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Nanoscale Mechanical Properties of Materials Studied by Interfacial Force Microscopy [microform]

出版	Thesis (Ph.D.)--University of Western Ontario, 2004
ISBN	06129690539780612969056
URL	http://books.google.com.hk/books?id=wGQRvwEACAAJ&hl=&source=gbs_api

註釋The interfacial force microscope (IFM) is a novel scanning probe instrument combining high resolution topographic imaging with quantitative nanoindenting capabilities. The IFM relies on self-balancing capacitive-based force sensors. In this thesis, the microfabrication processes for making sensor components are described in detail, as are the methods for assembling, operating and calibrating IFM force sensors. The application of IFM to KevlarRTM fiber/epoxy composites, films of biomedical polyurethane and to films derived from ZDDP, a widely-used engine oil additive, are also presented. The skin and core regions of microtomed poly(p-phenylene terephthalamide) fibres, tradename KevlarRTM49, were imaged and nanoindented with the IFM. The skin was found to have a lower elastic modulus than the core of the fibre. IFM adhesion tests on polyurethane films yielded unexpected force-displacement curve shapes. While instrument limitations and transfer of sample material onto the tip limited data analysis, there were indications that long necks of polymer were being drawn from the sample surface and that these necks of material were undergoing strain-induced transformations. AFM and IFM imaging of tribofilms prepared from zinc dialkyl dithiophosphate and zinc diaryl dithiophosphate (ZDDPs) allowed the identification of distinct topographic regions. IFM f-d curves collected on different features of the films revealed that these features had distinct nanomechanical properties. The indentation moduli of specific features of the tribofilms were determined and correlated with the results of spectromicroscopic studies. Thermal films generated from a commercial ZDDP and annealed at different temperatures were also studied by IFM, and it was found that annealing increased the modulus of the thermal films.