Surface Structural Studies of Methane Sulfonic Acid at Air/Aqueous Solution Interfaces using Vibrational Sum Frequency Spectroscopy
Abstract
Atmospheric gas phase species such as methane sulfonic acid (MSA) are adsorbed and accommodated into atmospheric aqueous-phase aerosols and in some cases MSA is thought to be produced via aerosol surface chemistry. The studies described herein probe the surface molecular structure of MSA at aqueous solution surfaces using surface vibrational sum frequency spectroscopy (VSFS). In the studies presented here, it is shown that MSA partitions at the surface and that the surface MSA has a preferred surface orientation in which the MSA methyl group points away from the liquid surface. The surrounding surface water structure is significantly affected by the adsorption of MSA. Small amounts of MSA at the surface of water enhances the intermolecular hydrogen bonding between interfacial water molecules. Additional VSF studies show that MSA is effectively displaced by sulfuric acid at an aqueous surface. The structural details presented here may have implications for understanding atmospheric aerosol growth properties.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 10, 2000
- Accession Number
- ADA379636
Entities
People
- E. A. Raymond
- Geraldine L. Richmond
- H. C. Allen
Organizations
- University of Oregon