Determination of phase change temperature of materials from adiabatic scanning calorimetry data

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F23%3A00364743" target="_blank" >RIV/68407700:21110/23:00364743 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1007/s10973-022-11335-2" target="_blank" >https://doi.org/10.1007/s10973-022-11335-2</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/s10973-022-11335-2" target="_blank" >10.1007/s10973-022-11335-2</a>

Result language
angličtina
Original language name
Determination of phase change temperature of materials from adiabatic scanning calorimetry data
Original language description
Melting and other first-order phase changes usually occur in phase change materials (PCMs) within a noticeable temperature range rather than at a unique phase change temperature (Tpc). Then the enthalpy and heat capacity have rather wide jumps and peaks, respectively, spread over such ranges of temperatures. Surprisingly, wide jumps and peaks are observed even in plain and simple cases when PCMs are pure substances with negligible hysteresis and/or supercooling and the measurements are quasi-equilibrium using very slow heating/cooling rates, as in adiabatic scanning calorimetry (ASC). We show that in such cases a unique Tpc can be identified and calculated from the measured heat capacity peaks. It suffices to take into account that PCM samples do not have an ideal microstructure but are rather composed of many micro- to nano-sized domains. The heat capacity peak is then an average of individual peaks that (a) come from all domains and (b) have different shifts from Tpc for different domain sizes. Interpreting a heat capacity peak measured by ASC in this way, we present a procedure from which Tpc can be evaluated. We apply the procedure to three examples of materials using available ASC data and point out the importance of the size distribution of domains.
Czech name
—
Czech description
—

Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
—
OECD FORD branch
20501 - Materials engineering

Project
—
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year
2023
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Similar results(10)