Please use this identifier to cite or link to this item:
https://hdl.handle.net/10216/103615
Author(s): | Adélio Mendes José C. S. Costa Carlos F. R. A. C. Lima Luís M. N. B. F. Santos |
Title: | Fluorination effect on the thermodynamic properties of long-chain hydrocarbons and alcohols |
Issue Date: | 2016 |
Abstract: | Structural and thermodynamic insights are reported for the series of fluorinated alcohols {oFTOH; CF3(CF2)nCH2OH, with n = 5-12}, with the objective of comparing the phase behaviour of perfluorinated compounds with the analogous linear alkanes and alcohols. As expected the higher vibrational contribution of the -CF2- groups contributes for the higher heat capacities of the perfluorinated compounds. Concerning the fusion/sublimation equilibria, fluorination of the alcohols decreases DH and DS of phase transitions. Compared to the regular -CH2- alkyl chain structure, the less symmetric -CF2- spiral conformation is characterized by a less efficient molecular alignment in crystal packing, thus explaining the lower DH. The lower internal rotational barrier associated with the -CH2- alkyl chains of n-alkanes/alcohols, when compared to -CF2- chains, contributes to the larger values of DS observed. Regarding the vaporization equilibria, fluorination leads to greater values of DS, which are explained by the larger translational entropy of the heavier perfluoroalcohols, an effect that is more important in the gas than in the liquid phase. |
Subject: | Ciências Tecnológicas Technological sciences |
URI: | https://hdl.handle.net/10216/103615 |
Related Information: | info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e a Tecnologia/Projetos Estratégicos/UID/EQU/00511/2013 - POCI-01-0145-FEDER-006939/Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia/LEPABE |
Document Type: | Artigo em Revista Científica Internacional |
Rights: | restrictedAccess |
Appears in Collections: | FCUP - Artigo em Revista Científica Internacional FEUP - Artigo em Revista Científica Internacional |
Files in This Item:
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145498.pdf Restricted Access | Artigo original publicado | 1.08 MB | Adobe PDF | Request a copy from the Author(s) |
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