TY - JOUR
T1 - Estimating the nonideality of eutectic systems containing thermally unstable substances
AU - Alhadid, Ahmad
AU - Jandl, Christian
AU - Nasrallah, Sahar
AU - Kronawitter, Silva M.
AU - Mokrushina, Liudmila
AU - Kieslich, Gregor
AU - Minceva, Mirjana
N1 - Publisher Copyright:
© 2023 Author(s).
PY - 2023/9/7
Y1 - 2023/9/7
N2 - Eutectic systems design requires an in-depth understanding of their solid-liquid equilibria (SLE). Modeling SLE in eutectic systems has as prerequisites, the melting properties and activity coefficients of components in the liquid phase. Thus, due to the unavailable melting properties of thermally unstable substances, it is impossible to estimate their activity coefficients from experimental SLE data and model the SLE phase diagram of their eutectic systems. Here, we evaluate the activity coefficients of thermally unstable constituents in the liquid phase, which were calculated independent of their melting properties by correlating the SLE data of their cocrystals. Differential scanning calorimetry and powder x-ray diffraction were employed to obtain the SLE phase diagram of three eutectic systems, i.e., tetramethylammonium chloride/catechol, tetraethylammonium chloride/catechol, and betaine/catechol systems, and identify the formation of nine cocrystals. The non-random, two-liquid equation was used to calculate the activity coefficients of the components in the liquid phase. The substantial negative deviation from ideality in the three studied systems indicated strong hydrogen bonding interactions in the liquid solution. Furthermore, modeling ion-ion interactions in eutectic systems containing ionic constituents is of utmost importance for understanding their nonideality.
AB - Eutectic systems design requires an in-depth understanding of their solid-liquid equilibria (SLE). Modeling SLE in eutectic systems has as prerequisites, the melting properties and activity coefficients of components in the liquid phase. Thus, due to the unavailable melting properties of thermally unstable substances, it is impossible to estimate their activity coefficients from experimental SLE data and model the SLE phase diagram of their eutectic systems. Here, we evaluate the activity coefficients of thermally unstable constituents in the liquid phase, which were calculated independent of their melting properties by correlating the SLE data of their cocrystals. Differential scanning calorimetry and powder x-ray diffraction were employed to obtain the SLE phase diagram of three eutectic systems, i.e., tetramethylammonium chloride/catechol, tetraethylammonium chloride/catechol, and betaine/catechol systems, and identify the formation of nine cocrystals. The non-random, two-liquid equation was used to calculate the activity coefficients of the components in the liquid phase. The substantial negative deviation from ideality in the three studied systems indicated strong hydrogen bonding interactions in the liquid solution. Furthermore, modeling ion-ion interactions in eutectic systems containing ionic constituents is of utmost importance for understanding their nonideality.
UR - http://www.scopus.com/inward/record.url?scp=85169759591&partnerID=8YFLogxK
U2 - 10.1063/5.0158985
DO - 10.1063/5.0158985
M3 - Article
C2 - 37671963
AN - SCOPUS:85169759591
SN - 0021-9606
VL - 159
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 9
M1 - 094503
ER -