Scopul nostru este sprijinirea şi promovarea cercetării ştiinţifice şi facilitarea comunicării între cercetătorii români din întreaga lume.
Autori: A. Rotaru, A. Kropidlowska, A. Moanta, P. Rotaru, E. Segal
Editorial: Journal of Thermal Analysis and Calorimetry, 92 (1), p.233-238, 2008.
Thermal analysis of three azomonoethr dyes, exhibiting liquid crystalline properties, was performed in dynamic air atmosphere. Thermal stability studies and the evaluation of the kinetic parameters of each physical or chemical transformation are essential for a full characterization, before attempting accurate thin films’ depositions of such materials used in non-linear optical applications. New synthesized dyes with general formula:
,where R is a nematogenic group: CN, CF3 or a highly polarizable group: NO2 were investigated using TG, DTG, DTA and DSC techniques, under non-isothermal regime. The evolved gases were analyzed by FTIR spectroscopy. The activation energies of the first decomposition steps were evaluated for each compound, the obtained results revealing complex mechanisms.
Cuvinte cheie: : liquid crystals, dyes, thermal analysis, non-isothermal kinetics, isoconversional methods