Publication date: 30 November 2017
Source:Thin Solid Films, Volume 642
Author(s): Masanari Hirahara, Yasushi Umemura
A solution of the water-insoluble quaternary alkylammonium salt with the long hydrocarbon chain, CH3 (CH2 )29 N(CH3 )3 ·I (C30 TMA+·I−), was spread on water and clay mineral (montmorillonite) dispersion surfaces to investigate film formation behavior of the amphiphilic ammonium cation by π-A isotherm curve measurements, AFM observation, IR spectroscopy, and XRD measurements. The C30 TMA+ cations formed a stable Langmuir film on the water surface. The Langmuir films were deposited on a substrate to fabricate the multilayer, in which the cations stood nearly perpendicularly to the substrate with the all-trans conformation and they were packed closely with two-dimensional ordering. The negatively charged clay-mineral-layers were adsorbed on a floating Langmuir film of the cation at an air-clay mineral dispersion interface. On the dilute clay mineral dispersion surface, some parts of the floating film of the cation were adsorbed by the clay-mineral-layers and the C30 TMA+ cations stood on the clay-mineral-layers. As the clay mineral concentration in the dispersion increased, the π-A isotherm curve for the C30 TMA+ cation at the air-dispersion interface shifted to the larger molecular area side with high collapse pressures (40–50
Source:Thin Solid Films, Volume 642
Author(s): Masanari Hirahara, Yasushi Umemura