Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Characterization of Heterogeneous Regions in Polymer Systems Using Tapping Mode and Force Mode Atomic Force Microscopy



R Raghavan, Mark R. VanLandingham, Xiaohong Gu, Tinh Nguyen


Characterization of polymer coating surfaces is crucial to understanding and predicting the long-term performance of coatings in aggressive environments. The exposed polymer surface and near-surface regions can differ from the bulk polymer film both chemically and mechanically, which can effect the durability of the coating and its ability to protect the underlying substrate. In this study, atomic force microscopy (AFM) is used to investigate the heterogeneity of blended films of poly (methylmethacrylate) (PMMA) and polybutadiene (PB) on silicon substrates before and after annealing. The blended films with different ratios of PMMA to PB are prepared by spin casting onto silicon substrates from solution. The surface morphology and composition of these cast films are investigated using tapping mode and force mode AFM. Annealing the samples in air at 75 C + 5 C causes changes in the relative chemical and mechanical differences between PMMA and PB, so the phase image contrast is studied as a function of annealing time. The effect of tapping force level on phase image contrast is also explored. To identify the different components in polymer blends and to understand the influence of relative surface stiffness on the phase images, nanoscale indentation measurements
No. 24


blends, chemical properties, coatings, mechanical properties, microstructure, nanoindentation, phase contrast


Raghavan, R. , VanLandingham, M. , Gu, X. and Nguyen, T. (2000), Characterization of Heterogeneous Regions in Polymer Systems Using Tapping Mode and Force Mode Atomic Force Microscopy, Langmuir, [online], (Accessed July 16, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created October 31, 2000, Updated October 12, 2021