Technical Note: New methodology for measuring viscosities in small volumes characteristic of environmental chamber particle samples
Open Access
- 22 January 2013
- journal article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 13 (2), 791-802
- https://doi.org/10.5194/acp-13-791-2013
Abstract
Herein, a method for the determination of viscosities of small sample volumes is introduced, with important implications for the viscosity determination of particle samples from environmental chambers (used to simulate atmospheric conditions). The amount of sample needed is < 1 μl, and the technique is capable of determining viscosities (η) ranging between 10−3 and 103 Pascal seconds (Pa s) in samples that cover a range of chemical properties and with real-time relative humidity and temperature control; hence, the technique should be well-suited for determining the viscosities, under atmospherically relevant conditions, of particles collected from environmental chambers. In this technique, supermicron particles are first deposited on an inert hydrophobic substrate. Then, insoluble beads (~1 μm in diameter) are embedded in the particles. Next, a flow of gas is introduced over the particles, which generates a shear stress on the particle surfaces. The sample responds to this shear stress by generating internal circulations, which are quantified with an optical microscope by monitoring the movement of the beads. The rate of internal circulation is shown to be a function of particle viscosity but independent of the particle material for a wide range of organic and organic-water samples. A calibration curve is constructed from the experimental data that relates the rate of internal circulation to particle viscosity, and this calibration curve is successfully used to predict viscosities in multicomponent organic mixtures.This publication has 66 references indexed in Scilit:
- Comparing the mechanism of water condensation and evaporation in glassy aerosolProceedings of the National Academy of Sciences of the United States of America, 2012
- Particle-Phase Chemistry of Secondary Organic Material: Modeled Compared to Measured O:C and H:C Elemental Ratios Provide ConstraintsEnvironmental Science & Technology, 2011
- Evolution of organic aerosol mass spectra upon heating: implications for OA phase and partitioning behaviorAtmospheric Chemistry and Physics, 2011
- Inhibition of efflorescence in mixed organic–inorganic particles at temperatures less than 250 KPhysical Chemistry Chemical Physics, 2010
- Predicting temperature‐dependence viscosity of vegetable oils from fatty acid compositionJournal of Oil & Fat Industries, 2006
- Low-Molecular-Weight and Oligomeric Components in Secondary Organic Aerosol from the Ozonolysis of Cycloalkenes and α-PineneThe Journal of Physical Chemistry A, 2004
- Measurement of solution viscosity by atomic force microscopyReview of Scientific Instruments, 2001
- Viscosity measurements based on experimental investigations of composite cantilever beam eigenfrequencies in viscous mediaReview of Scientific Instruments, 2000
- Physical properties of liquid edible oilsJournal of Oil & Fat Industries, 1997
- A Theoretical and Experimental Investigation of the Effect of Internal Circulation on the Drag of Spherical Droplets Falling at Terminal Velocity in Liquid MediaIndustrial & Engineering Chemistry Fundamentals, 1975