Semifluorinated alkanes and alkanes: a phase study of the perfluorohexyloctane - tetradecane system

التفاصيل البيبلوغرافية
العنوان: Semifluorinated alkanes and alkanes: a phase study of the perfluorohexyloctane - tetradecane system
المؤلفون: Runnsjö, Anna, Kocherbitov, Vitaly, Graf, Gesche, Pettigrew, Anthony, Scherer, Dieter, Mortensen, Kell, Engblom, Johan
المصدر: Journal of Chemical Thermodynamics. 105:352-361
مصطلحات موضوعية: SFA, perfluorohexyloctane, Phase diagram, tetradecane, F6H8
الوصف: The binary system perfluorohexyloctane (F6H8)–tetradecane (C14) was investigated in order to increase understanding of interactions of semifluorinated alkanes (SFAs) with hydrophobic molecules. The thermal phase behavior for F6H8 and C14 and their mixtures was determined using DSC. The activity coefficients for both components in the mixtures were calculated and Gibbs energy of mixing was determined. Furthermore, enthalpies of mixing were determined with ITC and structural investigations of the solid and the liquid phases were performed with SAXS and SWAXD. It was found that F6H8 displays one solid-solid transition at −42.3 °C (ΔH = 1.1 kJ/mol) and one solid-liquid transition at −5.9 °C (ΔH = 16.6 kJ/mol). Due to the low enthalpy of the solid-liquid transition it is likely that F6H8 is not fully crystallized in the solid phase but partly amorphous. The F6H8–C14 system displays a eutectic phase behavior and the liquid mixtures display a positive deviation from ideal mixing. C14 crystalizes in a triclinic unit cell as shown before, whereas crystallization of F6H8 in a lamellar rippled phase is shown for the first time. This ripple phase comprises a bilayer of tilted alternating heavily interdigitated F6H8 molecules in an oblique subunit cell.
وصف الملف: print
URL الوصول: https://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-14717
قاعدة البيانات: SwePub
الوصف
تدمد:00219614
10963626
DOI:10.1016/j.jct.2016.10.032