Growth of Mesoporous Silica Films on Hydrophilic or Hydrophobic Surfaces.

Sugimura, Hiroyuki; Hozumi, Atsushi; Ushiyama, Kazuya; Takai, Osamu; Okido, Masazumi

doi:10.4139/sfj.50.574

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ODS−SAM's thickness as estimated by ellipsometry was 1.9 ± 0.1 nm and its surface was hydrophobic, showing a water contact angle of about 106°. We have grown a composite on such a surface as a continuous thin film . Details of our CVD method have been described elsewhere …”

Section: Methodsmentioning

confidence: 99%

Low-Temperature Elimination of Organic Components from Mesostructured Organic−Inorganic Composite Films Using Vacuum Ultraviolet Light

et al. 2000

Self Cite

View full text Add to dashboard Cite

A novel and simple procedure named photocalcination has been developed for removing organic components from mesostructured organic−inorganic composite films. This procedure employs an excimer lamp radiating vacuum ultraviolet (VUV) light of 172 nm in wavelength. Organic molecules are removed through two distinct photochemical reactions proceeding simultaneously at room temperature: the photocleavage of C−H and C−C bonds in the organic molecules by direct photoexcitation and their subsequent oxidation with activated oxygen species generated by the photoexcitation of atmospheric oxygen molecules. In this study, a composite of cetyltrimethylammonium chloride−silica (CTAC−silica) was used. Thin films of this organic−inorganic composite were prepared on Si substrates coated with a self-assembled monolayer of octadecyltrimethoxysilane. The films were irradiated with VUV light under pressures of 10, 102, 103, or 105 Pa. Although, in each case, the CTAC molecules in the composite films were completely oxidized and removed, the elimination rate increased with an increase in the photocalcination pressure. While 3 h of irradiation was necessary to completely remove the CTAC molecules at 10 Pa, only 0.5 h was required at 105 Pa. However, the periodic mesostructures of the film photocalcined at 105 Pa distorted significantly because of the rapid photooxidation. As a control experiment, identical CTAC−silica mesocomposite films were calcined thermally. The films were heated in air at temperatures from 373 to 773 K. Although the CTAC molecules could be eliminated completely at temperatures higher than 573 K, the periodic mesostructures of the thermocalcined films were much more distorted than those of the photocalcined films.

show abstract

Section: Methodsmentioning

confidence: 99%