Type
Text
Type
Thesis
Advisor
Koga, Tadanori | Sokolov, Jonathan | Kim, Taejin.
Date
2016-12-01
Keywords
adhesion, flattened layer, interface, nanothin film, polymer
Department
Department of Materials Science and Engineering
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76232
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Interpenetrations (or entanglements) between chemically identical polymers are important parameters in fundamental physics and industrial applications. However, little is known about the interaction between free polymer chains and chemically identical, but otherwise highly adsorbed chains on solid surfaces. Here we report an unusual interaction between free chains and chemically identical flattened chains which have many surface-segmental contacts with solids. Based on the mechanical adhesion measurements, we found the 2.5 nm-thick equilibrium polyethylene-oxide (PEO) flattened layer show no adhesion with the PEO melts even at T >Tm. Liquid contact angle measurements further revealed that the flattened layer has the same macroscopic surface tension compared to thin films. Hence, the unusual interaction between free chains and highly adsorbed flattened chains is not due to a difference in the surface tension, but is associated with the unique chain conformation of flattened chains which cannot form sufficient entanglements with free chains in the melt. Since the formation of flattened chains is rather general, the presented experimental findings not only shed new light on the interfacial interaction between free chains and flattened chains near the solids, but also provide a simple and effective way to control and manipulate the adhesive properties and crystallization behaviors of thin polymer films prepared on solid surfaces. On the other hand, the "loosely adsorbed" polymer chains, which are formed as a result of limited adsorption space on the solid surface, do display a degree of adhesion with the bulk polymer. We postulate that the loosely adsorbed chains act as "connectors" which promote adhesion effectively across the solid-polymer interface, while the "flattened" chains are so densely compact on the substrate that the outer free chains cannot penetrate into it to form adhesion. | 43 pages
Recommended Citation
Chen, Zhizhao, "Novel adhesion properties of irreversibly adsorbed polymer chains" (2016). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2168.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2168