QUARTZ CRYSTAL MICROBALANCE / HEAT CONDUCTION CALORIMETRY STUDY OF SOLVENT SORPTION IN THIN C_(60) AND C_(60)-PIPERAZINE FILMS

摘要

The quartz crystal microbalance / heat conduction calorimeter (QCM / HCC) developed in our laboratory has been used to investigate the sorption of water and organic solvents in thin films of C_(60) and C_(60)-piperazine mnoadduct. Films of 1-5 μ thickness and 2 cm~2 area were spray-deposited on the quartz crystal microbalance surface, and were then exposed in QCM/HCC to various partial pressures of solvent vapor in a N_2 carrier gas at 25℃. Solvents included water, 1,3-dichlorobenzene, carbon tetrachloride, and methylene chloride. Simultaneous measurement of mass uptake and heat dissipation in the film at 25℃ as a function of solvent partial pressure gives new information on the thermodynamics and kinetics of solvate formation in C_(60) and C_(60)-piperazine, complementing prior studies of solvate formation with differential scanning calorimetry. QCM/HCC studies also show if the solvate formation at 25℃ is irreversible or if the solvate is easily decomposed at low solvent vapor pressures.