• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.3
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• pp.198-202
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• 2002

Ethanolamine (ETA), instead of ammonia, increases pH in the secondary system water and inhibits the corrosion of iron, which improves the integrity of the steam generator tubes. The different physicochemical properties of ETA from ammonia provide the different effect on the dissolution and adsorption of corrosion products entering the steam generator and thus on the hideout returns of ionic impurities in the steam generator sludge pile. The objective of this study was to investigate those properties with increasing temperature. ETA is more adsorbed onto the iron oxides, which increases the solubility of them and also lowers the hideout returns due to the reduced impurities adsorbed.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.4
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• pp.409-415
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• 2016

Magnetite particles were synthesized by co-precipitation of water-soluble 밀 스케일-derived precursor by various concentrations of (0.5, 0.67, 1, 2 N) NaOH and (0.6, 0.8, 1.2, 2.4 N) $NH_4OH$. It is theoretically known that as the concentration of the alkaline additive used in iron oxide synthesis increases, the particle size distribution of that iron oxide decreases. This trend was observed in both kind of alkaline additive used, NaOH and $NH_4OH$. In addition, the magnetite synthesized in NaOH showed a relatively smaller particle size distribution than magnetite synthesized in $NH_4OH$. Crystalline phase of the synthesized magnetite were determined by X-ray diffraction spectroscopy(XRD). The particles were then used as an adsorbent for phosphate(P) removal. Phosphorus adsorption was found to be more efficient in NaOH-based synthesized magnetite than the $NH_4OH$-based magnetite.

• Particle and aerosol research
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• v.9 no.4
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• pp.209-219
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• 2013

We have used the modified diffusion flame burner to synthesize silica coated iron oxide nanoparticles having enhanced superparamagnetic property. Silica-encapsulated iron oxide particles were directly observed using a high resolution transmission electron microscope. From the energy dispersive X-ray spectroscopy (EDS) and zeta potential measurements, the iron oxide particles were found to be completely covered by a silica coating layer. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) measurements revealed that the iron oxide core consists of ${\gamma}-Fe_2O_3$ rather than ${\alpha}-Fe_2O_3$. Our magnetization measurements support this conclusion. Biocompatibility test of the silica-coated iron oxide nanoparticles is also conducted using the protein adsorption onto the coated particle.

• Carbon letters
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• v.14 no.4
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• pp.206-209
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• 2013

Nanocomposites comprised of graphene oxide (GO) nanosheets and magnesium oxide (MgO) nanoparticles were synthesized by a sol-gel process. The synthesized samples were studied by X-ray powder diffraction, atomic force microscopy, transmission electron microscopy, and energy-dispersive X-ray analysis. The results show that the MgO nanoparticles, with an average diameter of 70 nm, are decorated uniformly on the surface of the GOs. By controlling the concentration of the MgO precursors and reaction cycles, it was possible to control the loading density and the size of the resulting MgO particles. Because the MgO particles are robustly anchored on the GO structure, the MgO/GOs nanocomposites will have future applications in the fields of adsorption and chemical sensing.

• Applied Chemistry for Engineering
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• v.30 no.4
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• pp.460-465
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• 2019

In this study, the optimization of active materials and the preparation of particulate adsorbents for the application of metal oxide-based adsorbents for the treatment of $H_2S$, an air pollutant and odorant, occurred in various industrial facilities were investigated. The adsorbents were prepared by using $TiO_2$, which has a high physicochemical stability and relatively high specific surface area among metal oxides and also by different kinds and contents of active materials. The correlation between the physicochemical property and adsorption performance of the adsorbents confirmed that the adsorbent containing KI, which is a typical alkali metal among the active metals, showed the highest adsorption performance. The relationship between the contents and the adsorption performance was non-proportional, but a volcano plot. From XRD, SEM and BET analyses, it was confirmed that the active material was exposed to the surface above a certain amount and also the adsorption performance was the best when the specific surface area and pore volume were $40{\sim}100m^2/g$ and $0.1{\sim}0.3cm^3/g$, respectively. For practical application, the adsorbent was granulated or coated on a ceramic support. It was also confirmed that the adsorbent showed high adsorption performance when the adsorbent was coated on the ceramic rather than that of the granulated support.

• Journal of Environmental Science International
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• v.24 no.5
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• pp.641-646
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• 2015

In order to recover lithium ions from aqueous solution, a novel SAN-LMO beads were prepared by immobilizing lithium manganese oxide (LMO) with styrene acrylonitrile copolymers (SAN). The optimum condition for synthesis of SAN-LMO beads was 5 g of LMO and 3 g of SAN content. The characterization of the prepared SAN-LMO beads by SEM and XRD were confirmed that LMO was immobilized in SAN-LMO beads. The removal and the distribution coefficient of lithium ions decreased with increasing lithium ion concentration and solution pH. Even when the prepared SAN-LMO beads were reused 5 times, the leakage of LMO and the damage of SAN-LMO beads was not observed.

• Journal of the Korean Chemical Society
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• v.58 no.2
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• pp.205-209
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• 2014

Hematite iron oxide (${\alpha}$-$Fe_2O_3$) nanowalls were fabricated on aluminum substrate by a facile solvent-assisted hydrothermal oxidation process. The XRD and EDS patterns indicate that the sample has a rhombohedral phase of hematite $Fe_2O_3$. FE-SEM, TEM, HR-TEM, SA-ED were employed to characterize the resulting materials. $N_2$ adsorption-desorption isotherms was used to study a BET surface area. Their capability of catalytic degradation of titan yellow GR azo dye with air oxygen in aqueous solution over $Fe_2O_3$ catalysts was studied. The result indicates that the as-prepared product has a high catalytic activity, because it has a larger surface area. Langmuir and Freundlich isotherms of adsorption dye on the catalysts surface were investigated and the decomposition of titan yellow GR follows pseudo-first order kinetic.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.64-65
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• 2016

This study that prevent cancer using absorbent to inflow Radon gas in the room existing soil and rock is making board to absorb the Radon gas as a fundamental study. So, we use bentonite as a absorbent. So, we use bentonite as a absorbent. Bentonite is a 'clay mineral' composed to montmorillonite of main component that volcanic ash denatured to a clay mineral. Bentonite has fine microparticle of nano level, abundant mineral 66 of kinds, adsorbability, swelling, a positive ion(heavy metal adsorption reaction) as a bentonite's property. Using magnesia cement for oxide of magnesiuma and magnesium chloride as a main binder, we measure Radon gas absorbent efficiency and thermal conductivity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.272-275
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• 2002

An ozone condensation system is evaluated in the viewpoint of an ozone supplier for oxide thin film growth. Ozone is condensed by the adsorption and distillation method. Then their concentrations are analyzed by three methods; ultraviolet absorption, thermal decomposition and Q-mass analyzing methods. Thermal decomposition method is found to be available to the concentration evaluation from dilution to highly condensed ozone. The highest ozone concentration condensed by the adsorption method is evaluated to be 96 mol%. The ozone is supplied for a sufficiently long time to grow oxide thin films.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.110-116
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• 2003

We have developed a high performance powder, which has a quenching efficacy not only for short-chain fatty acids and amines, but also for vinyl ketones (l-octen-3-one, cis-l,5-octadien-3-one), newly found as other key compounds in axillary malodor. By investigating various powders known to have a quenching efficacy, we finally developed a highly porous silica bead containing magnesium oxide. We found that the superior deodorant effect performed by this powder was the result of multiple effects due to both an excellent physical adsorption capability from its high porosity and a specific adsorption of vinyl ketones by magnesium in the powder. An antiperspirant formulation containing both this powder and a Morus alba extract showed good efficacy as a deodorant.