Bitte benutzen Sie diese Referenz, um auf diese Ressource zu verweisen: doi:10.22028/D291-28981
Volltext verfügbar? / Dokumentlieferung
Titel: Lamellar structures in fluorinated phosphonium ionic liquids: the roles of fluorination and chain length
VerfasserIn: Rauber, Daniel
Zhang, Peng
Huch, Volker
Kraus, Tobias
Hempelmann, Rolf-Wilhelm
Sprache: Englisch
Titel: Physical chemistry, chemical physics : PCCP
Bandnummer: 19
Heft: 40
Startseite: 27251
Endseite: 27258
Verlag/Plattform: RSC
Erscheinungsjahr: 2017
Dokumenttyp: Journalartikel / Zeitschriftenartikel
Abstract: Ionic liquids (ILs) exhibit tunable behaviour and properties that are due to their supramolecular structure. We synthesized a series of alkylated and fluorinated phosphonium dicyanamide ILs to study the relation between molecular structure and assembly with a focus on the roles of cation chain length and fluorination. Small angle X-ray scattering indicated a lamellar structure with long-range order for all fluorinated ILs, while alkylated ILs showed only the general structures of ILs, i.e., alternating a polar ionic-zone and a nonpolar alkyl-zone. “Fluorophobic” interactions caused microphase segregation between perfluorinated and other molecular segments, “fluorophilic” interactions among the perfluorinated segments stabilized the microphase structure, and the coupling of “fluorophobic” and “fluorophilic” interactions resulted in a stable mesophase structure. The perfluorinated segments packed more densely than the alkylated analogues; the fluorinated versions (except for F2) liquefied at temperatures considerably above that of alkylated ILs. The lamellar structures strongly affected the rheology of the ILs. Fluorinated ILs had higher viscosities and exhibited non-Newtonian shear thinning; the alkylated ILs of the same length had an order of magnitude lower viscosities and were purely Newtonian. We propose that the disruption of lamellar structure in the shear flow causes the non-Newtonian flow behaviour.
DOI der Erstveröffentlichung: 10.1039/C7CP04814A
URL der Erstveröffentlichung: https://pubs.rsc.org/en/content/articlelanding/2017/cp/c7cp04814a#!divAbstract
Link zu diesem Datensatz: hdl:20.500.11880/27863
http://dx.doi.org/10.22028/D291-28981
ISSN: 1463-9084
1463-9076
Datum des Eintrags: 24-Sep-2019
Fakultät: NT - Naturwissenschaftlich- Technische Fakultät
Fachrichtung: NT - Chemie
Professur: NT - Prof. Dr. Tobias Kraus
Sammlung:SciDok - Der Wissenschaftsserver der Universität des Saarlandes

Dateien zu diesem Datensatz:
Es gibt keine Dateien zu dieser Ressource.


Alle Ressourcen in diesem Repository sind urheberrechtlich geschützt.