TexasScholarWorks
    • Login
    • Submit
    View Item 
    •   Repository Home
    • UT Electronic Theses and Dissertations
    • UT Electronic Theses and Dissertations
    • View Item
    • Repository Home
    • UT Electronic Theses and Dissertations
    • UT Electronic Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Pattern formation and evolution in thin polymer films

    View/Open
    Restricted to EID users (2.187Mb)
    Date
    2001-08
    Author
    Masson, Jean-Loup Didier
    Share
     Facebook
     Twitter
     LinkedIn
    Metadata
    Show full item record
    Abstract
    Thin polymer films are important for many technologies. They are used as coatings, adhesives, lubricants and for device technologies, such as polymer based light-emitting diodes. Several concerns arise when processing and using thin polymer films. Properties of thin polymer films (e.g., viscosity, diffusion, glass transition temperature) are different from bulk properties due to finite size effects (e.g., confinement of the chains) and to interfacial interactions (e.g., presence of the free surface and the substrate). Moreover, the stability of the film on the substrate is of concern. Thin polymer films, of thickness h < 100 nm, fabricated on a substrate may rupture under destabilizing forces, such as van der Waals forces. Rupturing exposes the underlying substrate and the exposed regions will grow, provided that the spreading coefficient is negative. This process is known as dewetting. Thus far, two dewetting morphologies have been vii identified but little is understood about their formation and evolution. The first morphology consists of circular holes throughout the film and the second morphology is reminiscent of patterns associated with spinodal decomposition processes. In this research, we investigated four problems. First, we examined fundamental questions related to the formation and evolution of patterns on the substrate. We documented the existence of different dynamic stages of evolution associated with different driving forces for both “conventional” morphologies (circular holes and “spinodal-like”). Second, we discovered a new morphology that occurs in a thin random copolymer film on a silicon substrate. This morphology results from heterogeneous interactions of the chain segments with the substrate. Third, we examined flow processes in thin polymer films (chain dynamics near surfaces). We show that a fingering instability develop spontaneously at the moving liquid front when the film is below a critical thickness that depends on the length of the chains. This behavior is an intrinsic property of entangled polymer liquids and is nonexistent in simple liquids under the same flow conditions. Fourth and finally, based on our understanding of structural instabilities in thin films, we developed an alternate method to measure viscosity as a function of film thickness in these systems.
    Department
    Materials Science and Engineering
    Description
    text
    Subject
    Thin films
    Thin films--Multilayered
    Epitaxy
    URI
    http://hdl.handle.net/2152/10739
    Collections
    • UT Electronic Theses and Dissertations

    University of Texas at Austin Libraries
    • facebook
    • twitter
    • instagram
    • youtube
    • CONTACT US
    • MAPS & DIRECTIONS
    • JOB OPPORTUNITIES
    • UT Austin Home
    • Emergency Information
    • Site Policies
    • Web Accessibility Policy
    • Web Privacy Policy
    • Adobe Reader
    Subscribe to our NewsletterGive to the Libraries

    © The University of Texas at Austin

     

     

    Browse

    Entire RepositoryCommunities & CollectionsDate IssuedAuthorsTitlesSubjectsDepartmentsThis CollectionDate IssuedAuthorsTitlesSubjectsDepartments

    My Account

    Login

    Statistics

    View Usage Statistics

    Information

    About Contact Policies Getting Started Glossary Help FAQs

    University of Texas at Austin Libraries
    • facebook
    • twitter
    • instagram
    • youtube
    • CONTACT US
    • MAPS & DIRECTIONS
    • JOB OPPORTUNITIES
    • UT Austin Home
    • Emergency Information
    • Site Policies
    • Web Accessibility Policy
    • Web Privacy Policy
    • Adobe Reader
    Subscribe to our NewsletterGive to the Libraries

    © The University of Texas at Austin