Journal article
Quantifying Viscosity of Semisolid Submicrometer and Nanosized Individual Aerosols Using Atomic Force Microscopy with Varying Cantilever Velocity
Analytical chemistry (Washington)
10/01/2026
DOI: 10.1021/acs.analchem.6c02398
Abstract
Atmospheric aerosol viscosity governs diffusion time scales of reactive gases into aerosols, thereby influencing gas uptake, heterogeneous chemistry, and atmospheric aging. However, direct viscosity measurements of individual semisolid aerosols have been restricted to a relatively high viscosity range and submicrometer size. Herein, a new atomic force microscopy-based nanorheological experimental approach is presented that utilizes force–indentation distance and indentation rate measurements at varying cantilever velocities to quantify the viscosity of individual semisolid aerosols as a function of relative humidity (RH). Using glucose and sucrose as model systems, we demonstrate accurate single particle viscosity quantification spanning ∼102·5 to 107 Pa s under atmospherically relevant RH conditions. We establish an iterative cantilever velocity framework that enables the determination of the appropriate velocity required for accurate viscosity characterization of aerosols without prior knowledge of their composition. Additionally, we demonstrate that the method enables accurate viscosity quantification of individual sub-100 nm aerosols. We anticipate that future viscosity measurements of atmospheric aerosols from various sources at different RHs will provide valuable insights into aerosol viscosity variability and reveal the extent of particle-to-particle heterogeneity.
Details
- Title: Subtitle
- Quantifying Viscosity of Semisolid Submicrometer and Nanosized Individual Aerosols Using Atomic Force Microscopy with Varying Cantilever Velocity
- Creators
- Ruwini A. Weerasinghe - University of IowaChamika K. Madawala - University of IowaAlexei V. Tivanski - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Analytical chemistry (Washington)
- DOI
- 10.1021/acs.analchem.6c02398
- ISSN
- 0003-2700
- eISSN
- 1520-6882
- Publisher
- American Chemical Society
- Grant note
- U.S. Army DEVCOM, Army Research Office: W911NF2410221
This work was supported by the U.S. Army DEVCOM, Army Research Office under award number W911NF2410221, MURI: Associating Biology and Chemistry to study SUCCession in Environmental SurfaceS (ABCs of SUCCESS).
- Language
- English
- Electronic publication date
- 10/01/2026
- Academic Unit
- Chemistry
- Record Identifier
- 9985243573502771
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