Nano Archive

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

Yang, F and Wornyo, E and Gall, K and King, W. P. (2007) Nanoscale indent formation in shape memory polymers using a heated probe tip. NANOTECHNOLOGY, 18 (28).

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Official URL: http://www.iop.org/EJ/abstract/0957-4484/18/28/285...

Abstract

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 degrees C) and a range of heating durations from 100 mu s 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.

Item Type:Article
Subjects:Material Science > Nanochemistry
Material Science > Nanostructured materials
ID Code:2304
Deposited By:Anuj Seth
Deposited On:18 Dec 2008 16:18
Last Modified:02 Mar 2009 14:22

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