Preparation and Characterization of Alumina Thin Film by Sol-Gel Method (II); Synthesis of Alumina Sol for Coating and Preparation of Coating Films

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J. Korean Ceram. Soc. > Volume 31(8); 1994 > Article

Journal of the Korean Ceramic Society 1994;31(8): 911.

졸겔법에 의한 알루미나 박막의 제조 및 특성(II);코팅용 알루미나 졸의 합성 및 박막 제조

이재호, 최세영

연세대학교 세라믹공학과

Preparation and Characterization of Alumina Thin Film by Sol-Gel Method (II); Synthesis of Alumina Sol for Coating and Preparation of Coating Films

ABSTRACT

As the study for preparation of single-layer anti-reflective coating on glass, the conditions of synthesis of sol for coating and of reproducible coating procedure were investigated. In case of water-based sol, coating was impossible because of poor wettability of sol. The Substitution of solvent with ethanol improved the wettability of sol on the glass surface, and optimum amount of ethanol for substitution was 70 vol%. Maximum specific surface area and total pore volume of water-based sol were 268.7$m^2$/g and 0.315 cc/g, but after substitution, those values increased to 404.1 $m^2$/g and 0.376 cc/g, respectively. The upper limit withdrawl speed of coating in order to get clean coated films without aggregations or stains was 7 cm/min. In case of addition of 0.1 mol HNO3 and substitution with 70 vol% ethanol and heat-treatment at 40$0^{circ}C$ for 1 hour, thin film with thickness of 94 nm was obtained at withdrawl speed of 4 cm/min. The thickness of thin film was independent of drying time.