Abstract
Hydrophilic coating solutions were synthesized by adding glycidoxypropyltrimethoxysilane (GPS) to the colloidal silica suspensions adjusted to different pH. The coating solutions were coated on polyethyleneterephthalate (PET) film substrates. The pH of the colloidal silica suspensions adjusted before adding the GPS had a profound effect on chemical structure of the coating solutions and hydrophilic property of the coating films. 29Si NMR spectroscopic studies showed that the solution prepared under an acidic condition (pH 4) consisted of hydrolyzed GPS monomers without siloxane bond and dimer with one siloxane bond, whereas that under a basic condition (pH 9.6) was made up larger oligomers with two or three siloxane bonds. Contact angles for water in the coating films prepared under acidic conditions exhibited smaller than those under basic conditions, indicating more hydrophilic in acidic conditions. In especial, in the case of coating films prepared under highly acidic conditions (pH 1 and 2), the contact angles were less than 5°, which is superhydrophilic.
Original language | English |
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Pages (from-to) | 53-59 |
Number of pages | 7 |
Journal | Journal of Sol-Gel Science and Technology |
Volume | 27 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2003 May |
Keywords
- Contact angles
- Glycidoxypropyltrimethoxysilane
- Hydrophilic
- PH
- Silica particles
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Chemistry(all)
- Biomaterials
- Condensed Matter Physics
- Materials Chemistry