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2007
Master Thesis
Titel
Quantitative analysis of hybrid SiO2 - PMMA coatings using atomic force microscopy and atomic force acoustic microscopy
Abstract
Thin-films of hybrid material deposited on a glass substrate are examined using Atomic Force Microscopy (AFM) and Atomic Force Acoustic Microscopy (AFAM). The hybrid samples examined are composed of an inorganic part (SiO2) and an organic part Poly (methyl methacrylate) (PMMA). The samples are prepared in different molar proportions of inorganic precursor-tetraethoxysilane to monomer-methyl methacrylate (MMA). Samples are examined using the Solver P47 scanning probe microscope (SPM) (NT-MDT, Moscow, Russia) and the Dimension 3000 Atomic Force Microscope (Digital Instruments/Veeco, Santa Barbara, CA). The hybrid samples are examined qualitatively using tapping-mode AFM; images are obtained using both the instruments. A few particles are observed in the topography images, which appear to protrude out of the surface. These particles can be seen as bright spots in the topography images. Contact-resonance spectroscopy (CRS) is performed in order to confirm the identity of the bright spots appearing. The relation of the contact-resonance frequency and the contact-stiffness is explained, which is important in order to make a quantitative analysis of the hybrid samples to determine the contact-stiffness. The contact-stiffness gives an indication of the overall stiffness of the material. The reference fused silica and the reference PMMA sample are analyzed along with the hybrid samples. It is observed that the contact-stiffness of the hybrid samples is close to that of the reference fused silica sample and contact-stiffness increases with increasing MMA content. The samples with higher molar fraction on MMA are found to be stiffer.
ThesisNote
Zugl.: Saarbrücken, Univ., Master Thesis, 2007
Verlagsort
Saarbrücken