Surface structure of a "non-amphiphilic" protic ionic liquid
2012 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 14, no 15, 5106-5114 p.Article in journal (Refereed) Published
The nanostructure of the ethanolammonium nitrate (EtAN)-air surface has been investigated using X-ray reflectometry (XRR), vibrational sum frequency spectroscopy (VSFS) and neutral impact collision ion scattering spectroscopy (NICISS). The XRR data decays more rapidly than expected for a perfectly sharp interface, indicating a diffuse electron (scattering length) density profile. Modelling of the XRR data using three different fitting routines produced consistent interfacial profiles that suggest the formation of interfacial EtAN clusters. Consistent with this, VSFS reveals that the EtAN surface is predominantly covered by -CH2- moieties, with the -NH3+ and -OH groups of the cation buried slightly deeper in the interface. The elemental profiles determined using NICISS also show enrichment of carbon relative to nitrogen and oxygen in the outermost surface layer, which is consistent with the surface cation orientation deduced from VSFS, and with the presence of EtAN aggregates at the liquid surface.
Place, publisher, year, edition, pages
2012. Vol. 14, no 15, 5106-5114 p.
Chemical Sciences Physical Sciences
IdentifiersURN: urn:nbn:se:kth:diva-93662DOI: 10.1039/c2cp23694jISI: 000301957900010ScopusID: 2-s2.0-84858982947OAI: oai:DiVA.org:kth-93662DiVA: diva2:523797
FunderSwedish Research Council
QC 201204262012-04-262012-04-232012-04-26Bibliographically approved