Nanoscale indent formation in shape memory polymers using a heated probe tip

Journal Article (Journal Article)

This paper presents experimental investigation of nanoscale indentation formation in shape memory polymers. The polymers were synthesized by photopolymerizing a tert-butyl acrylate (tBA) monomer with a poly(ethylene glycol dimethacrylate) (PEGDMA) crosslinker. The concentration and the molecular weight of the crosslinker were varied to produce five polymers with tailored properties. Nanoscale indentations were formed on the polymer surfaces by using a heated atomic force microscope (AFM) cantilever at various temperatures near or above the glass transition (between 84 and 215 °C) and a range of heating durations from 100 μs to 8 ms. The images of the indents were obtained with the same probe tip at room temperature. The contact pressure, a measure of transient hardness, was derived from the indentation height data as a function of time and temperature for different polymers. With increasing crosslinker molecular weight and decreasing crosslinker concentration, the contact pressures decreased at a fixed maximum load due to increased crosslink spacing in the polymer system. The results provide insight into the nanoscale response of these novel materials. © IOP Publishing Ltd.

Full Text

Duke Authors

Cited Authors

  • Yang, F; Wornyo, E; Gall, K; King, WP

Published Date

  • July 18, 2007

Published In

Volume / Issue

  • 18 / 28

Electronic International Standard Serial Number (EISSN)

  • 1361-6528

International Standard Serial Number (ISSN)

  • 0957-4484

Digital Object Identifier (DOI)

  • 10.1088/0957-4484/18/28/285302

Citation Source

  • Scopus