Naslov
"Jumping Crystals"-New Materials for Clean Conservation of Light and Thermal Energy Into Mechanical Motion

Autori
Skoko, Željko ; Naumov, Panče

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
Programme, Lecture notes & Poster Abstracts, Vol. 2, 44th Course, The power of powder diffraction / David, Bill ; Kenneth Shankland (ur.). - Erice / - , 2011, 396-396

Skup
44th Course of International School of Crystallography, The power of powder diffraction

Mjesto i datum
Erice, Italija, 02.06.2011. - 12.06.2011

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
thermosalient effect; nanotechnology; sigle crystal x-ray diffraction

Sažetak
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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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