Adsorption Isotherms of Limonene Enantiomers on the Surface of Chiral Triglycine Sulfate Crystals

The adsorption of limonene enantiomers on chiral crystals of the ferroelectric triglycine sulfate was investigated. Homochiral crystals were synthesized under Viedma maturation conditions. Adsorption isotherms were obtained at temperatures below the Curie point (at 45 degrees C), above the Curie point (100 degrees C), and below the Curie point after heating at 100 degrees C. Van Deemter curves for limonene enantiomers on the sample were constructed. Differences in equilibrium adsorption values were validated using the t-test. It was found that, below the Curie point, a difference in the adsorption isotherms of the limonenes is observed in the nonlinear adsorption isotherm region. At 100 degrees C, no differences in the isotherms were observed. Furthermore, when the column temperature was reduced back to 45 degrees C, no differences were observed either. It can be concluded that triglycine sulfate crystals do not possess chiral memory and that transition into the para-phase leads to irreversible loss of homochirality.