<title>Vibrational sum frequency spectroscopy of surfactants and phospholipid monolayers at liquid-liquid interfaces</title>

Alkyl Chain Ordering of Asymmetric Phosphatidylcholines Adsorbed at a Liquid−Liquid Interface

“…It is likely that these changes in temperature indirectly disrupt the interfacial layer and prevent formation of a well-ordered DSPC layer in those studies. Excluding DLPC, which is above T m at room temperature, interfacial adsorption below T m using the technique described in this work has been shown to result in more ordered layers than those produced on adsorption above T m . The 55 Å 2 per PC molecule estimated from surface pressure measurements by Walker et al for adsorption at the CCl 4 −water interface above T m also indicates that, despite the high final surface pressures obtained in these measurements that would otherwise indicate formation of a close-packed monolayer, the PCs may be in either a liquid-expanded or phase coexistence region of the isotherm .…”

“…Excluding DLPC, which is above T m at room temperature, interfacial adsorption below T m using the technique described in this work has been shown to result in more ordered layers than those produced on adsorption above T m . 29 The 55 Å 2 per PC molecule estimated from surface pressure measurements by Walker et al 24 for adsorption at the CCl 4 -water interface above T m also indicates that, despite the high final surface pressures obtained in these measurements that would otherwise indicate formation of a close-packed monolayer, the PCs may be in either a liquidexpanded or phase coexistence region of the isotherm. 30 The results are consistent with electrochemical measurements reported by Kakiuchi et al 31,32 for symmetric chain PCs adsorbed from nitrobenzene to the polarized nitrobenzene-water interface.…”

Modeling Kinetics of Subcellular Disposition of Chemicals

“…Structure and dynamics of liquid−liquid interfaces is a matter of intense experimental research relying mainly on voltammetry, vibrational sum frequency spectroscopy, – and X-ray reflectance, – as well as on computational simulations. ,– The interface structures are rather different, even for similar organic solvents. For lower alkanes and carbon tetrachloride systems, where the nonpolar phase has no hydrated groups interacting with water, the interface is only a few angstroms wide and exhibits molecular sharpness, with a slight mutual permeation of both solvents due to thermally excited capillary waves.…”

Alkyl Chain Ordering of Asymmetric Phosphatidyicholines Adsorbed at a Liquid-Liquid Interface

“…The slight decrease in chain ordering with increasing chain length was attributed to enhanced solvation of the longer acyl chains by CCI4 (Walker et al, submitted). Excluding DLPC which is above T m at room temperature, monolayer adsorption below T m using the technique described has been shown to result in more ordered monolayers than those produced on adsorption above T m (Smiley, et al, 1998). It is possible that CCI4 is not able to penetrate between the hydrocarbon chains of the gel-state phospholipid during room temperature adsorption.…”