Monolayer to Bilayer Structural Transition in Confined Pyrrolidinium-Based Ionic Liquids.

Autor: Smith AM; †Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom., Lovelock KR; ‡Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom., Gosvami NN; §Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, 220 South 33rd Street, Philadelphia, Pennsylvania 19104, United States., Licence P; ∥School of Chemistry, The University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom., Dolan A; ‡Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom., Welton T; ‡Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom., Perkin S; †Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom.
Jazyk: angličtina
Zdroj: The journal of physical chemistry letters [J Phys Chem Lett] 2013 Feb 07; Vol. 4 (3), pp. 378-82. Date of Electronic Publication: 2013 Jan 11.
DOI: 10.1021/jz301965d
Abstrakt: Ionic liquids can be intricately nanostructured in the bulk and at interfaces resulting from a delicate interplay between interionic and surface forces. Here we report the structuring of a series of dialkylpyrrolidinium-based ionic liquids induced by confinement. The ionic liquids containing cations with shorter alkyl chain substituents form alternating cation-anion monolayer structures on confinement to a thin film, whereas a cation with a longer alkyl chain substituent leads to bilayer formation. The crossover from monolayer to bilayer structure occurs between chain lengths of n = 8 and 10 for these pyrrolidinium-based ionic liquids. The bilayer structure for n = 10 involves full interdigitation of the alkyl chains; this is in contrast with previous observations for imidazolium-based ionic liquids. The results are pertinent to these liquids' application as electrolytes, where the electrolyte is confined inside the pores of a nanoporous electrode, for example, in devices such as supercapacitors or batteries.
Databáze: MEDLINE
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