Investigations of the Thermal Properties, Nucleation Kinetics, and Growth of γ-Aminobutyric Acid in Aqueous Ethanol Solution

DSC studies show that a sample starts to melt at 190.6 °C with a high melting enthalpy of 343.4 J/g. Using a laser monitoring system, the solubility of γ-aminobutyric acid in aqueous ethanol solution was measured by a synthetic method at temperatures ranging from 288.2 to 313.2 K and at atmospheric pressure; these are important data for the crystallization process of γ-aminobutyric acid from its aqueous solution. The measured solubility was correlated with the Buchowski−Ksiazczak equation and the modified Apelblat equation. Then, the induction of γ-aminobutyric acid in ethanol was estimated at different temperatures. The study reveals that the induction period of γ-aminobutyric acid decreases with increasing supersaturation. Interfacial tension was estimated from the experimentally determined induction period values. Nucleation parameters were also investigated based on classical nucleation theory. The grown crystals were also subjected to structural and thermal studies.