Nano- and micro-structural surface reorganizations in polymer thin films : a multi-technique investigation
(2006)
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- Authors
- Supervisors
- Bertrand, Patrick
- Abstract
- Surfaces of materials are dynamic regions, which readily rearrange or react, leading to properties different from the bulk. This thesis explores the surface phenomena exhibited by polymer thin films using different surface characterization techniques including ToF-SIMS, NanoSIMS, XPS, AFM, SEM and water contact angle measurements. Thin films of compositionally similar but structurally dissimilar systems like blends and di-block copolymers of polystyrene and poly(methyl methacrylate) exhibited different segregation behaviour in terms of the surface composition on annealing. A realistic portrait of the surface and interfacial behaviour of these thin films was obtained, only on combining the surface morphological and compositional information from the different characterization techniques. The effect of processing parameters like the film thickness, the time and temperature of annealing was investigated. In blends, the increase in film thickness increased the surface domain sizes from "nano" to "micro" range, with the surface composition and morphology remaining similar for the different thicknesses. Copolymer surfaces showed that the surface morphology changed with the film thickness but the surface composition remained the same. An increase in temperature was found to facilitate the phase separation process in blends while in copolymers, it aided the formation of distinct surface morphology. The effect of reactive blending on the surface segregation behaviour in blends was also examined. The studies showed that unless verified by independent techniques, the compositional information may not be able to predict accurately the film morphology and vice versa. Thus, a multi-technique investigation was found necessary for obtaining the complete picture of the surface and interfacial changes undergone by these polymeric thin films.
- Affiliations
Citations
Kailas, L. (2006). Nano- and micro-structural surface reorganizations in polymer thin films : a multi-technique investigation. https://hdl.handle.net/2078.5/97582