Quantitative contact resonance force microscopy for viscoelastic measurement of soft materials in liquid

Published

October 1, 2015

Author(s)

Allison B. Churnside, Ryan C. Tung, Jason P. Killgore

Abstract

Viscoelastic property measurements made in liquid are key to characterizing materials for a variety of biological and industrial applications, but obtaining reliable data with nanoscale spatial resolution is challenging. Contact resonance force microscopy (CR-FM) is an atomic force microscope-based technique for quantitatively determining nanoscale mechanical properties. However, CR-FM in liquid is complicated by difficulty in separating changes in cantilever behavior due to the material from those due to the liquid. By reconstructing the hydrodynamic function to account for surface-coupled fluid effects, we measured the loss tangent (tan δ) using CR-FM. Specifically, we compared the tan δ of polystyrene and polypropylene measured in air and water. Without correcting for the fluid effects, the values for tan δ measured in water were greatly overestimated compared to those measured in air. After applying the hydrodynamic correction, agreement with the values in air improved significantly. This demonstrates the utility of the hydrodynamic reconstruction technique for quantitative, viscoelastic CR-FM measurements on polymers in liquids.

Citation

ACS Macro Letters

Pub Type

Journals

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Keywords

atomic force microscope, contact resonance, loss tangent, polystyrene, polypropylene, liquid environment

Citation

Churnside, A. , Tung, R. and Killgore, J. (2015), Quantitative contact resonance force microscopy for viscoelastic measurement of soft materials in liquid, ACS Macro Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=918555 (Accessed November 19, 2024)