Thermally stimulated currents (TSCs) of Langmuir-Blodgett films

Abstract

This paper describes the thermally stimulated currents(TSCs) of arachidic acid(AA) and polyamic acid alkylamine salts(PAAS) Langmuir-Blodgett(LB) films. The measurements were performed from room temperature to about 250 degrees C and the temperature was increased at a rate of 0.02 degrees C/s linearly. Peaks of TSCs are observed at about 80 degrees C in the arachidic acid LB films, and at about 80 degrees C and 16 0 degrees C in the PAAS LB films. They indicate that the peak at 80 degrees C is resulted from alkyl group, and the other peak at 160 degrees C is due to alkyl and C-O group in PAAS molecules. The additional large peak at about 160 degrees C is due to dipole moments of the PAAS molecules. Differential scanning calorimetry(DSC) and thermogravimetric analysis (TGA) of the PAAS and arachidic acid molecules were measured and analyzed.