Limiting Activity Coefficients for Aqueous Solutions

Measurement techniques for limiting activity coefficients (γ\sp\infty) are reviewed with respect to aqueous solutions. Literature values for γ\sp\infty of solutes in water at 25$\sp\circ$C were compiled and critically evaluated to form a database of high confidence for 120 compounds. Predictive expressions for γ\sp\infty were analyzed for aqueous systems. The use of other thermodynamic measurements such as inverse solubility and hexadecane-water and octanol-water partition coefficients were also evaluated as methods for obtaining γ\sp\infty of solutes in water. A database of inverse solubility of solutes in water was compiled. Differential ebulliometry was used to measure γ\sp\infty over a modest range of temperatures for three solvents in water and water in six solvents. The data were used to demonstrate the limitations of several current excess Gibbs energy expressions in representing both vapor-liquid and liquid-liquid equilibrium data from γ\sp\infty measurements. A new technique for measuring limiting activity coefficients of low relative volatility solutes was developed based on measuring the change in the dew point temperature of a solvent with the dilute addition of a solute. This dew point method was used to measure γ\sp\infty for three solutes in water over a range of temperatures. The low γ\sp\infty values for these solutes indicate solvation occurring in the mixture. Ideal chemical theory was used to model the measured dew point temperatures.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Chemical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Trampe, Diane Bergmann

Contributors dc:contributor

• Eckert, Charles A.

• Engineering, Chemical
• Environmental Sciences

Identifier

(UMI)AAI9329184

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/72144