Using broadband dielectric spectroscopy the molecular mobility of dibucaine is investigated in the supercooled liquid and gassy states, over a wide temperature range for some test frequencies. Above the glass transition temperature T-g, the presence of structural alpha- relaxation peak was observed due to the cooperative motions of the molecule and upon cooling frozen kinetically to form the glass. The secondary relaxation process was perceivable below T-g due to localized motions. The peak loss frequency of alpha-relaxation process shows non-Arrhenius behavior and obeys Vogel-Fulcher-Tammann equation over the measured temperature range whereas the beta- process shows Arrhenius behavior.
Relaxation dynamics of amorphous dibucaine using dielectric studies
CAPACCIOLI, SIMONE
2015-01-01
Abstract
Using broadband dielectric spectroscopy the molecular mobility of dibucaine is investigated in the supercooled liquid and gassy states, over a wide temperature range for some test frequencies. Above the glass transition temperature T-g, the presence of structural alpha- relaxation peak was observed due to the cooperative motions of the molecule and upon cooling frozen kinetically to form the glass. The secondary relaxation process was perceivable below T-g due to localized motions. The peak loss frequency of alpha-relaxation process shows non-Arrhenius behavior and obeys Vogel-Fulcher-Tammann equation over the measured temperature range whereas the beta- process shows Arrhenius behavior.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
