Organic–inorganic sol-gel thick films for humidity barriers

Hybrid thick films were deposited on Surlyn, a copolymer of poly(ethylene- co-methacrylic acid) and a common adhesion film for metal surfaces. Hybrid organic–inorganic materials were prepared by a sol-gel process. Methyltriethoxysilane (MTES) with tetraethoxysilane (TEOS), phenyltriethoxysilane (PhTES) with TEOS, and methyltrimethoxysilane (MTMS) with tetramethoxysilane (TMOS) were investigated. The inorganic component was selected to form the network for the film, while the organic component was selected to repel water and fill porosity. The films were deposited on Surlyn and on glass slides. The properties of the films were investigated using attenuated total reflection Fourier transform infrared (FTIR) and Raman spectroscopy. Contact-angle measurements indicated that the contact angle increased from ∼76.5° for Surlyn alone to ∼89.6° for Surlyn coated with MTES.