Issue 11, 2018

Emerging investigator series: exploring the surface properties of aqueous aerosols coated with mixed surfactants

Abstract

Mixed Langmuir monolayers of cholesterol with both saturated and unsaturated fatty acids, stearic acid (SA), and oleic acid (OA) spread at the air–seawater surface were studied. The phase behavior, molecular interaction, and conformational order of the monolayers were investigated by surface pressure–area (π–A) isotherms and infrared reflection-absorption spectroscopy (IRRAS) measurements. The thermodynamic parameters of the mixed films, including excess molecular area and excess Gibbs free energy were calculated by using the isotherm data. The interaction between SA (or OA) and cholesterol varied with the molar fraction of the fatty acids and surface pressure. OA/chol monolayers showed the characteristics of miscibility, but they acted as nonideal systems. Cholesterol has been observed to have a stabilizing effect on OA monolayers. The negative values of the excess Gibbs free energy in the entire composition range demonstrated that mixed OA/chol monolayers were thermodynamically stable. IRRAS spectra showed that mixing with cholesterol changes the ordering of fatty acid monolayers at the air–seawater surface. The findings provide general information regarding the structural changes in the monolayer induced by lateral packing. These results help in the understanding of the mixing behavior of fatty acids and cholesterol and provide insights into the fate of the mixed-monolayer-coated sea salt aerosol in the ocean environment.

Graphical abstract: Emerging investigator series: exploring the surface properties of aqueous aerosols coated with mixed surfactants

Supplementary files

Article information

Article type
Paper
Submitted
09 sen 2018
Accepted
15 okt 2018
First published
16 okt 2018

Environ. Sci.: Processes Impacts, 2018,20, 1500-1511

Emerging investigator series: exploring the surface properties of aqueous aerosols coated with mixed surfactants

J. Li, S. Li, S. Cheng, N. T. Tsona and L. Du, Environ. Sci.: Processes Impacts, 2018, 20, 1500 DOI: 10.1039/C8EM00419F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements