Formation and Characterization of Titania Nanosheet-Precipitated Coatings via Sol-Gel Process with Hot Water Treatment under Vibration
详细信息 查看全文
- 作者：Atsunori Matsuda ; Tatsuo Matoda ; Toshihiro Kogure ; Kiyoharu Tadanaga ; Tsutomu Minami ; and Masahiro Tatsumisago
- 刊名：Chemistry of Materials
- 出版年：2005
- 出版时间：February 22, 2005
- 年：2005
- 卷：17
- 期：4
- 页码：749 - 757
- 全文大小：1189K
- 年卷期：v.17,no.4(February 22, 2005)
- ISSN：1520-5002
文摘
Vibrations were found to affect the nanostructure of titania crystallites formed on SiO2-TiO2 gel coatingsduring hot water treatment. Granular anatase nanocrystals of 30-50 nm in size were formed on thecoatings during hot water treatment without vibration, whereas the shape of the precipitates elongated tobe sheetlike by applying a vibration to the substrate during hot water treatment. The sheetlike crystalsmainly consisted of nanosheets with a spacing of about 0.6 nm, and were identified as a hydrated titania,m(TiO2)·nH2O, with the lepidocrocite-like layered structure. Titania nanosheets were characterized by alarge surface-to-volume ratio, allowing the high photocatalytic reactivity comparable to that of anatasecrystals. In addition, the coatings were highly transparent even after the formation of the nanosheets andthermally stable at around 500 
C. The hydrated titania nanosheet-precipitated coatings maintained anexcellent wettability for water and antifogging properties even after being kept in dark for 2000 h due totheir unique physicochemical properties. Processing temperatures for the coatings preparation are lowerthan 100 C under atmospheric pressure, so that the coatings have a great potential for applications tovarious substrates including organic polymers with poor heat resistance.
C. The hydrated titania nanosheet-precipitated coatings maintained anexcellent wettability for water and antifogging properties even after being kept in dark for 2000 h due totheir unique physicochemical properties. Processing temperatures for the coatings preparation are lowerthan 100 C under atmospheric pressure, so that the coatings have a great potential for applications tovarious substrates including organic polymers with poor heat resistance.