Sachin Yeole ◽  
Ganesh Chaudhari ◽  
Govinda Waghulde ◽  
Gaurav Gupta
Keyword(s):  
Thermal Analysis ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Room Temperature ◽  
Heat Capacity Data ◽  
General Strategy ◽  
Capacity Data ◽  
Derivatives Of

Aims: To develop an efficient protocol, which involves an elegant exploration of the catalytic potential of both the room temperature and surfactant ionic liquids towards the synthesis of biologically important derivatives of 2-aminothiazole. Objective: Specific heat capacity data as a function of temperature for the synthesized 2- aminothiazole derivatives has been advanced by exploring their thermal profiles. Method: The thermal gravimetry analysis and differential scanning calorimetry techniques are used systematically. Results: The present strategy could prove to be a useful general strategy for researchers working in the field of surfactants and surfactant based ionic liquids towards their exploration in organic synthesis. In addition to that, effect of electronic parameters on the melting temperature of the corresponding 2-aminothiazole has been demonstrated with the help of thermal analysis. Specific heat capacity data as a function of temperature for the synthesized 2-aminothiazole derivatives has also been reported. Conclusion: Melting behavior of the synthesized 2-aminothiazole derivatives is to be described on the basis of electronic effects with the help of thermal analysis. Additionally, the specific heat capacity data can be helpful to the chemists, those are engaged in chemical modelling as well as docking studies. Furthermore, the data also helps to determine valuable thermodynamic parameters such as entropy and enthalpy.

scholarly journals Estimating a Stoichiometric Solid’s Gibbs Free Energy Model by Means of a Constrained Evolutionary Strategy

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 471
Author(s):  
Constantino Grau Turuelo ◽  
Sebastian Pinnau ◽  
Cornelia Breitkopf
Keyword(s):  
Heat Capacity ◽  
Free Energy ◽  
Evolutionary Strategy ◽  
Data Sets ◽  
Automatic Data ◽  
Physical Constraints ◽  
Stoichiometric Model ◽  
Covariance Matrix Adaptation ◽  
Dsc Measurements ◽  
Capacity Data

Modeling of thermodynamic properties, like heat capacities for stoichiometric solids, includes the treatment of different sources of data which may be inconsistent and diverse. In this work, an approach based on the covariance matrix adaptation evolution strategy (CMA-ES) is proposed and described as an alternative method for data treatment and fitting with the support of data source dependent weight factors and physical constraints. This is applied to a Gibb’s Free Energy stoichiometric model for different magnesium sulfate hydrates by means of the NASA9 polynomial. Its behavior is proved by: (i) The comparison of the model to other standard methods for different heat capacity data, yielding a more plausible curve at high temperature ranges; (ii) the comparison of the fitted heat capacity values of MgSO4·7H2O against DSC measurements, resulting in a mean relative error of a 0.7% and a normalized root mean square deviation of 1.1%; and (iii) comparing the Van’t Hoff and proposed Stoichiometric model vapor-solid equilibrium curves to different literature data for MgSO4·7H2O, MgSO4·6H2O, and MgSO4·1H2O, resulting in similar equilibrium values, especially for MgSO4·7H2O and MgSO4·6H2O. The results show good agreement with the employed data and confirm this method as a viable alternative for fitting complex physically constrained data sets, while being a potential approach for automatic data fitting of substance data.

Density and viscosity of aqueous solutions of methanol and acetone from the freezing point to 10.deg.

1971 ◽  
Vol 16 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Fred. Kurata ◽  
Thomas W. Yergovich ◽  
George W. Swift
Keyword(s):  
Aqueous Solutions ◽  
Freezing Point

scholarly journals XVII.—Electrolytic Synthesis of Dibasic Acids

1895 ◽  
Vol 37 (2) ◽  
pp. 361-379
Author(s):  
A. Crum Brown ◽  
James Walker
Keyword(s):  
Aqueous Solutions ◽  
Succinic Acid ◽  
Homologous Series ◽  
Side Chains ◽  
Potassium Salts ◽  
Concentrated Aqueous Solutions

In our former paper we described the results obtained by electrolysing concentrated aqueous solutions of the ethyl-potassium salts of normal saturated dibasic acids. The chief products were shown to be diethyl compound ethers of the same homologous series, and the formation of these compound ethers was shown to occur in accordance with the equation: 2C2H5·O·ĊO·R˝·CO·O- = C2H5·O·CO·R˝R˝CO·O·C2H5 + 2CO2. We now find that precisely similar results are obtained by electrolysing the corresponding compounds derived from saturated dibasic acids with side chains. We have thus been able to effect the synthesis of acids of the succinic acid series, in which hydrogen is symmetrically replaced by alcohol radicals of the form CnH2n+1.

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