• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.74-74
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• 2002

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.96-96
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• 2002

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.158-166
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• 2017

The object of this study was to improve tomato seedling quality in low temperature(below 7, $10^{\circ}C$ during night time or daily mean air temperature was $18^{\circ}C$) by application of silicate fertilizer. Six different silicate fertilizer concentrations (8, 16, 32, 64, 128, and 256mM) or water as the control were applied to tomato seedlings twice a week for 20 days. Positive effects were observed in the growth parameters of the seedlings treated with 16 and 32mM silicate fertilizer; the most effective concentration of silicate at which seedlings showed the best performance was 16mM. However, a high concentration of silicate (256mM) caused negative effects on the growth. The transpiration rate decreased alongside with the increase of silicate concentration up to 32mM, possibly due to the increased stomatal diffusive resistance. Silicate stimulated the growth and development of tomato seedlings, resulting in increased growth parameters and root morphology. However, no significant differences were observed among treatment numbers of soil-drenching wuth the silicate (6, 10, or 20 times with 16mM) for 20 days, suggesting that silicate treatment with 6 times may be sufficient to induce the silicate effects. The application of 16mM of silicate fertilizer reduced relative ion leakage and chilling injury during low temperature storage. In addition, the seedlings treated with silicate fertilizer recovered faster than those without silicate treatment after low temperature storage.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.84-91
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• 2020

The efficiency of the synthetic magnesium silicate used in basic polyols and edible oil purification is evaluated by its purification ability and filtration rate and is affected by the particle size and surface area of magnesium silicate. In this study, it was investigated the change on the particle size of magnesium silicate was influenced by the reaction temperature, injection rate, injection order (Si, Mg) and Mg/Si reaction mole ratio. The synthesized magnesium silicate was compared and analyzed for the synthesis, grinding, and refining processes. In the synthesis process, the reaction temperature and feed rate did not affect the average particle size change of magnesium silicate, while the reaction molar ratio of Mg / Si and the order of injection acted as main factors for the change of average particle size. The average particle size of magnesium silicate increased by 8.7 ㎛ from 54.4 ㎛ to 63.1 ㎛ at Mg injection when Mg molar ratio increased from 0.125 to 0.500, and increased by about 4.8 ㎛ from 47.3 ㎛ to 52.1 ㎛ at Si injection. The average particle size according to the order of injection was 59.1 ㎛ for Mg injection and 48.4 ㎛ for Si injection and the difference was shown 10.7 ㎛, therefore the filtration rate was about 2 times faster under the condition of Mg injection. That is, as the particle size increases, the filtration time is shortened and washing filtration rate can be increased to improve the productivity of magnesium silicate. The cake form of separated magnesium silicate after filtration becomes a solid through drying process and is used as powdery adsorbent through the grinding process. As the physical strength of the dried magnesium silicate increased, the average particle size of the powder increased and it was confirmed that this strength was affected by the reaction molar ratio. As the reaction molar ratio of Mg / Si increased, the physical strength of magnesium silicate decreased and the average particle size after grinding decreased by about 40% compared to the average particle size after synthesis. This reduction of strength resulted in an improvement of the refining ability due to the decrease of the average particle size and the increase of the amount of fine particle after the pulverization, but it resulted in the decrease of the purification filtration rate. While the molar ratio of Mg/Si was increased from 0.125 to 0.5 at Mg injection, the refining ability increased about 1.3 times, but the purification filtration rate decreased about 1.5 times. Therefore, in order to improve the productivity of magnesium silicate, the reaction molar ratio of Mg / Si should be increased, but in order to increase the purification filtration rate of the polyol, the reaction molar ratio should be decreased. In the synthesis parameters of magnesium silicate, the order of injection and the reaction molar ratio of Mg / Si are important factors affecting the changes in average particle size after synthesis and the changes of particle size after grinding due to the changes of compressive strength, therefore the synthetic parameter is an important thing that determines productivity and refining capacity.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.354-363
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• 2007

In order to investigate the optimum rate and interval of silicate fertilizer application for rice cultivation, Chucheong byeo variety, one of commonly cultivated rice cultivar in Korea was planted on two different wetland rice soils located on Hwaseong-si from 2002 to 2005; Jisan series(a member of the fine loamy, mixed, mesic family of Fluvaquentic Endoaquepts), known as "Productive Paddy Soil", without any conspicuous limiting factor, and Seokcheon series (a member of the coarse loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquetps), known as "Sandy Paddy Soil", sandiness being major limiting factor. There were three rate treatments of silicate fertilizer application; the amount of silicate fertilizers needed to adjust the available soil silicate contents to 130, 200, and $270mg\;kg^{-1}$ was applied, in the first year only. There was an additional plot; applying the amount of silicate fertilizer needed to adjust soil available silicate to 130 ppm every year, which would serve as the base for the evaluation of residual effects of silicate fertilizers in the plots where different rates of silicate fertilizer were applied. From the yield data in first year, it was found that optimum available silica in the soil are $154mg\;kg^{-1$ and $160mg\;kg^{-1}$, in Jisan and Seogcheon soils, respectably. The duration of residual effects of silicate fertilizer was different depending upon the amount of applied silicate fertilizers and the soils. The higher the application rate, the residual effect lasted longer, and the residual effect was lasted longer in Jisan(clay loam) soil than in Seogcheon(sandy loam) soil. During four years, sum of the rate of contribution to increase available soil silica of applied silicate fertilizer in different soils ranged 18.6% and 24.1% in Jisan soil and Seogcheon soil, respectively. This may suggest that much portion of applied silicate would be either lost from the soil or remain in the soil as insoluble form. This deserves further study.

• Journal of the Korean GEO-environmental Society
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• v.7 no.4
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• pp.25-34
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• 2006

Portland cement and sodium silicate are widely used as the main components of the injection, which are used to prevent flow and improve ground condition. The main problem of the injection material is the leaching of the sodium hydroxite and silicate due to the limited reaction with the cement. This paper studies the effect of cement hydration retarder on the compressive strength of the sodium silicate - cement gel. A series of tests, including digital-type testing machine, X-ray diffraction and scanning electron microscope are performed. Results clearly demonstrate that the sodium tripolyphosphate, which is the cement hydration retarder in the test, significantly improves the initial strength of the homogel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.955-960
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• 2012

In this study, pure Polyurethane and commonly used flame retardants $Al(OH)_3$ and $Mg(OH)_2$, the add-in sample and Cloisite Na+, Cloisite 15A added sample of flammability and mechanical properties are compared. Sodium silicate and a mixture of polyurethane that the lightweight filler Vermiculite, Perlite addition of flame retardant and mechanical properties of the sample was confirmed. As a result, the flame retardant additive in the Vermiculite and Perlite in a flame-retardant grade sample except sample were identified. Tensile strength is degrade accord to the filler amount. But, Sodium silicate in the case of the sample add-in, other than confirmed that the sample strength increases.

• Macromolecular Research
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• v.13 no.2
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• pp.156-161
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• 2005

The thermal transitions of a nylon 6/layered silicate nanocomposite were studied by differential scanning calorimetry and in-situ synchrotron X-ray diffraction. The drawn film of the nylon 6/layered silicate nanocomposite typically showed three endotherms in the DSC thermogram; a very broad endotherm at $\sim120^{\circ}C(T_{1})$, a double-melting endotherm at $\sim215^{\circ}C(T_{2})$, and a high temperature endotherm at $\sim240^{\circ}C(T_{3})$. The drawn film of the nylon 6/ layered silicate nanocomposite was comprised of a mixture of the $\alpha and \gamma$ forms, with $the \alpha form$ being generated by drawing the pressed film having $the \gamma form$. The melting and crystallization of the crystals were observed at the above thermal transitions during the heating experiment performed at the Pohang X-ray synchrotron radiation source (4C2). The newly generated form was meta-stable and melted $at {\sim}T_{1}$. The double-melting $at {\sim}T_{2}$ was due to the exothermic crystallization of $the \alpha form$ during the main endothermic melting of $the \gamma form$. $The \alpha form$ crystallized $at {\sim}T_{2}$ and melted $at {\sim}T_{3}$.

• Journal of the Korean Ceramic Society
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• v.51 no.1
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• pp.7-10
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• 2014

Abalone shell is composed of 95 wt% $CaCO_3$ platelets and 5 wt% of a protein-rich organic matrix which acts as an adhesive layer, connecting aragonite tablets, thus maintaining the structural integrity of the composite. By mimicking abalone shell, we prepared a silicate plate/polymer nanocomposite by infiltrating PMMA between silicate layers and warm-pressing them at $200^{\circ}C$ for 1 h under 15 tons to make organic-inorganic composite materials. To examine the organic-inorganic composite materials after the warm-pressing procedure, the composite sample was analyzed with FE-SEM and TG. The bending strengths and densities of the composites prepared by a silicate plate and PMMA after the warm-pressing process were ~140 MPa and 1.5, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.171-174
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• 2000

We have investigated the CMP slurry properties of silicate oxide thin films surface on CMP cleaning process. The metallic contaminations by CMP slurry were evaluated in four different oxide films, such as plasma enhanced tetra-ethyl-ortho-silicate glass(PE-TEOS), $O_3$ boro-phospho silicate giass( $O_3$-BPSG), PE-BPSG, and phospho-silicate glass(PSG). All films were polished with KOH-based slurry prior to entering the post-CMP cleaner. The Total X-Ray Fluorescence(TXRF) measurements showed that all oxide surfaces are heavily contaminated by potassium and calcium during polishing, which is due to a CMP slurry. The polished $O_3$-BPSG films presented higher potassium and calcium contaminations compared to PE-TEOS because of a mobile ions gettering ability of phosphorus. For PSG oxides, the slurry induced mobile ion contamination increased with an increase of phosphorus contents.