Surface-Chemical and -Morphological Influences on Adhesion and Friction: The Use of High-Throughput, Gradient Approaches
Abstract
Pull-off curve measurements in both humidity-controlled air and under water will be carried out by means of AFM and Hysitron adhesion experiments. Tip geometry will be controlled through use of micron-scale glass beads or conospherical diamond tips. Maximum loads and loading rates will be selected to maintain an elastic response of the materials supporting the gradient films and textures. For the experiments with the Hysitron apparatus, we will follow protocols for quasi-static and dynamic adhesion measurements developed by Wahl and coworkers. Initial experiments would involve the simplest morphological gradients (monodisperse beads in a surface-concentration gradient), and would be followed by the more complex, sandblasted gradients. These gradients are of a kind that have already been fabricated many times in our laboratory and yet the experimental data obtainable with them would, to our knowledge, be absolutely unique and highly suitable for comparison with theory. Chemical gradients would be measured and results compared to the (mostly AFM) literature, prior to adding them to the morphological gradients to detect synergistic behavior. For gradient patterns on silicone elastomers, the elastomer properties can be selected to allow us to explore adhesion hysteresis due to gradient surface effects while the underlying mechanics can be expected to follow JKR behavior. Initial experiments would involve the microtribometer, since it is a relatively straightforward method to minimize surface damage and to obtain quantitative data. In tandem with this, AFM experiments would be carried out, followed by macroscopic measurements, when possible.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 21, 2010
- Accession Number
- ADA530873
Entities
People
- Nicholas D. Spencer