Solvent Effects on Surface Composition of Poly(dimethylsiloxane)-co- polystyrene/Polystyrene Blends
Abstract
The effects of mixed solvents used for casting films of diblock copolymer/homopolymer blends of poly(dimethylsiloxane)-co-polystyrene/polystyrene have been studied in detail at the surface of films. The surface composition was determined over a wide range of detection depths using data from various spectroscopic techniques, including X-ray photoelectron spectroscopy (XPS), attenuated total reflection (ATR) FTIR and time-of-flight secondary ion mass spectrometry (ToF SIMS). After surveying a range of solvents, the surface segregation dependence on solvent composition was investigated for two binary solvent mixtures, namely toluene/chloroform and cyclohexanone/chloroform. 100% surface poly(dimethylsiloxane) (PDMS) coverage has been observed for the polymer blends containing 2% PDMS in bulk using the optimized cyclohexanone/chloroform mixture as solvent. Detectable amounts of polystyrene (PS) residue can be observed on surface for samples cast from other solvents. The PDMS enriched surface region is much thicker for samples cast from cyclohexanone/chloroform solvent mixtures. ToF SIMS analysis results sugges that casting solvents also alter the surface morphology of sample films. The effect of solvent on the surface composition, depth gradient and surface molecular structure of solution cast films are discussed in terms of polymer-solvent interaction parameters and polarity of solvents.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1998
- Accession Number
- ADA351826
Entities
People
- Jiaxing Chen
- Joseph A. Gardella
Organizations
- University at Buffalo