CRYOSCOPIC AND DYNAMIC STUDY OF THE MOLTEN SYSTEM FLUOROACETAMIDE-SODIUM TRIFLUOROACETATE

The behavior of the molten system acetamide-electrolyte, including the peculiarity of the structure and the consequent relevant properties, such as the megavalue of the dielectric constant, was reported earlier . The probable structure is a micellar system composed of salt micelle s dispersed in an amorphous solvent. The present paper reports measure ments in a related system: fluoroacetamide-sodium trifluoroacetate. Th e phase diagram, the ultrasonic absorption of both longitudinal and sh ear waves, and the longitudinal relaxation time of the nuclear magneti c momentum were measured at different temperatures. The most important result was that T-1 (NMR relaxation time) on the F-19 nucleus shows t hat the amide and salt participate in different environments. The amid e environment is less rigid; this proves that the system must be consi dered microheterogeneous. Moreover, the present system exhibited: 1) a less extended concentration area where supercooling phenomena occur; 2) a much broader curve of the real part of the mechanical impedance v ersus frequency; 3) a higher bulk viscosity in comparison with the CH3 CONH2CF3COONa supercapacitive system.