Degree Name

Master of Science (MS)

Semester of Degree Completion

1972

Thesis Director

David W. Ebdon

Abstract

Bolaform electrolytes are those which contain two or more charges separated by an inert framework. These are intermediate in structure between simple electrolytes and polyelectrolytes. Since these are similar to both synthetic and biological electrolytes, this investigation has been undertaken to determine some of their properties in solution.

The sodium and magnesium salts of ethane, propane, butane, pentane, hexane and decane α,ω-disulfonates were prepared. Each acid was prepared by refluxing the α,ω-dibromide of the desired salt with sodium sulfite. The sodium and magnesium salts were prepared by ion-exchange techniques.

The conductance of each salt was determined in methanol utilizing the weight dilution method. A data treatment method for unsymmetrical 1-2 electrolytes was tested. The Murphy-Cohen equation: ∧ = ∧° - S√C + E′ClnC + J′C was found to be invalid in the concentration range studied, 1.0 - 5.0 x 10-4moles/liter. The Onsager limiting law when applied to the sodium salt data gave ∧° values from approximately 108 (ohm-1cm2equiv-1) for the ethane salt to 100 (ohm-1cm2equiv-1) for the decane. Phoreograms showed these salts to be unassociated in methanol. The magnesium salts deviated substantially below the limiting law plot and consequently were considered highly associated.

The ∧° values for the magnesium salts were calculated from Kohlrausch's law, ∧° = λ+Mg + λ-anion. By fixing this value, association constants were found to be in a range of 108,950 for the ethane salt to 25,260 for the decane salt. These values show a monotonic decrease as the chain length of the salt increases. This is explained by charge separation considerations. As the chain length increases the charge density on the molecule decreases, illustrating a decrease in ion-ion interactions.

The frictional coefficients of the sodium salts were determined from λ- data. These showed values of .0496 X 10-7 g/sec for the ethane salt to .0563 X 10-7 g/sec for decane salts. The Peterlin rod and bead model for the determination of frictional forces was successfully applied to the data.

The Perrin rigid ellipsoid model did not show any agreement when experimental and theoretical frictional coefficient values were compared.

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