Recently, Professor Du Lin's research group from the Environment Research Institute, published their latest work entitled "Understanding the Interfacial Behavior of Typical Perfluorocarboxylic Acids at Surfactant-Coated Aqueous Interface" in Journal of Geophysical Research: Atmospheres. Professor Du Lin is the corresponding author, and Ph.D. candidate Cheng Shumin is the first author of the article.

From the perspective of marine aerosol interface simulation, artificial seawater and pure water were used as subphases in a Langmuir trough to construct mixed lipid/perfluorocarboxylic acid monolayers with good mechanical properties. In addition,infrared reflection-absorption spectroscopy (IRRAS) technique was used to provide further molecular-level insights into interfacial arrangements of the surface films.Surface pressure (π)−area (A) isotherms of Langmuir monolayers on aqueous surfaces are capable of revealing the underlying phase behavior of the monolayers under constant compression.Alterations in the π−A isotherms upon introduction of perfluorocarboxylic acids indicated variations in surface packing and stability of the monolayers, and the existence of strong molecular interactions between film components. Moreover, changes in characteristic peaks of IRRAS spectra correlated well with those shown by the π−A isotherms.

The organic films exert critical effects on the physical, chemical and optical properties of marine aerosols. Closely packed surface films can weaken the ability of aerosols to uptake H₂O and other trace gases. In a similar way, the films can reduce the evaporation of water from the aerosol, and further enhance the aerosol lifetime. From the molecular area changes in the isotherms, the lipid monolayers generally underwent expansions in the presence of perfluorocarboxylic acids, and the abovementioned physicochemical processes are expected to be greatly accelerated. Meanwhile, incorporation of perfluorocarboxylic acids into organic coatings of marine aerosols provides a potential pathway for their sea-to-air transfer.

In recent years, Professor Du Lin and his research group members have been working on the surface properties of marine aerosols, and have made a series of progresses in this field. Relevant works have been published in well-known environmental journals such as Atmospheric Chemistry and Physics, Environmental Pollution, Science of the Total Environment and Atmospheric Environment.

This research was supported by National Natural Science Foundation of China, Shandong Natural Science Fund for Distinguished Young Scholars, Youth Innovation Program of Universities in Shandong Province, Fundamental Research Fund of Shandong University and the European Union's Horizon 2020 research and innovation programme.

Weblink of the published research:

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019JD032182

Written by: Cheng Shumin

Edited by: Xie Tingting