• KSBB Journal
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• v.17 no.4
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• pp.345-349
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• 2002

The adsorption of the antimicrobial compounds(AMCs) and their heat-resistance were investigated for the packaging film manufacture, wherein, the antimicrobial compounds were adsorbed on a silica component. The naturally source antimicrobial compounds were produced by methylotropic actinomycetes strains MO-16 and MO-17, extracted with ethylacetate. Antimicrobial compounds adsorbed on water-soluble silica had retained activity against Gram(+) and the Gram(-) bacteria after heat treatment at 150$\^{C}$ for 5min. The benzoic acid showed strong antimicrobial activity to fungi and was stable to heat treatment. The combination of antimicrobial compound plus benzoic acid was synergistic against test strains. Therefore, we estimated that the water-soluble silica is suitable for the packaging film manufacture as a adsorbent of the antimicrobial compounds.

• YAKHAK HOEJI
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• v.49 no.5
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• pp.410-415
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• 2005

To investigate biological activity of noni extracts treated with HCl and trypsin, we measured the antioxidant activity through vitro assay and cellular system. Both water and lipid soluble fraction of noni extracts dose-dependently scav­enged DPPH radical. Superoxide scavenging activity of lipid soluble fraction after treating HCl and trypsin was significantly more potent than those of other fractions in NBT/xanthine oxidase assay, which suggests that antioxidant activity of noni extracts was increased by the treatment with HCl and trypsin. In antioxidant assay using RBL 2H3 cells, water soluble frac­tion of noni extracts had little effect on silica-induced reactive oxygen species generation, whereas lipid soluble fraction inhibited in a dose dependent manner. In non-treated noni extracts, effect of water soluble fraction on silica/$CuSO_4$-induced lipid peroxidation was more potent than that of lipid soluble fraction. However, the effects of noni extracts were reversed in noni extracts treated with HCl and trypsin. These data suggest that water soluble substances may be converted into lipid soluble substances by the treatment with HCl and trypsin. From the above results, it is suggested that lipid soluble fraction of noni extracts contain antioxidant used in vitro assay and RBL 2H3 cellular system. Such an effect of noni extracts may be increased by the treatment with HCl and trypsin.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.295-302
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• 2006

The present study addressed the efficacy of nanosized silica-silver for controlling plant pathogenic microorganisms. The nanosized silica-silver consisted of nano-silver combined with silica molecules and water soluble polymer, prepared by exposing a solution including silver salt, silicate and water soluble polymer to radioactive rays. The nanosized silica-silver showed antifungal activity against the tested phytopathogenic fungi at 3.0 ppm with varied degrees. In contrast, a number of beneficial bacteria or plant pathogenic bacteria were not significantly affected at 10 ppm level but completely inhibited by 100 ppm of nanosized silicasilver. Among the tested plant pathogenic fungi, the new product effectively controlled powdery mildews of pumpkin at 0.3 ppm in both field and greenhouse tests. The pathogens disappeared from the infected leaves 3 days after spray and the plants remained healthy thereafter. Our results suggested that the product developed in this study was effective in controlling various plant fungal diseases.

• Cement Symposium
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• no.20
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• pp.26-30
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• 1992

• Journal of Radiation Industry
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• v.2 no.3
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• pp.149-154
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• 2008

The present study described an antimicrobial spray composition comprising nanosized silica-silver particles, in which nano-silver is bound to silica molecules and a water-soluble polymer, the nanosized silica-silver particles prepared by irradiating a solution comprising a silver salt, silicate and the water-soluble polymer with radiation rays. According to a surfactant addition, the compositions were not turbid and were colorless. Also samples (cotton fabrics and wallpaper) were treated with the compositions also did not cause any stains even after drying under sunshine and at $80^{\circ}C$. Our results suggested that the spray formulation product was of practical use to control indoor fungi.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.257-257
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• 2013

In order to selectively remove oil and organic compound from water, silica nanoparticles with hydrophobic coating was used. Since silica nanoparticles are generally hydrophilic, removal efficiency of oil and organic compound, such as toluene, in water can be decreased due to competitive adsorption with water. In order to increase the removal efficiency of oil and toluene, hydrophobic polydimethylsiloxane (PDMS) was coated on silica nanoparticles in the form of thin film. Hydrophobic property of the PDMS-coated silica nanoparticles and hydrophilic silica nanoparticles were easily confirmed by putting it in the water, hydrophilic particle sinks but hydrophobic particle floats. PDMS coated silica nanoparticles were dispersed on a slide glass with epoxy glue on and the water contact angle on the surface was determined to be over $150^{\circ}$, which is called superhydrophobic. FT-IR spectroscopy was used to check the functional group on silica nanoparticle surface before and after PDMS coating. Then, PDMS coated silica nanoparticles were used to selectively remove oil and toluene from water, respectively. It was demonstrated that PDMS coated nanoaprticles selectively aggregates with oil and toluene in the water and floats in the form of gel and this gel remained floating over 7 days. Furthermore, column filled with hydrophobic PDMS coated silica nanoparticles and hydrophilic porous silica was prepared and tested for simultaneous removal of water-soluble and organic pollutant from water. PDMS coated silica nanoparticles have strong resistibility for water and has affinity for oil and organic compound removal. Therefore PDMS-coated silica nanoparticles can be applied in separating oil or organic solvents from water.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.35-40
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• 1999

For application of a yellow pigment as food additives, stability of a water-soluble yellow pigment from Bacillus sp. PY123 was investigated. The yellow pigment from Bacillus sp. PY123 was purified with pH treatment, activated carbon and silica gel column chromatography. The partial purified yellow pigment appeared only one spot on silica gel TLC after 12 evaporation and under irradiation of UV 253nm at dark room. Rf value of the pigment was measured at 0.04 and 0.12 with development of a solvent mixture (Butanol : Acetic acid : water = 4 :1:5) and a solvent mixture (Isopropanol : Ammonia : Water = 9 :1: 2), respectively, The partial purified pigment appeared a white fluorescence under UV365nm irradiation. The partial purified yellow pigment had a main peak and a minor peak on HPLC using 20mM phosphate buffer(pH 7.0) at 1ml/min flow rate. The partial purified pigment was stable at heat treatment, acidic pH, oxide-reductants and surfactants.

• Korean Journal of Soil Science and Fertilizer
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• v.6 no.4
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• pp.221-226
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• 1973

In order to investigate the silica effect of insufficient wollastonite to the official standard (above than 15% of suluble silica (N/2 HCl) on rice plant as silica fertilizer, 9 kinds of wollastonites and slag were adopted to examine the amount of silica absorbed by rice straw during growing period, and soluble silica of wollastonites extracted by 7 buffer solutions were compared with silica content in rice straw. Crystalls of ingredient in wollastonite ores were identified by X-ray diffractometer. The results were that silica content of rice plant at growing stages were increased as same ratio of soluble silica. content in wollastonite. Wollastonite containing more than 10% of souble silica (N/2 HCl) could be applied as fertilizer because absorbed amount of silica by rice plant from them are higher than from slag which contained 30% of soluble silica. Wollastonite powder mixed with impure ores in which soluble silica could not be extracted had the same effect on silica absorption of straw as wollastonite powder which contained conformable amount of soluble silica. The soluble silica of wollastonite extracted by buffer solutions (2% citric acid, N. NaOAc, N. $NH_4OAc$, Petermann solution, 0.1M. EDTA, and Hot water) had high significant relation to silica content in rice straw, but soluble silica extracted N/2 hydrochloric acid solutilon, also, had deep relation to them in rice straw. The adequate solution to extract silica from wollastonites is N/2 hydrochloric acid solution because its extracted silia amount is much higher than other solution (about one hundred times) and can be determined by gravimetric analysis. X-ray diffraction pattern would identify qualitatively purity of wollastonite, and large amount of soluble silica was extracted from wollastonite which was appeared to be weathered.

• Resources Recycling
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• v.26 no.3
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• pp.53-60
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• 2017

Black dross contains metallic aluminium, alumina, silica, MgO, soluble salts together with minor ingredients. Control of silica in black dross is important in transforming the black dross into usable materials. First, most of the soluble salts (KCl and NaCl) in black dross were dissolved in water at reaction temperature of $50^{\circ}C$. Leaching behavior of silica, alumina, MgO and $TiO_2$ from the residue after water treatment was investigated by varying NaOH concentration and reaction temperature. Reaction temperature ($25{\sim}95^{\circ}C$) was favorable to the leaching of alumina but an optimum temperature existed for silica. MgO was not dissolved at all in the NaOH concentration range from 2 to 6 M. At the leaching condition of 5 M NaOH and reaction temperature of $95^{\circ}C$, approximately 80% of alumina and 68% of silica was dissolved.

• Journal of Powder Materials
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• v.30 no.4
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• pp.305-309
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• 2023

This study aims to prepare a colloidal silica-containing powder to enhance the solubility and dissolution rate of rivaroxaban using a self-nanoemulsifying drug delivery system (SNEDDS). We investigate the impact of colloidal silica on a nanoemulsion system for preparing powdered SNEDDS. The liquid SNEDDS comprises 30/20/50 (w/w/w) Peceol/Cremophor RH40/Tween 80, which results in the formation of the smallest droplets. Three powdered SNEDDS formulations are prepared by suspending the liquid SNEDDS formulation using colloidal silica and spray drying. The powdered SNEDDS prepared with liquid SNEDDS and colloidal silica at a ratio of 1/0.5 (w/w) exhibits the highest water solubility (0.94 ± 0.62 vs. 26.70 ± 1.81 ㎍/mL) and dissolution rate (38.4 ± 3.6 vs. 85.5 ± 3.4%, 45 min) when compared to the drug alone. Morphologically, the liquid SNEDDS is adsorbed onto colloidal silica and forms smaller particles. In conclusion, an SNEDDS containing rivaroxaban, prepared using colloidal silica, facilitates the creation of a nanoemulsion and enhances the water solubility of rivaroxaban. Accordingly, this technology holds significant potential for commercialization.