Authors:M. Matthews, I. Atkinson, Lubaina Presswala, O. Najjar, Nadine Gerhardstein, R. Wei, Elizabeth Rye, and A. Riga
Dielectric analysis (DEA), supported by thermogravimetric analysis (TG), differential scanning calorimetry (DSC), powder X-ray
diffraction analysis (PXRD) and photomicrography, reveal the chiral difference in the amino acids. The acids are classified
as dielectric materials based on their structure, relating chirality to the vector sum of the average dipole moment, composed
of the constant optical (electronic) and infra-red (atomic) polarizabilities, as well as dipole orientation. This study encompasses
14 L-and D-amino acid isomers. Physical properties recorded include AC electrical conductivity, charge transfer complexes, melting,
recrystallization, amorphous and crystalline phases, and relaxation spectra, activation energies and polarization times for
the electrical charging process.
Authors:Lubaina Presswala, M. Matthews, I. Atkinson, O. Najjar, Nadine Gerhardstein, J. Moran, R. Wei, and A. Riga
The thermal analytical study of most hydrophobic and hydrophilic D/L amino acids reveals significant hydropathy index correlation between the presence of water and crystalline amino acids. The
TG derivative mass profiles for arginine and lysine (hydrophilic acids) at various time intervals of atmospheric exposure,
show two distinct peaks, one between 50 and 60°C (unbound water), and one close to 100°C (bound-like water). The DSC heat-cool
profiles for lysine and arginine confirmed the presence of these multiple waters with two heats of vaporization. The absence
of these patterns from the TG and DSC for cysteine and phenylalanine (hydrophobic acids) further supports the conclusions.