• Title, Summary, Keyword: Silicate

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A Development of Fire Protective Coating Based on Soluble Alkali Silicate (알칼리 규산염 내화 피복제의 개발)

  • 이내우;김종래;김정훈
    • Journal of the Korean Society of Safety
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    • v.8 no.2
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    • pp.30-38
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    • 1993
  • To increase fire proofing characteristics of protective coating based on soluble alkali silicate, silicate coatings were studied on thermal properties, IR spectroscopy, solubility and intumescence. Intumescence and solubility of the samples were dependent on the strength of cationic cross-links between polysilicate particles. The degree of intumescence and solubility decrease K-silicate > Na-silicate > Li-silicate in the order. Especially Si$_2$O$_{5}$ $^{-2}$ crystalline regions were found to exist in Potassium silicate sample. Mixture of two kinds of silicate, for example, Lithium silicate when added to sodium silicate or potassium silicate was find to significantly reduce efflorescence and increase water resistance. This appears to be a result of stronger crosslinking between polysilicate particles by the small lithium cation.

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Long-term Application Effect of Silicate Fertilizer on Soil Silicate Storage and Rice Yield

  • Kim, Myung-Sook;Park, Seong-Jin;Lee, Chang-Hoon;Ko, Byong-Gu;Yun, Sun-Gang
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.6
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    • pp.819-825
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    • 2016
  • Monitoring of soil fertility and crop productivity in long-term application of silicate fertilizers is necessary to use fertilizers efficiently. This study was conducted to investigate effects of continuous application of silicate fertilizer for rice cultivation from 1969 to 2014. The treatments were no silicate fertilizer treatments (N, NC, NPK, and NPKC) and silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S). The 46-yr input of $2\;ton\;ha^{-1}yr^{-1}$ of silicate fertilizer increased pH 0.6 ~ 1.1 and exchangeable Ca $2.0{\sim}2.4cmol_c\;kg^{-1}$ in silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S) compared with no silicate fertilizer treatments (N, NC, NPK, and NPKC) because silicate fertilizer included Ca component. Also, available silicate concentrations of silicate fertilizer treatments (N+S, NC+S, NPK+S, and NPKC+S) increased $169mg\;kg^{-1}$ compared to no silicate fertilizer treatments. In Period II ('90~'14), the mean annual Si field balance varied from 62 to $175kg\;ha^{-1}yr^{-1}$ in silicate fertilizer treatments, indicating continuous accumulation of soil Si. Silicon uptake and grain yield of rice had greater differences between N treatment and N+S treatment than other treatments. This showed that the application of silicate fertilizer had greater effect in nutrient-poor soils than in proper nutrient soils. Thus the application of silicate fertilizer led to improvement the fertility of soil and increasement of rice production for the lack of soil nutrients.

Stability of Sputtered Hf-Silicate Films in Poly Si/Hf-Silicate Gate Stack Under the Chemical Vapor Deposition of Poly Si and by Annealing

  • Kang, Sung-Kwan;Sinclair, Robert;Ko, Dae-Hong
    • Journal of the Korean Ceramic Society
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    • v.41 no.9
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    • pp.637-641
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    • 2004
  • We investigated the effects of SiH$_4$ gas on the surface of Hf-silicate films during the deposition of polycrystalline (poly) Si films and the thermal stability of sputtered Hf-silicate films in poly Si/Hf-silicate structure by using High Resolution Transmission Electron Microscopy (HR-TEM) and X-ray Photoelectron Spectroscopy (XPS). Hf-silicate films were deposited by using DC-mag-netron sputtering with Hf target and Si target and poly Si films were deposited at 600$^{\circ}C$ by using Low Pressure Chemical Vapor Deposition (LPCVD) with SiH$_4$ gas. After poly Si film deposition at 600$^{\circ}C$, Hf silicide layer was observed between poly Si and Hf-silicate films due to the reaction between active SiH$_4$ gas and Hf-silicate films. After annealing at 900$^{\circ}C$, Hf silicide, formed during the deposition of poly Si, changed to Hf-silicate and the phase separation of the silicate was not observed. In addition, the Hf-silicate films remain amorphous phase.

A Study on the Engineering Properties of Micro Fine Hybrid Silicate Based Grout (마이크로 복합실리카 그라우트의 공학적 특성에 관한 연구)

  • 천병식;김진춘;최영철;정종주;신상재;이홍재
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.63-70
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    • 2000
  • In 1925, H.J. Joosten was the first in the world to use chemical injection grouts composed of sodium silicate and calcium chloride. This unique development prompted the introduction of other chemical grouting techniques. Among these chemical grouting techniques, sodium silicate based grout has been the most widely used in the world, but it has not been generally considered to be a permanent material. Therefore, studies to improve the weak points of sodium silicate based grout have been conducted, and new applications of grout were recently developed. We also developed the micro fine hybrid silicate grout of suspention type which properties are sepecialized as the high strength and durability, according to the reactant of special sodium silicate grout and the high strength hardener. As the results of this study we could derive the 2 times over high strength of Micro fine hybrid Silicate grouting method(MS method) more than that of the ordinary sodium silicate grout. And also we could confirm that the alkali leakage of micro fine hybrid silicate grout is less than that of ordinary sodium silicate grout. So we could get the high strength and durability of hybrid silicate grout are superior to those of ordinary sodium silicate grout.

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Self Cleaning Hydrophilic Impregnant of Concrete Structure (자기세정 콘크리트 표면보호재 적용에 관한 연구)

  • Song, Hun;Kim, Young-Yup;Chu, Yong-Sik;Lee, Jong-Kyu
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.645-648
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    • 2006
  • Normally, deterioration in the concrete structure is due to carbonation and chloride ion attack. Therefore, concrete structure is needed to surface protection for increase durability using impregnant. Impregnant classify into two large groups in polymeric and silicate materials. Silicate impregnant is included silicate and alkali silicate(sodium and lithium silicate). Thus, this study is concerned with self cleaning hydrophilic property of concrete structure using silicate impregnant. From the experimental test result, TEOS and lithium silicate make good use of hydrophilic impregnant.

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Poly(n-butyl acrylate-co-methyl methacrylate) and Poly(n-butyl acrylate-co-styrene)/Silicate Nanocomposites Prepared by Emulsion Polymerization

  • Park, Yeong-Suk;Chung, In-Jae
    • Macromolecular Research
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    • v.11 no.6
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    • pp.425-430
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    • 2003
  • Two types of poly(n-butyl acrylate) copolymer/silicate nanocomposites have been produced: poly(n-butyl acrylate-co-methyl methacrylate) [P(BA-co-MMA)]/silicate nanocomposites and poly(n-butyl acrylate-co-styrene) [P(BA-co-ST)]/silicate nanocomposites. The P(BA-co-MMA)/silicate nanocomposites shows the exfoliated structures but a P(BA-co-ST)/silicate nanocomposites have intercalated structures, because the BA/MMA comonomer has a higher polarity (e-value in Q-e scheme) than the BA/ST comonomer. The BA/MMA comonomer expanded the interlayer space of the silicate wider than did the BA/ST comonomer. The thermal degradation onset point of the P(BA-co-MMA)/silicate nanocomposites was 43$^{\circ}C$ higher than that of pure P(BA-co-MMA). P(BA-co-MMA)T5%, P(BA-co-MMA)T10%, and P(BA-co-MMA)T20% exhibit 134,302, and 195% increases, respectively, in their storage moduli at -20$^{\circ}C$ relative to the pure copolymer.

Preparation and Surface Properties of Polysulfone/Organophilic Layered Silicate Nanocomposites (폴리설폰/친유기화 층상실리케이트 나노복합체의 제조 및 표면 특성)

  • Sul, Kyung-Il;Ma, Seung Lac;Kim, Yong Seok;Lee, Jae Heung;Won, Jong Chan
    • Journal of Adhesion and Interface
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    • v.4 no.4
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    • pp.15-21
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    • 2003
  • Polysulfone/organophilic layered silicate nanocomposites were prepared in the range of 0.25 to 9 wt% of organophilic-layered silicate by solution blend. Nano-hybridized films were cast from the blend solution. Exfoliation and intercalation of the polysulfone/organophiliclayered silicate nanocomposite films were confirmed by an X-ray diffractometer and a transmission electron microscope. Surface morphologies of polysulfone/organophilic layered silicate nanocomposite films were determined by a scanning electronic microscope and an atomic force microscope. When the organophilic layered silicate was added more than 1.5 wt%, the surface roughness (RMS) was rapidly increased because clusters of intercalated organophilic layered silicate particles existed on the polysulfone/organophilic-layered silicate film surface. Surface tension revealed an upward tendency over the contents of 1.5 wt% organophilic layered silicate in polysulfone/organophilic layered silicate nanocomposite. The change of surface morphology in polysulfone/organophilic layered silicate nanocomposite were affected by nano scale dispersed and intercalated organophilic layered silicate particles.

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Property of Concrete Surface layer Using Self-Cleaning Silicate Concrete Impregnant (Self-Cleaning 실리케이트계 표면보호제를 적용한 콘크리트 표층부의 특성)

  • Song, Hun;Lee, Jong-Kyu;Chu, Yong-Sik
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.1 no.3
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    • pp.233-239
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    • 2013
  • This study is interested in manufacturing the self-cleaning silicate concrete surface impregnant including tetra ethyl ortho silicate, lithium silicate for the repair of the exposed concrete surface and the color concrete requiring the advanced function in view of the concrete appearance. The concrete surface layer change and static contact angel was tested for the review of application. The result of this study shows that the effective silicate is tetra ethyl ortho silicate and lithium silicate. The adhesion in tension is satisfied with performance requirement of KS standard but the reinforcement of concrete substrate is slight. So, The self-cleaning silicate concrete impregnant of this study is more desirable for the improvement of durability rather than the reinforcement.

The Study of Hafnium silicate by Nitrogen Annealing Treatment (질소 처리를 통한 Hafnium silicate 박막의 특성 평가)

  • Suh, Dong-Chan;Cho, Young-Dae;Ko, Dae-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.116-116
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    • 2007
  • We investigated the characteristics of the Hafnium silicate (Hf-silicate) film which is grown by ALD (atomic layer deposition). The Hf-silicate films that were annealed by the RTP. The physical and electrical properties of nitrided Hf-silicate films, incorporated by NO gas and $NH_3$ gas annealing, were investigated by XPS, TEM and I-V measurement. We confirmed the nitrogen incorporation during NO gas annealing treatment effectively enhances the thermal stability of Hf-silicate. The tendency of nitnitridation in NO gas and $NH_3$ is different. Leakage current is improved in post NO gas annealing.

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Microstructure and Phase Stability of $\beta$-Dicalcium Silicate ($\beta$형 Dicalcium Silicate 광물의 상 안정성 및 미세구조변화)

  • 박춘근
    • Journal of the Korean Ceramic Society
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    • v.34 no.9
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    • pp.957-962
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    • 1997
  • Dicalcium silicate has many polymorphs according to temperature. $\beta$-dicalcium silicate which exists in cement is stabilized by minor components drived from raw materials regardless of temperature, such as high temperature and room temperature. K2O, SO3 and B2O3 are effective stabilizers for $\beta$-dicalcium silicate at room temperature. B2O3 was the most effective stabilizer. Transformation from $\beta$ to ${\gamma}$ phase causes dicalcium silicate to change volume, resulting in dusting phenomenon. When B2O3 was used the phase transformation is the least than any other stabilizers. In addition, the starting temperature of quenching influences phases transformation : low temperature of quenching presented much phase transformation and decreased size of parameter of $\beta$-dicalcium silicate.

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