jp9b05220_si_001.txt (15.62 kB)
Compression-Induced Topographic Corrugation of Air/Surfactant/Water Interface: Effect of Nanoparticles Adsorbed beneath the Interface
dataset
posted on 2019-10-10, 14:04 authored by Inseok Chae, Dien Ngo, Mohamadamin Makarem, Zoubeida Ounaies, Seong H. KimThe compression isotherm
of a Langmuir film can provide information
on the structural order and density of interfacial molecules. When
nanoparticles are introduced to the Langmuir film at an air/liquid
interface, the compression isotherm is altered substantially. In this
study, we report experimental evidence of topographic corrugation
of the air/surfactant/water interface due to compression of nanoparticles
adsorbed underneath the surfactant layer. A monolayer of cationic
surfactants is suspended in a Langmuir trough with negatively charged
nanoparticles in the aqueous subsurface. Changes in structural orders
of the interfacial molecules and nanoparticles were characterized
using in situ sum-frequency generation (SFG) spectroscopy during compression
and associated with the modified compression isotherm in the presence
of nanoparticles. This work elucidated changes in the compression
isotherm due to the variation of surface geometry, which is required
to produce a desired Langmuir film made of nanoparticles.