skip to main content

This content will become publicly available on February 20, 2016

Title: Interfacial binding of divalent cations to calixarene-based Langmuir monolayers

The interactions of Langmuir monolayers produced through the self-assembly of an amphiphilic p-carboxycalix[4]arene with a series of divalent, fourth-period transition metals, at the air-water interface, were investigated. Changes in the interfacial behavior of 1 in response to the presence of CuCl2, CoCl2, MnCl2, and NiCl2 were studied by means of Langmuir compression isotherms and Brewster angle microscopy (BAM). The measurements revealed that the self-assembly properties of 1 are significantly affected by Cu2+ ions. The interactions of 1-based monolayers with Co2+ and Cu2+ ions were further investigated by means of synchrotron radiation-based X-ray reflectivity (XRR), X-ray near-total-reflection fluorescence (XNTRF), and grazing incidence X-ray diffraction (GIXD). XNTRF and XRR analyses revealed that the monolayer of 1 binds more strongly to Cu2+ than Co2+ ions. In the presence of relatively high concentrations of Cu2+ ions in the subphase (1.4 × 10-3 M), XNTRF exhibited anomalous depth profile behavior and GIXD measurements showed considerably strong diffuse scattering. Furthermore, both measurements suggest the formation of Cu2+ clusters contiguous to the monolayer of 1.
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [4] ;  [2] ;  [1]
  1. Univ. of Applied Science and Arts Northwestern Switzerland, Muttenz (Switzerland)
  2. Ames Lab. and Iowa State Univ., Ames, IA (United States)
  3. Argonne National Lab. (ANL), Lemont, IL (United States)
  4. Univ. of Basel, Basel (Switzerland)
Publication Date:
OSTI Identifier:
1253372
Report Number(s):
IS-J-9001
Journal ID: ISSN 0743-7463
Grant/Contract Number:
AC02-07CH11358; 200020_143592
Type:
Accepted Manuscript
Journal Name:
Langmuir
Additional Journal Information:
Journal Volume: 31; Journal Issue: 8; Journal ID: ISSN 0743-7463
Publisher:
American Chemical Society
Research Org:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; calix[4]arenes; Langmuir monolayers; self-assembly; X-ray near-total-reflection fluorescence; grazing incidence X-ray diffraction