• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.111-111
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• 2012

나노테크놀로지는 종래의 가공으로는 얻기 힘들었던 섬유가공 효과를 간단하게 할 수 있는 기술이다. 현재 각국의 기능성 나노 가공제를 섬유에 응용하는 나노 테크놀로지는 현재 공업 생산되고 있는 면, 모, 견 등의 천연섬유 및 polyester, Nylon 등의 합성섬유의 원단에 적용하는 데서 출발하고 있다. 이러한 나노기술은 기존의 설비와 물을 사용하는 것이 큰 특징이고, 특별한 기계장치가 필요하지 않으며, 소규모의 실험장비만 있어도 현장투입이 가능한 나노입자의 제조가 가능하기 때문에 대량생산이 용이하고 설비투자는 원칙적으로 필요하지 않는다. 또한, 나노입자의 분산을 제대로 시키면 그 사이즈가 빛의 가시광선 영역의 파장(400~800nm)에 비해 절반 수준이하 크기의 입자가 대부분을 차지하기 때문에 염색성, 태의 변화가 적어 앞으로 더욱더 나노테크놀로지에 의한 가공이 확대될 것이 예상된다. 특히 유 무기 하이브리드 재료는 용액상태에서 제조되기 때문에 용액 코팅공정의 적용이 가능하여 다양한 코팅에 적극적으로 활용되고 있다. 또한 코팅공정 온도가 상대적으로 낮아서, 유기물의 기능성 발현이 용이하며, 섬유가공에 그대로 적용이 가능하고, 섬유고분자와 내구성 있게 직접 결합이 되어 실용성이 높다 할 수 있다. 또한 나노졸의 형성 시, 혹은 나노졸에 기능성 물질을 첨가함으로서 나노졸과 기능성 물질을 복합화하여 섬유상에 부여하는 것도 가능하다. 최근에 실리카졸의 형성과 성장에 관한 연구는 졸-겔 기술의 발전과 해석 및 상용화에 집중되어 있다. 규산나트륨과 황산 또는 염산을 사용하여 실리카를 생성하는 공정은 tetraethoxysilane (($Si(OC_2H_5)_4$, (TEOS))를 이용하여 합성하는 방법과 달리 대량의 실리카를 경제적으로 생산하는데 방법으로 널리 연구되고 있지만, 많은 연구가 수행되었음에도 불구하고 실리카 졸의 특성, 성장, 제조에 대한 충분한 이해가 이루어 지지 않고 있어, 아직까지 나노크기의 입자를 제조하는 공정에 대해서는 경제성, 효율성, 품질의 균일성이 떨어지는 것이 현실이다. 따라서 본 연구에서는 앞서 연구된 졸-겔 합성기술과 저렴한 원료인 규산나트륨을 이용하여 보다 간단하고 경제적인 방법으로 고부가가치의 다양한 실리카 나노졸을 제조할 수 있는 연구를 하고자 하였다. 이를 위해 규산나트륨 수용액의 특성, 핵 생성에 필요한 규산나트륨 수용액의 산화반응 특성, 그리고 출발용액의 졸겔 반응을 기초로 하여 실리카 졸 형성에 대한 반응물질의 혼합방법, 반응온도, 반응물의 농도, pH등이 최종 실리카 나노졸 제품의 입자 크기와 모양 등에 미치는 영향을 조사하려고 하며 이를 토대로 다양한 크기와 특성을 가진 실리카 나노졸을 제조하였다.

• Journal of the Korean Ceramic Society
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• v.33 no.8
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• pp.915-920
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• 1996

Fine mullite precursor was prepared by colloidal sol-gel processes. Aluminum isopropoxide $[Al(i-OC_3H_7)_3]$ as a starting material of $Al_2O_3$ and silicic acid extracted by THF from sodium silicate as a starting material of $SiO_2$ were used. Sodium silicate was first acidified by dilute sulfuric acid to form silicic acid. ; followed by extraction using THF, Mullite precursor was synthesized by sol-gel processes from aluminum isopropoxide and sillicic acid considering the degree of extraction of Si and the removal efficiency of Na. The impurity content of silicic acid extracted by THF was below 0.04% Synthetic mullite precursor consisted of $3Al_2O_3{\cdot}2SiO_2$ and showd spherical particles of $0.05{\mu}m$ diameter and below 0.462% of impurites. The mullite precursor was characterized by EDS, XRD, TG/DSC SEM, FT-IR spectroscopy ICP and TEM.

• Journal of the Korean GEO-environmental Society
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• v.13 no.8
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• pp.5-13
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• 2012

This research have investigated the application and the injection effect of the alkaline silicasol grouting materia (which is) recently developed. To compare the engineering characteristics of the alkaline silicasol which is formed with 3D-gel and the sodium silicate, it have studied the strength and environmental effects through the laboratory test, and field application was investigated with a review of the injection effect and waterproof through the field test. As a result of the laboratory test, unconfined compression strength of alkaline silicasol was 5 times more than sodium silicate. As a result of the leaching test, a total amount of the eluviated elements was very small, it considered the environment-friendly material. As a result of the field test, considerable reduction of the coefficient of permeability at the hydraulic layer was confirmed, and it could secure that the coefficient of permeability showed a lower than standard value of $10^{-5}cm/sec$.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2C
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• pp.99-108
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• 2006

In this study a series of bench scale test are conducted to increase the undrained shear strength of clayey soils using by Electro-kinetic injection stabilization method. The sodium silicate was injected in anode reservoir and its concentration was changed with 500, 1000, 1500, 2000, 2500mM for configuration of applicability of Electro-kinetic injection stabilization method. Also, the treatment time and electric gradient was changed to acquire the optical influence factors. For increasing the shear strength to maximum values, the calcium chloride and aluminium hydroxide, which concentration was changed with 50, 250, 500, 750, 1000mM, were added at anode reservoir for 5 days after the treatment of sodium silicate in 5 days as the 2nd additives. The test of results in determination of sodium silicate concentration show that the undrained shear strength at each point had a tendency to converge into a constant value when the concentration of sodium silicate came to 1000mM and above. The maximum shear strength increasement was 800% compared with initial value. After a series of test, the electric gradient and treatment time for application of electric fielld were 1V/cm and 6 days. In case of 2nd additives test, the concentration for maximum shear strength is 250mM in all additives and the effects of shear strength improvement was developed approximately 20~30% in comparison to addition of single injection material.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.163-172
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• 2003

The engineering properties of composite silicate grout materials that were developed recently were analyzed. In this laboratory tests, OPC (Ordinary Portland Cement) was mainly used as grout materials. Moreover, the properties of composite silica, silica sol and sodium silicate (No.3) acting as coagulating agent were analyzed and compared with each other. For the purpose of finding the engineering properties of composite silicate grout materials, various physical and chemical tests were performed : naked eye measurement, photographing by using SEM, uniaxial compression test and in-situ application test. A series of test results showed that the strength of composite silicate grout materials was about 3～6 times that of ordinary sodium silicate grout materials in 6～24hr. Especially, based on the evaluation of the application of JS-CGM grout to the construction fields, composite silicate grout would be very effective in reducing the coefficient of permeability.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.49-50
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• 2011

This study tried to utilize basic data for developing the cement substitute material through ternary system inorganic composite properties of flowing and strength. W/B and addition ratio of Na2SiO3 have been changed in ternary system inorganic composite combined blast furnace slag, red mud and fly ash. As to the experimental result inorganic composite, the flowing and intensity improvement effect was showed to be bigger than W/B according to the addition ratio change of the Na2SiO3. When particularly the Na2SiO3 addition ratio was 6%, the rapid flowing and strength improvement effect was confirmed.

• Journal of the Korean GEO-environmental Society
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• v.11 no.9
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• pp.47-53
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• 2010

This study was made on the fact that the compressive strength characteristic of the recently developed alkali silica-sol chemical grout material was examined, whose grout material used for this study was designed to understand its strength property through the uniaxial compressive strength test(homo-gel, sand-gel), permeability test, deflection strength test, etc. In order to compare with the engineering characteristics regarding alkali silica-sol grout material and sodium silicate grout material. The uniaxial compressive strength of silica-sol grout material was identified to be increased more than 3~5 times than sodium silicate grout material at the early stage(within 72 hours). When comparing with the uniaxial compressive strengths of Sand-gel and Homo-gel at the material age of 28 days in case of silica-sol grouting material the strength of Sand-gel was measured to be about 1.3 times higher than Homo-gel. In case of silica-sol, it is assumed to have the property to exert high strength when it is actually grouted into the ground. As a result of permeability test it is judged that it is possible to apply the silica-sol to the site in the place requiring the water cut-off as the silica-sol. As a result of testing the strength at the material age of 28 days of grouting-use silica-sol showed more than 3 times' difference than the sodium silicate grouting material.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.5
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• pp.12-20
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• 2017

This report presents the results of an investigation on the fundamental properties of mortars high fluidity high volume slag cement(HVSC) activated with sodium silicate($Na_2SiO_3$). The ordinary Portland cement(OPC) was replaced by ground granulated blast furnace slag(GGBFS) from 40% to 80% and calcium sulfoaluminate(CSA) was 2.5% or 5.0% mass. The $Na_2SiO_3$ was added at 2% and 4% by total binder(OPC+GGBFS+CSA) weight. A constant water-to-binder ratio(w/b)=0.35 was used for all mixtures. The research carried out the mini slump, V-funnel, setting time, compressive strength and drying shrinkage. The experimental results showed that the contents of superplasticizer, V-funnel, setting time and drying shrinkage increased as the contents of CSA and $Na_2SiO_3$ increase. The compressive strength increases with and an increase in CSA and $Na_2SiO_3$. One of the major reason for these results is the accelerated reactivity of GGBFS with CSA and $Na_2SiO_3$. The maximum performance was CSA 5.0% + $Na_2SiO_3$ 4% specimens.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.29-36
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• 2017

The purpose of this study is to investigate experimentally the effect of types of alkali-activators and curing conditions on the compressive and tensile behavior of fiber-reinforced cementless composites. Two types of alkali-activators and two curing conditions were determined and density test, compressive strength test, and uniaxial tension test were performed. Test results showed that the cementless composite with sodium silicate showed higher performance in terms of strength, tensile strain capacity, and toughness than that with calcium hydroxide and sodium carbonate. The effect of curing conditions depends on the types of alkali-activators.

• Journal of the Korean GEO-environmental Society
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• v.11 no.12
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• pp.13-18
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• 2010

This study was made on the fact that the environmental impact and durability of the recently developed alkali silicasol chemical grout material. The grout material used for this study was designed to understand its environmental impact and durability through the SEM, chemical resistance test, leaching test, permeability test. In order to compare with the engineering characteristics regarding alkali silicasol grout material and sodium silicate grout material. As a result of SEM, the surface and internal tissues of alkali silicasol grout material could be identified to be denser than those of sodium silicate. As a result of leaching test the adaptability was identified as grout material as it had proved to be an ecological material owing to the total amount of the element to be leached being extremely little. As a result of permeability test it is judged that it is possible to apply the silicasol to the site in the place requiring the water cut-off as the silicasol.