Abstract
Synchrotron X-ray reflectivity (XRR) confirms the formation of a quasi-immobilized layer in thin films of polydimethylsiloxane (PDMS) melts near silica surfaces. This layer (40-60 A°) has a lower density than the bulk value, and its thickness varies slightly with PDMS molecular weight. Formation of this layer is very rapid for PDMS melts with low molecular weights (below entanglement limit for these molecules) but takes 5-10 h for higher molecular weights (close to and above their entanglement value).
Original language | English (US) |
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Pages (from-to) | 878-882 |
Number of pages | 5 |
Journal | Polymer |
Volume | 47 |
Issue number | 3 |
DOIs | |
State | Published - Jan 25 2006 |
Funding
This work was supported by the US National Science Foundation under grant no. DMR-0305494. XRR measurements were performed at beam lines X23B of the National Synchrotron Light Source and the MRCAT of the Advanced Photon Source, which are supported by the US Department of Energy.
Keywords
- Immobilized layer
- PDMS films
- X-ray specular reflectivity
ASJC Scopus subject areas
- Organic Chemistry
- Polymers and Plastics
- Materials Chemistry