Solid-liquid equilibrium and heat capacity trend in the alkylimidazolium PF6 series
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F17%3A43914614" target="_blank" >RIV/60461373:22340/17:43914614 - isvavai.cz</a>
Result on the web
<a href="https://www.sciencedirect.com/science/article/pii/S0167732217300582" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0167732217300582</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.molliq.2017.10.042" target="_blank" >10.1016/j.molliq.2017.10.042</a>
Alternative languages
Result language
angličtina
Original language name
Solid-liquid equilibrium and heat capacity trend in the alkylimidazolium PF6 series
Original language description
The heat capacity and thermal behavior trend along the 1-alkyl-3-methylimidazolium hexafluorophosphate [CnC1im][PF6] (with n = 2?10, 12) ionic liquids series, is used to explore the effect of the alkyl chain length in the nanostructuration. The heat capacities of the studied ILs were measured with an uncertainty better than ?0.15% and are in excellent agreement with the available data in the literature. An odd-even effect for the specific and volumic heat capacities of the [CnC1im][PF6] series was found. The observed odd-even effect in the liquid heat capacity was rationalized considering the preferential orientation of the terminal -CH3 group. The higher specific/volumic heat capacities shown for the [C6C1im][PF6] and [C8C1im][PF6] are an indication of an additional conformational disorder increase in the liquid phase that could be related with a weaker alkyl chain interdigitation capability of the even number chain ILs. The melting temperature and consequent enthalpy and and entropy of fusion trend along the alkyl series present a V-shape profile that is explained based on the analysis of the balance between the initial decrease of the electrostatic interaction potential and the increase of the van der Waals interactions with the increasing size of the alkyl side chain of the cation. The inhibition of crystallization for intermediate alkyl chain size (from [C5C1im][PF6] to [C8C1im][PF6]) seems to arise from the overlapping of the hypothetical cold crystallization temperature by the melting temperature. Above the critical alkyl size, CAS, a regular increase in the entropy and enthalpy profiles presents a similar shape than the observed in other alkane series and is a strong support of the intensification of the ILs nanostructuration.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10403 - Physical chemistry
Result continuities
Project
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Continuities
S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2017
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Molecular Liquids
ISSN
0167-7322
e-ISSN
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Volume of the periodical
248
Issue of the periodical within the volume
14. říjen 2017
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
10
Pages from-to
"678?687"
UT code for WoS article
000418314400082
EID of the result in the Scopus database
2-s2.0-85032347291