Experimental studies of the ortho-toluidine glass transition.
The thermodynamic and dynamics proprieties of ortho-toluidine, in the vicinity of a glass transition, have been studied by calorimetric and by two light scattering techniques, depolarized light scattering and time-resolved optical Kerr effect. Differential scanning microcalorimetry clearly detects a glass transition in o-toluidine and it measures some thermodynamics critical parameters, in particular, the transition temperature. The light scattering data have been analyzed according to the mode-coupling theory. This theory gives a good interpretation of our data and it allows to extract safely the critical parameters of the o-toluidine dynamics. We found a fair agreement between the analysis outputs performed in the frequency domain and in the time domain. Finally, we compared the glass transition features of o-toluidine with that of its isomer meta-toluidine, looking for some general idea about the molecular aspects of the glass transition.
Pratesi
G
G
INFM (Instituto Nazionale per la Fisica della Materia), UdR di Firenze, Polo Scientifico, G. Sansone 1, I-50019 Sesto, Firenze, Italy.
Bartolini
P
P
Senatra
D
D
Ricci
M
M
Righini
R
R
Barocchi
F
F
Torre
R
R