"Jumping Crystals"-New Materials for Clean Conservation of Light and Thermal Energy Into Mechanical Motion (CROSBI ID 578045)
Prilog sa skupa u zborniku | sažetak izlaganja sa skupa
Podaci o odgovornosti
Skoko, Željko ; Naumov, Panče
engleski
"Jumping Crystals"-New Materials for Clean Conservation of Light and Thermal Energy Into Mechanical Motion
The thermosalient solids, which are colloquially also referred to as "jumping crystals", are promising materials for fabrication of actuators - mechanical devices capable for conversion of thermal energy into motion or mechanical work at a macroscopic level. If heated of cooled these materials usually undergo sharp phase transition with strongly anisotropic change of their structure. As a result, the crystals undergo large change in their cell volume (~12% in some inositols) causing such crystals to jump to heights of up to several times their height. With less than ten existing reports, the thermosalient effect ia a very poorly understood phenomenon. The origin of the effect, however, is the key question to be answered, if the mechanism responsible for this unusal, and potentially very useful behaviour is to be explained. As part of our study of thermosalient materials, we investigated oxitropium bromide (OXTB), a pharmaceutical compound which is being used as an anticholinergic drug. When heated, oxtb crystals undergoendothermic phase expansion of 4%, wherupn the b axis stretches 11% and the c axis shrinks 7%. The phase transition is reversible, and it show thermal hysteresis. We succeeded, for the first time, in determining the structure of the high-temperture phase of OXTB. Our results showed that the thermosalient behaviour of OXTB is caused mainly by intramolecular changes in its structure. The process was completely characterized by means of single crystal X-ray diffraction, IR and NMR spectrosclpy and DSC.
thermosalient effect; nanotechnology; sigle crystal x-ray diffraction
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Podaci o prilogu
396-396.
2011.
objavljeno
Podaci o matičnoj publikaciji
Programme, Lecture notes & Poster Abstracts, Vol. 2, 44th Course, The power of powder diffraction / David, Bill ; Kenneth Shankland (ur.). - Erice
Podaci o skupu
44th Course of International School of Crystallography, The power of powder diffraction
poster
02.06.2011-12.06.2011
Erice, Italija