Use of an organosilane coupling agent in colloidal silica coatings

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:427698

Daniels, M W; Chu, L; Francis, L F ^[1]

---

1. Univ. of Minnesota, Minneapolis, MN (United States). Dept. of Chemical Engineering and Materials Science

Coatings were prepared from suspensions containing colloidal silica (20 nm) in isopropanol and 3-glycidoxypropyltrimethoxysilane (GPS). Thicker coatings without cracks were achieved by increased addition of GPS. The microstructure of the resultant coatings contained well packed colloids with some pore space. When high amounts of GPS were added (i.e., GPS:silica weight ratio (R) greater than 0.5), polymeric material appeared and covered the necks between particles and filled in pores. {sup 29}Si NMR of coating suspensions (R = 1) showed GPS hydrolysis within a few minutes and GPS adsorption on the silica surface within a few hours. The excess silane remained in solution and further polymerized, instead of forming a thick multilayer on the colloids. Diffuse reflectance IR spectroscopy data suggests saturated surface coverage beginning around 2 to 3 molecules/nm{sup 2} based on observed depletion of silica surface hydroxyls.

• Sponsoring Organization: National Science Foundation, Washington, DC (United States)
• OSTI ID: 427698
• Report Number(s): CONF-960401--; ISBN 1-55899-338-X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHEMICAL COMPOSITION
COMPOSITE MATERIALS
EPOXIDES
EXPERIMENTAL DATA
FOURIER TRANSFORM SPECTROMETERS
HYDROLYSIS
MICROSTRUCTURE
NUCLEAR MAGNETIC RESONANCE
OPTICAL MICROSCOPY
PHTHALATES
POLYETHYLENES
POLYMERS
POROSITY
SCANNING ELECTRON MICROSCOPY
SILANES
SILICA
SUBSTRATES
SURFACE AREA
SURFACE COATING