• Journal of Environmental Science International
• /
• v.27 no.7
• /
• pp.611-620
• /
• 2018

In this study, a metal-organic framework (MOF) material $NH_2$-MIL-101(Fe) was synthesized using the solvothermal method, and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-visible spectrophotometry, field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and surface area measurements. The XRD pattern of the synthesized $NH_2$-MIL-101(Fe) was similar to the previously reported patterns of MIL-101 type materials, which indicated the successful synthesis of $NH_2$-MIL-101(Fe). The FT-IR spectrum showed the molecular structure and functional groups of the synthesized $NH_2$-MIL-101(Fe). The UV-visible absorbance spectrum indicated that the synthesized material could be activated as a photocatalyst under visible light irradiation. FE-SEM and TEM images showed the formation of hexagonal microspindle structures in the synthesized $NH_2$-MIL-101(Fe). Furthermore, the EDS spectrum indicated that the synthesized material consisted of Fe, N, O, and C elements. The synthesized $NH_2$-MIL-101(Fe) was then employed as an adsorbent and photocatalyst for the removal of Indigo carmine and Rhodamine B from aqueous solutions. The initial 30 min of adsorption for Indigo carmine and Rhodamine B without light irradiation achieved removal efficiencies of 83.6% and 70.7%, respectively. The removal efficiencies thereafter gradually increased with visible light irradiation for 180 min, and the overall removal efficiencies for Indigo carmine and Rhodamine B were 94.2% and 83.5%, respectively. These results indicate that the synthesized MOF material can be effectively applied as an adsorbent and photocatalyst for the removal of dyes.

• Journal of the Korean Society of Costume
• /
• v.57 no.1 s.110
• /
• pp.93-104
• /
• 2007

This study is considered about the fabrics culture of Baekje Period by analyzing the fabrics pieces at a inner part of the It-bronze shoes found at the tomb of King Mu-ryeong in 1971 AD. The analysis methods of the fabrics pieces are a photographing of fabrics pieces surface by VMS, Digital camera(Nikon Coolpix 995) and the analysis of samples by SEM, XRD and FT-IR. It is assumed this fabrics pieces are the inner shoes, which consisted of compound woven silk at outward, some of tabby and a hemp at inward and the braids for decoration, of the gilt-bronze shoes. The features are as follows. 1. All of compound woven silk are the warp-faced compound tabby of plain fabrics and the density is various from high to low one. Compound woven silk which is attached the gilt-bronze shoes of the tomb of King Mu-ryeong weaves in high density by a thick thread. The fibers material of compound woven silk prove to be a silk by the analysis of wrap samples by SEM, XRD and FT-IR. 2. Tabby are excavated under the condition which attached on reverse side of compound woven silk. Those ran classify two types. First, the fine weaving by high density of wrap and weft. Second, the loose warp weaving with one warp and some of weft. 3. Hemp is almost ramie by SEM analysis and the density is different. Ramie which supposed to be attached Guem has the very low density. In addition to, Ramie pieces, excavated in condition and weaved finely, proved the conspicuous weaving skill in Baekje period. 4. Various kinds of braid are found and these ones classifies by fiber material and entwining way. Two types out of these are the one of silk thread, decorates the upper, middle parts of compound woven silk shoes and the other of hemp thread, decorates the lower parts.

• Applied Chemistry for Engineering
• /
• v.27 no.3
• /
• pp.265-269
• /
• 2016

Ammonia gas as a hydrogen source has received great attention since the importance of hydrogen gas as a clean energy source increased. However, ammonia is toxic and corrosive to metal such that the absorbent that can store and transport ammonia became an important issue. As an effort to solve this, a large pored covalent organic framework, COF-10 was proposed as an adsorbent for storage and safe transportation of ammonia. During the ammonia adsorption process, boron in COF-10 structure can act as a Lewis acid site and bind with ammonia. In this study, COF was synthesized and its structure was identified by BET, XRD and FT-IR. The adsorption characteristics of COF were investigated by TPD and adsorption isotherm. The COF-10 showed an excellent adsorption capacity for ammonia (9.79 mmol/g) which could be utilized as an ammonia adsorbent.

• Journal of Environmental Science International
• /
• v.30 no.1
• /
• pp.97-108
• /
• 2021

In the current study, MIL-101(Cr)-SO3H[HCl] as metal-organic frameworks (MOFs) was fabricated via a hydrothermal method. The physicochemical properties of the synthesized material were characterized using XRD, FT-IR, FE-SEM, TEM, and BET surface area analysis. The XRD diffraction pattern of the prepared MIL-101(Cr)-SO3H[HCl] was similar to previously reported patterns of MIL-101(Cr) type materials, indicating successful synthesis of MIL-101(Cr)-SO3H[HCl]. The FT-IR spectrum revealed the molecular structure and functional groups of the synthesized MIL-101(Cr)-SO3H[HCl]. FE-SEM and TEM images indicated the formation of rectangular parallelopiped structures in the prepared MIL-101(Cr)-SO3H[HCl]. Furthermore, the EDS spectrum showed that the synthesized material consisted of the elements of Cr, O, S, and C. The fabricated MIL-101(Cr)-SO3H[HCl] was then employed as an adsorbent for the removal of Sr2+ and Cs+ from aqueous solutions. The adsorption kinetics and adsorption isotherm models were studied in detail. The maximum adsorption capacities of MIL-101(Cr)-SO3H[HCl] for Sr2+ and Cs+ according to pH (3, 5.3~5.8, 10) were 35.05, 43.35, and 79.72 mg/g and 78.58, 74.58, and 169.74 mg/g, respectively. These results demonstrate the potential of the synthesized MOFs, which can be effectively applied as an adsorbent for the removal of Sr2+ and Cs+ ions from aqueous solutions and other diverse applications.

• Korean Chemical Engineering Research
• /
• v.46 no.3
• /
• pp.529-534
• /
• 2008

The normal shell and the regenerated oyster shell, Crassostrea gigas, are separated according to the characteristics of inner shell morphology. To study characteristics of chitin obtained from the regenerated shell, chitin prepared by acid and alkali process is analyzed by FT-IR (Fourier transform infrared spectrometer) and XRD (X-ray Diffractometer). The content of insoluble protein in the normal shell was more than doubled as compared with that in the regenerated shell. A comparison of secondary structure of the normal shell and the regenerated shell revealed that the content of random of the regenerated shell was above 47%, indicating an amount in the structural unordered state. Through amino acid composition analysis and secondary protein structure of soluble protein isolated from the normal shell and the regenerated shell, it was found that there are differences in biomineralization strategy of the regenerated shell as compared to the normal shell. The relatively low hardness of the regenerated shell is caused by the change of amino acid composition and ordered secondary protein structure as compared to hardness of the normal shell.

• Applied Chemistry for Engineering
• /
• v.29 no.1
• /
• pp.67-76
• /
• 2018

In this study, PDMS-HNT and PDMS-mHNT composite membranes were prepared by the addition of halloysite nanotube (HNT) and modified HNT (mHNT) to PDMS. To investigate the physico-chemical characteristics of composite membranes, analytical methods such as FT-IR, XRD, TGA, and SEM were utilized. The gas permeability and selectivity properties of $N_2$ and $CO_2$ were evaluated. In particular, the PDMS-HNT with 10 wt% HNT and PDMS-mHNT with 5 wt% mHNT showed the highest $CO_2/N_2$ selectivity and $CO_2$ permeability at $35^{\circ}C$, respectively. Overall, PDMS-HNT and PDMS-mHNT composite membranes improved the $CO_2/N_2$ selectivity compared to that of using PDMS membrane.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.23 no.2
• /
• pp.199-207
• /
• 2015

Solid materials of ammonia sources with SCR have been considered for the application of lean NOx reduction in automobile industry, to overcome complex problems of liquid urea based SCR. These solid materials produce ammonia gas directly with proper heating and can be packaged by compact size, because of high volumetric ammonia density. Among ammonium salts and metal ammine chlorides, calcium ammine chloride was focused on this paper due to low decomposition temperature. In order to make calcium ammine chloride in lab-scale, simple reactor and glove box was designed and built with ammonium gas tank, regulator, and sensors. Basic test conditions of charging ammonia gas to anhydrous calcium chloride are chosen from equilibrium vapor pressure by Van't Hoff plot based on thermodynamic properties of materials. Synthetic method of calcium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%) from simple weight calculations which were confirmed by IC. Also, lab-made calcium ammine chloride were analyzed by TGA and DSC to clarify decomposition step in the equations of chemical reaction. To understand material characteristics for lab-made calcium ammine chloride, DA, XRD and FT-IR analysis were performed with published data of literature. From analytical results, water content in lab-made calcium ammine chloride can be discovered and new test procedures of water removal were proposed.

• Journal of the Korean Applied Science and Technology
• /
• v.33 no.1
• /
• pp.23-29
• /
• 2016

Zinc oxide of hexagonal wurzite, is known as n-type semiconductor. It has a wide band gap energy of 3.37 eV and large exciton binding energy of 60 meV. It can be widely applied to gas sensors, laser diodes, dye-sensitized solar cells and degradation of dye waste. The use of microwave hydrothermal synthesis brings a rapid reaction rate, high yield, and energy saving. Amine additives control the different particle shapes because of the chelate effect and formation of hydroxide ion. In this study, zinc nitrate hexahydrate was used as zinc precursor. In addition, ethanolamine, ethylenediamine, diethylenetriamine, and hexamethylenetetramine are used as shape control agent. The pH value was controlled as 11 by NaOH. The shapes of zinc oxide are star-like, rod, flower-like, and circular cone. In order to analyze physical, chemical, and optical properties of ZnO with diverse amine additives, we used XRD, SEM, EDS, FT-IR, UV-Vis spectroscopy, and PL spectroscopy.

• Journal of Adhesion and Interface
• /
• v.12 no.4
• /
• pp.133-137
• /
• 2011

Exfoliated graphite oxide (EGO) was prepared by graphite oxide in an aqueous solution of TMAOH. The hybrid graphene/Zn-Al LDH material was fabricated by the hydrothermal reduction of the solution of EGO, $Zn(NO_3)_2{\cdot}6H_2O$, $Al(NO_3)_3{\cdot}9H_2O$, urea, and trisodium citrate. That is, metal ions were absorbed on the surface of EGO, and Zn-Al LDH material was randomly dispersed on the surface of graphene along with a reduction process of EGO to graphene by hydrothermal treatment. The composition, morphology, and thermal property of the obtained graphene-based hybrid material were studied by FE-SEM, EDX, TEM, FT-IR, XRD, TGA, and DSC.

• Applied Chemistry for Engineering
• /
• v.31 no.1
• /
• pp.49-56
• /
• 2020

In this study, surface modification of CaCO₃ nanoparticles by a silane coupling agent propyltrimethoxysilane (PTMS) was conducted and the effect of surface hydrophobicity on the stability of foam and emulsion was studied in order to test the potential applicability as a foam stabilizer or an emulsifier. The surface modification of CaCO₃ nanoparticles by PTMS was confirmed by FT-IR, DSC and TGA analysis. The atomic concentration of CaCO₃ particle surface treated by PTMS has been also identified by using XRD and XPS analyses. Both floating tests and contact angle measurements were also performed to examine the effect of PTMS concentration on the surface modification of CaCO₃ nanoparticles.