Novootkriveni termoodskočni efekt u trifeniltetrazolij kloridu

Thermosalient materials are being studied for more than 30 years, not just for its scientific and industrial potential, but because of its attractive and mysterious nature. As the name says, thermosalient or “jumping” materials are crystals which when heated or cooled down undergo a phase transition which is so sudden and energetic that they jump off up to distances several times larger than their dimensions. Thermosalient effect is usually accompanied with other specific phenomena such as negative thermal expansion. In this work thermosalient effect is demonstrated for the first time in 8 different materials with special attention given to Triphenyltetrazolium Chloride (TTC) and circumstances under which it occurs are shown. For this purpose different experimental and computational methods such as powder x-ray diffraction (PXRD), hot stage microscopy, differential scanning calorimetry, X‘Pert Highscore Plus (for analysis of diffraction measurements) computer software and other tools for statistical data processing and graphical image processing were used. The entire study was performed at a temperature range of -186° C to the melting point of 250° C to fully characterize TO effect in this system. Numerous samples were tested, some of which were recrystallized from 3 different solvents: water, acetone and ethanol, and the rich “behaviour” of the titled compound was observed. As many as five different temperature intervals of jumping, the appearance of negative thermal expansion polymorphism and six different phases above and below room temperature. Hysteresis of the temperature of TO effect was also observed.