본 연구에서는 현탁중합을 통해 이온교환입자를 합성하였다. 또한 음이온 교환막을 제조하기 위해 brominated poly(phenylene oxide) (Br-PPO)로 교환막 합성을 진행하였으며, 합성한 이온교환입자를 Br-PPO에 첨가하여 음이온 교환막 에 성능을 향상시키고자 하였고, 이를 적용하여 음이온 교환막 연료전지 시스템의 성능 평가를 진행했다. 이온교환입자는 FT-IR, TGA 및 UTM을 통해 구조 분석, 열적 기계적 특성을 평가하였다. Br-PPO는 NMR을 통해 화학적 구조 분석 및 합성 여부를 확인하였고, 음이온 교환막 연료 전지 셀 테스트를 진행하기 전 이온전도도와 이온교환용량, 팽윤도 및 수분함수율을 측정해 연구되고 있는 다른 음이온 교환막들과 비교를 통해 성능을 평가했다. 최종적으로 가장 성능이 우수했던 이온교환입 자를 0.7 wt%를 첨가한 Br-PPO-TMA- SDV 음이온 교환막을 연료전지 시스템에 도입하여 상용 막인 FAA-3-50과 성능을 비 교했다.

Cutting reactor pressure vessels (RPV) into acceptable sizes for waste disposal is a key process in dismantling nuclear power plants. In the case of Kori-1, a remote oxyfuel cutting method has been developed by Doosan Heavy Industry & Construction to dismantle RPVs. Cutting radioactive material, such as RPV, generates a large number of fine and ultrafine particles incorporating radioactive isotopes. To minimize radiological exposure of dismantling workers and workplace surface contamination, understanding the characteristics of radioactive aerosols from the cutting process is crucial. However, there is a paucity of knowledge of the by-products of the cutting process. To overcome the limitations, a mock-up RPV cutting experiment was designed and established to investigate the characteristics of fine and ultrafine particles from the remote cutting process of the RPV at the Nuclear Decommissioning Center of Doosan Heavy Industry & Construction. The aerosol measurement system was composed of a cutting system, purification system, sampling system, and measurement device. The cutting system has a shielding tent and oxyfuel cutting torch and remote cutting robot arm. It was designed to prevent fine particle leakage. The shielding tent acts as a cutting chamber and is connected to the purification system. The purification system operates a pressure difference by generating an airflow which delivers aerosols from the cutting system to the purification system. The sampling system was installed at the center of the pipe which connects the shielding tent and purification system and was carefully designed to achieve isokinetic sampling for unbiased sampling. Sampled aerosols were delivered to the measurement device. A high-resolution electrical low-pressure impactor (HR-ELPI+, Dekati) is used to measure the size distribution of inhalable aerosols (Aerodynamic diameter: 6 nm to 10 μm) and to collect size classified aerosols. In this work, the mock-up reactor vessel was cut 3 times to measure the number distribution of fine and ultrafine particles and mass distribution of iron, chromium, nickel, and manganese. The number distribution of aerosols showed the bi-modal distribution; two peaks were positioned at 0.01−0.02 μm and 0.04–0.07 μm respectively. The mass distribution of metal elements showed bi-modal and trimodal distribution. Such results could be criteria for filter selection to be used in the filtration system for the cutting process and fundamental data for internal dose assessment for accidents. Future work includes the investigations relationships between the characteristics of the generated aerosols and physicochemical properties of metal elements.

The purpose of this study is to optimize the powder formulation and manufacturing conditions for the solidification of an extract of the herb Bangpungtongseong-san (BPTS). To develop BPTS-loaded particles for the tablet dosage form, various BPTS-loaded particles composed of BPTS, dextrin, microcrystalline cellulose (MCC), silicon dioxide, ethanol, and water are prepared using spray-drying and high shear granulation (high-speed mixing). Their physical properties are evaluated using scanning electron microscopy and measurements of the angle of repose, Hausner ratio, Carr’s index, hardness, and disintegration time. The optimal BPTS-loaded particles exhibit improved flowability and compressibility. In particular, the BPTS-loaded particles containing silicon dioxide show significantly improved flowability and compressibility (the angle of repose, Hausner ratio, and Carr’s index are 35.27 ± 0.58°, 1.18 ± 0.06, and 15.67 ± 1.68%, respectively), hardness (18.97 ± 1.00 KP), and disintegration time (17.60 ± 1.50 min) compared to those without silicon dioxide. Therefore, this study suggests that particles prepared by high-speed mixing can be used to greatly improve the flowability and compressibility of BPTS using MCC and silicon dioxide.

To develop Gastrodia elata (GE)-loaded particles for herbal extract dosage forms, various GE-loaded particles containing dextrin, isomalt, maltodextrin, and silicon dioxide as solidifying carriers in the GE water extract are prepared using the spray drying method. Their physical properties are evaluated using the repose angle, Hausner ratio, Carr's index, weight increase rate at 40oC/75% RH condition, and scanning electron microscopy (SEM). Particles made of dextrin improve the fluidity, compressibility, and water stability. In addition, 2% silicon dioxide increases the fluidity and moisture stability. The best flowability and compressibility of GE-loaded particles are observed with TP, dextrin, and silicon dioxide amounts in the ratio of 6/4/0.2 (34.29 ± 2.86°, 1.48 ± 0.03, and 38.29 ± 2.39%, repose angle, Hausner Ratio, and Carr’s index, respectively) and moisture stability with a 2% weight increase rate for 14 h at 40oC/75% RH condition. Therefore, our results suggest that the particles prepared by the spray drying method with dextrin and 2% silicon dioxide can be used as powerful particles to improve the flowability, compressibility, and moisture stability of GE.

To develop Taraxacum platycarpum extract (TP)-loaded particles for tablet dosage form, various TP-loaded particles composed of TP, dextrin, microcrystalline cellulose (MCC), silicon dioxide, ethanol, and water are prepared using a spray-drying method and fluid-bed-drying method. Their physical properties are evaluated using angle of repose, Hausner ratio, Carr’s index, hardness, disintegrant time, and scanning electron microscopy. Optimal TP-loaded particles improve flowability and compressibility. Furthermore, 2% silicon dioxide gives increased flowability and compressibility. The formula of TP-loaded fluid-bed-drying particles at a TP/MCC/silicon-dioxide amount of 5/5/0.2 improves the angle of repose, Hausner ratio, Carr’s index, hardness, and disintegrant time as compared with the TP-loaded spray-drying particles. The TP-loaded fluid-bed-drying particles considerably improve flowability and compressibility (35.10° vs. 40.3°, 0.97 vs. 1.17, and 18.97% vs. 28.97% for the angle of repose, Hausner ratio, and Carr’s index, respectively), hardness (11.34 vs. 4.7 KP), and disintegrant time (7.4 vs. 10.4 min) as compared with the TP-loaded spray-drying particles. Thus, the results suggest that these fluid-bed-drying particles with MCC and silicon dioxide can be used as powerful particles to improve the flowability and compressibility of the TP.

Hydroxy sodalite (HS) is reported as high-temperature water separating zeolite membrane because of its small β-cage structure (pore size=2.8Å). HS zeolite particles were synthesized using various experimental set-ups including water bath, oil bath, refluxing and hydrothermal method using a gel composition of 5SiO2:1Al2O3:50Na2O:1000H2O. The morphology, crystallinity and purity of HS particles by changing silica source, temperature and synthesis time were studied. The products were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM). Particle sizes were increased with increase of temperature (90 °C - 180 °C) and time (2 – 24 h). Pure HS particles were obtained by using conventional hydrothermal synthesis at 120°C for 2h.

본 연구에서는 유화중합을 이용하여 폴리스타이렌계 나노사이즈의 입자를 제조하였으며 이를 후술폰화 공정을 이용하여 술폰산기를 도입시킨 고분자 입자를 제조 하였으며, 이를 이용하여 술폰화된 PEEK내에 도입하여 복합막을 제조하였다. 도입된 입자의 경우 고분자 분리막 내에 고르게 분산이 되었으며 제조된 분리막의 경우 입자의 함량이 증가됨에 따라 향상된 이온교환 능력 및 프로톤 전도도를 나타냄으로써 연료전지용 젼해질 막으로써의 적용가능성을 확인할 수 있었다.

Ag nanoparticles are extensively studied and utilized due to their excellent catalysis, antibiosis and optical properties. They can be easily synthesized by chemical reduction methods and it is possible to prepare particles of uniform size and high purity. These methods are divided into vapor methods and liquid phase reduction methods. In the present study, Ag particles are prepared and analyzed through two chemical reduction methods using solvents containing a silver nitrate precursor. When Ag ions are reduced using a reductant in the aqueous solution, it is possible to control the Ag particle size by controlling the formic acid ratio. In addition, in the Polyol process, Ag nanoparticles prepared at various temperatures and reaction time conditions have multiple twinned and anisotropic structures, and the particle size variation can be confirmed using field emissions scanning electron microscopy and by analyzing the UV-vis spectrum.

이번 연구에서는 기존의 이온교환 수지를 대체 할 수 있는 물질에 대한 연구를 진행하였다. 이에 대한 물질로는 유화중합을 통해 Styrene monomer를 활용한 Polystyrene particle을 제조하였다. 이온기가 도입된 입자의 경우 기존의 이온교환수지보다 표면적이 훨씬 크고, 입자 크기가 작아 좁은 분포를 나타내어 더 높은 이온 교환 용량을 나타냄을 확인 하였다. 단분산된 입자에 Sulfonation 반응을 통해 -SO3 -관능기를 도입하였으며 이외에도 -COO-, -PO3 -, -C6H4O- 등의 관능기를 도입함으로써 SEBS 고분자 분리막을 음전하로 높게 하전 시킬 수 있 었다. 입자를 제조하고 이에 따른 특성평가는 SEM, FT-IR, Zeta potential, IEC value등의 전기적 특성과 TGA, DSC 등의 열적 특성을 파악하였다.

본 연구에서는 기존의 음이온 교환 수지를 대체하기 위한 물질로써 Emulsion polymerization을 통해 Polystyrene Latex입자를 제조하였다. 관능기를 도입한 입자를 활용하였을 때 기존의 이온교환 수지가 가지고 있는 특성보다 좁은 분 포도를 가지며 훨씬 높은 표면적을 나타낸다. 단분산된 나노크기의 입자에 Chloromethylation과 Amination 반응을 통해 -NH3 +, -NR3 +, -PR3 +, -SR2 + 등의 관능기를 도입함으로써 SEBS 고분자 분리막을 양전하로 높게 하전시킬 수 있다. 입자를 제조하고 SEM, FT-IR, Zeta potential, IEC value 등의 전기적 및 TGA, DSC등의 열적인 부분을 특성평가 진행하였다.

Poly-methylmetacrylate (PMMA) is mainly applied in the plastic manufacturing industry, but PMMA is weak and gradually got discolor. The strength of PMMA can be improved through organic-inorganic hybrid nano composites with inorganic nano particles such as, SiO2 or ZrO. However, inorganic nano particles are mostly agglomerated spontaneously. In this study, the zeta potential is controlled using different types of organic solvent with different concentrations, dispersibillity of SiO2 nano particles on the PMMA particle are analyzed. When 3 M acetic acid is used, absolute value of the zeta potential is higher, SiO2 nano particle is well attached, and dispersed on the PMMA particle surface. Results indicate that the absolute value of the zeta potential affects the stability of SiO2 dispersion.