• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.41-46
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• 2014

The property improvement of polycarbonate coated with a multilayer film composed of an inorganic $SiO_2$ film and a photocatalytic $TiO_2$ film was studied. The $SiO_2$ film as a binder had an excellent light transmission characteristic. After the treatment with atmospheric pressure plasma, the surface of $SiO_2$ film showed the hydrophilicity, which increased the film coating uniformity with a $TiO_2$-containing aqueous solution. When $TiO_2$ film was over 200 nm thick, the absorption effect of UV rays in the range of 180~400 nm suppressed the yellowing phenomena of polycarbonate substrate. The inorganic film improved the heat resistance of polycarbonate substrates. $TiO_2$ film in the outmost under the exposure of UV rays promotes the catalytic oxidation characteristics and yields the capability to the decomposition of organic contaminants, and also increases the self-cleaning properties due to the increase of hydrophilicity. Structural stability of the polycarbonate substrate coated with inorganic $TiO_2$ and $SiO_2$ film was shown. The role of $SiO_2$ film between $TiO_2$ and polycarbonate substrate suppressed the peeling of $TiO_2$ film by inhibiting the photocatalytic oxidation effect of $TiO_2$ film on the polycarbonate substrate.

• Journal of dental hygiene science
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• v.15 no.5
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• pp.569-576
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• 2015

The aim of this study was to assess the oral health knowledge, attitude and behavior among geriatric care workers in long-term care facilities. A self-administered questionnaire was obtained from 212 geriatric care workers attending a professional education program of 2014 dementia pilot project. The questionnaire consisted of 4 parts of the training experience (2 items), knowledge (16 items), attitude (13 items), and behavior (4 items) on oral health care. Collected data were analyzed by frequency analysis, independent t-test, and one-way ANOVA using SPSS Statistics ver. 20.0. The percentage of educational experience on oral care was 27.9% and most respondents answered that they have received the education about denture cleaning (98.3%) and brushing method (91.4%). The average knowledge score was $10.88{\pm}1.70$, and respondents showed high-level agreement in 8 of the 10 items in attitude questions. They revealed difficulties in providing oral care to the elderly people because of their lack of knowledge. The deficiencies of knowledge about oral care would have a decisive effect on not only oral and general health, but also quality of life of the elderly people. Therefore, it is required to develop professional oral care training programs for geriatric care workers and support systems should be legalized.

• Journal of Adhesion and Interface
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• v.21 no.4
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• pp.143-155
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• 2020

Hydrophobic Organic-Inorganic (O-I) hybrid materials prepared by sol-gel process have been widely used at functional coating fields such as coatings for anti-corrosion, anti-icing, self-cleaning, anti-reflection. The key point for fabricating hydrophobic surface is to optimize the surface energy and roughness of the coating films. There are typical processes to control the surface energy and roughness which are 'In situ fabricating', 'Pre-fluorinating/Post-roughening', 'Pre-roughening/ Post-fluorinating'. In this study, particle-binder process was used for in-situ fabrication of hydrophobic coating films. Various O-I hybrid compounds prepared using several kinds of alkoxysilane compounds were used as a binder for silica nanoparticles at particle-binder process. To study effect of fluorine content and weight ratio of particle : binder on the hydrophobicity and surface morphology, Hydrophobic coating films were prepared onto glass substrate at various content of fluorine content of O-I hybrid binder and weight ratio of particle : binder. The coating films prepared using O-I hybrid binder (GPTi-HF10) having 10 wt% of fluorine content showed the highes water contact angle (107.52±1.6°). The coating films prepared at 1:3 weight ratio of GPTi-HF10 : silica nanoparticle exhibited the highest water contact angle (130.84±1.99°).