TY - JOUR
T1 - Thermodynamic parameters of Rhodamine B in powder and nanofilms forms
AU - Hikal, Walid M.
AU - Paden, Jeffrey T.
AU - Bhattacharia, Sanjoy
AU - Weeks, Brandon
PY - 2013/8
Y1 - 2013/8
N2 - We report the use of UV-Vis absorbance spectroscopy in determining
thermodynamic properties of materials based on their absorbance in the
visible region of the electromagnetic spectrum. Rhodamine B (RhB) dye
which has always been considered to be a non-volatile material, was
chosen for the validation of this method because of its well-defined and
strong absorbance in this region. Continuous films of RhB suitable for
absorbance spectroscopic study were prepared by spin coating in a 0.2 M
ethanol solution to determine the sublimation rates and the activation
energy of RhB in the temperature range 65-100 A degrees C. For
comparison, the same thermodynamic parameters of powder RhB were also
determined using thermogravimetric analysis, at higher temperatures
(100-180 A degrees C). The sublimation of RhB was determined to be a
first-order process by both methods. The activation energies of
sublimation calculated by both techniques are in very good agreement.
However, the sublimation rates c
AB - We report the use of UV-Vis absorbance spectroscopy in determining
thermodynamic properties of materials based on their absorbance in the
visible region of the electromagnetic spectrum. Rhodamine B (RhB) dye
which has always been considered to be a non-volatile material, was
chosen for the validation of this method because of its well-defined and
strong absorbance in this region. Continuous films of RhB suitable for
absorbance spectroscopic study were prepared by spin coating in a 0.2 M
ethanol solution to determine the sublimation rates and the activation
energy of RhB in the temperature range 65-100 A degrees C. For
comparison, the same thermodynamic parameters of powder RhB were also
determined using thermogravimetric analysis, at higher temperatures
(100-180 A degrees C). The sublimation of RhB was determined to be a
first-order process by both methods. The activation energies of
sublimation calculated by both techniques are in very good agreement.
However, the sublimation rates c
M3 - Article
SP - 519
EP - 523
JO - Journal of Thermal Analysis and Calorimetry
JF - Journal of Thermal Analysis and Calorimetry
SN - 1388-6150
ER -