Investigations of heterogeneous ultrathin blends using lateral force microscopy
Year: 2001
Authors: Buenviaje C., Dinelli F., Overney R.M.
Autors Affiliation: Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA.
Abstract: In order to study the glass transition of thin film polymer blends, high spatial resolution and temperature sensitivity is needed. In this paper, we emphasize the importance of the calibration of scanning parameters such as load and speed when measuring the glass transition temperature of polymers using lateral force microscopy. Once calibrated, this method is ideal for investigations of heterogeneous samples such as blends and co-polymers. We present an analysis technique for lateral force imaging using a fast and stable cooling/heating stage. This approach involves mapping the friction forces over a certain area and identifying regions of different frictional properties. The difference in the average friction force can then be plotted as a function of temperature. The friction force is expected to vary around the glass transition. Therefore, the glass transition temperature can be defined as the temperature at which the difference in the average friction force undergoes a slope change. We present investigations of blends using polystyrene mixed with poly(butylmethacrylate). The transition temperatures obtained are in good agreement with the bulk values of corresponding homopolymeric films.
Journal/Review: MACROMOLECULAR SYMPOSIA
Volume: 167 Pages from: 201 to: 212
KeyWords: Polymer-films; Glass; Transitions; Dependence; Friction; SurfacesDOI: