• 폴리머
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• 제28권5호
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• pp.374-381
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• 2004

제올라이트 분말을 첨가한 저밀도 폴리에틸렌 (LDPE) 복합 필름의 $CO_2,\;O_2,\;N_2$에 대한 기체 투과성을 조사하였다. 제올라이트 첨가 필름은 금속 양이온 혹은 계면 활성제로 표면 개질한 제올라이트 분말을 $20 wt\%$ 함유하는 LDPE 마스터배치를 제조한 후 이를 LDPE 수지와 용융혼합하여 중공필름 성형법으로 제조하였다. 최종적으로 제올라이트 분말이 0, 3, 5, 10 wt$\%$ 함유된 복합 필름을 얻었으며 이를 기체 투과도 측정에 사용하였다. 필름의 기체 투과성은 부피측정법에 기초한 기체 투과도 측정장치를 제작하여 분석하였다. 모든 경우에 있어 제올라이트 함량이 증가함에 따라 기체 투과도는 감소한 후 점차 증가하는 경향을 보여주었다. 계면 활성제로 표면 개질한 제올라이트 입자는 매트릭스 수지와의 계면 접착력을 향상시켰지만 표면 개질 이온의 종류에 따른 필름의 기체 투과 특성에는 뚜렷한 차이가 나타나지 않았다. 제올라이트 첨가 필름의 경우 각 기체의 투과도에 대한 온도 의존성의 차이는 순수 LDPE 필름에 비해 다소 작게 나타났다.

• 한국세라믹학회지
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• 제34권7호
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• pp.747-757
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• 1997

ZSM-5 zeolite composite membranes have been synthesized from a silica sol solution containing TPABr as an organic template by the dip-coating and the pressurized-coating hydrothermal treatment techniques. The CO2 separation efficiency of synthesized composite membranes was also investigated. The permeation mechanism of CO2 through ZSM-5 membranses was the surface diffusion, and that of N2, O2, and He gases was Knudsen diffusion or activated diffusion depending on the synthetic method of membranes and the measurement temperature. The CO2/N2 separation factor of the membrane prepared by the dip-coating hydrothermal treatment was 2.5 at about 12$0^{\circ}C$, while the ZSM-5 composite membrane synthesized by the pressurized-coating hydrothermal treatment technique showed the CO2/N2 separation factor of 9.0 at room temperature higher than that ever reported in the literature.

• Bulletin of the Korean Chemical Society
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• 제19권5호
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• pp.530-533
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• 1998

Chemical vapor deposition of $TiCl_4$ followed by the hydrolysis thereof at elevated temperatures was employed for the formation of $TiO_2$ clusters inside ZSM-5 matrix. BET and XRD revealed that the zeolite structure remains intact. XPS, Raman, FTIR, and UV-VIS reflectance spectroscopy indicated that $TiO_2$ particles thus formed are extremely small and localized inside the zeolite matrix.

• 한국세라믹학회지
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• 제33권9호
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• pp.1064-1072
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• 1996

The synthetic conditions and characteristics of ZSM-5 type zeolites (ZSM-5/silicalite) for the preparation of the zeolite composite membranes for gas separation were investigated. ZSM-5 zeolites could be synthesized by the hydrothermal treatment of the mixture of colloidal silica sol aluminum nitrate sodium hydroxide and TPABr at a temperature range of 150-17$0^{\circ}C$ in the autoclave. Silicalties were done from the solution of water glass water and TPABr. Their crystalline structures transformed from orthorhombic to monoclinic from and their pore structures of three-dimensional channels were opened as TPABr filling channels was burned off at the calcination temperature of 50$0^{\circ}C$. The specific surface area of the calcined zeolite was about 360 m3/g and its surface property was hydrophobic. Crystal sizes of ZSM-5 and silicalite were 0.5-1.0${\mu}{\textrm}{m}$ and 8-10${\mu}{\textrm}{m}$ respectively having no change due to the calcination. In particular the shape and the size of the ZSM-5 type zeolite were sensitively varied with silica sources and concentrations of reaction solutions/sols.

• Korean Chemical Engineering Research
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• 제49권5호
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• pp.588-593
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• 2011

미립담체에 고정된 Vero 세포를 이용한 돼지유행성설사병 바이러스 백신의 생산성을 향상시키기 위하여 Phillipsite-Gismondine synthetic zeolite가 투석막에 충진된 Carberry type 생물반응기를 사용하여 암모늄 이온을 선택적으로 흡착하였다. Impeller shaft 및 흡착제 사이에 응집된 미립담체 때문에 세포 성장이 감소하는 것으로 보이나, 포도당 소모량과 젖산 생성량의 비교를 통해 판단 할 때 zeolite는 세포에 독성을 나타내지 않았다. 배양배지로부터 암모늄 이온을 제거함으로써 세포성장 및 바이러스 생산 두 단계 모두가 크게 개선되었다. 바이러스 생산에 있어서는 암모늄 이온 제거에 의해 대조군과 비교하여 바이러스 역가가 2배 이상 향상되었다. 연구결과 zeolite는 암모늄 이온을 효과적으로 흡착제거하여 바이러스 백신의 생산성을 높일 수 있는 이상적인 흡착제임을 확인하였다.

• 한국환경과학회지
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• 제27권5호
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• pp.299-308
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• 2018

The adsorption characteristics of Cu ions were studied using the zeolite Na-A synthesized from Jeju volcanic rocks. The effects of various operating parameters such as initial concentration of Cu ions, contact time, solution pH, and solution temperature were investigated in batch experiments. The adsorption of Cu ions by Na-A zeolite was fitted well by pseudo-second-order kinetics and the Langmuir isotherm model. The maximum adsorption capacity determined using the Langmuir isotherm model was 152.95 mg/g. In addition, the adsorption of Cu ions by zeolite Na-A was primarily controlled by particle diffusion model in comparison with the film diffusion model. As the temperature increased from 303 K to 323 K, ${\Delta}G^o$ decreased from -2.22 kJ/mol to -3.41 kJ/mol, indicating that the adsorption of Cu ions by Na-A zeolite is spontaneous process.

• 한국토양비료학회지
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• 제18권4호
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• pp.352-358
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• 1985

1~0.5mm모래로 충전(充塡)한 sand column을 통해서 Zeolite가 수직(垂直) 유실(流失)과 수리전도도의 변화(變化)에 미치는 양이온의 영향(影響)을 조사(調査)한 결과(結果)는 다음과 같다. 1. Zeolite의 유실량(流失量)의 정도(程度)는 Na->K->$NH_4-$ Zeolite 순이었고 Mg-과 Ca-Zeolite는 유실(流失)되지 않았다. 2. Zeolite의 수직유실(垂直流失)은 주로 입자(粒子)들의 분산(分散)에 기인(基因)하였으며 투과용액(透過溶液)이 0.01N 농도(濃度)의 염용액(鹽溶液)에서 증류수(蒸溜水)로 바뀔때 분산(分散)이 가장 잘 일어났다. 3. 수리전도도(水理傳導度)의 변화(變化)가 심한 column 일수록 Zeolite 유실량(流失量)이 많았다.

• 한국물환경학회지
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• 제25권5호
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• pp.750-757
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• 2009

The ammonium ion exchange characteristics of natural zeolite were investigated to remove ${NH_4}^+-N$. The effect of water temperature, particle size and competitive cation on the exchange capacity was examined. Ammonium ion exchange capacity tended to decrease when the temperature increased from $25^{\circ}C$ to $40^{\circ}C$. Exchange capacity was increased according to the particle size of natural zeolite comes to be small. Batch isotherm experiments were conducted for measuring ammonium ion exchange capacity. The ion exchange capacity was well described either by the Langmuir isotherm model or by the Freundlich isotherm model. The ammonium ion exchange capacity ($q_m$) of zeolite carrier can be calculated $11.744mg-{NH_4}^+/g$-carrier. The ion exchange capacity of manufactured zeolite carrier was showed a similar tendency as ion exchange capacity of powder-sized natural zeolite. Therefore, zeolite carrier can be used for increasing of nitrogen removal efficiency in the wastewater treatment plants.

• 환경위생공학
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• 제12권3호
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• pp.61-71
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• 1997

This study was conducted to examine the adsorption capacity of $NH_{3}-N$ by natural zeolite for the purpose of investigating the possibility for $NH_{3}-N$ eliminator of korea natural zeolite. The dominant clay minerals of zeolite was clinoptiloite. The amount of $NH_{3}-N$ adsorption by zeplite was not significantly affected by the particle size of zeolite and increased with increasing the ratio of zeolite to the volume of solution. Removal ratio of 100% of NH$_{3}$-N by non, 1st, 2nd regenerated cloumn was continued separately during 4.5, 18, 30hr and this amount was each 0.081, 0.324, 0.540g $NH_{3}-N/zero$.100g. The eluenting amount of K, Ca, Mg was increased on the zeolite cloumn according to that of Na decreased. The amount of 74% of $NH_{3}-N$ was desorved on the zeolite cloumn for regenerating treatment during 8hr. The perfect removal amount was $0.216gNH_{3}-N/zero$.100g on the zeolite cloumn with field sample.

• Advances in materials Research
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• 제13권2호
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• pp.103-114
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• 2024

Zeolites are microporous materials that find applications in different fields due to their numerous interesting properties. This research investigated the effect of leaching on unheated Ifon kaolin in dilute hydrochloric acid and sulphuric acid. The hydrothermal method synthesized zeolite-X type, and the resulting sample was characterized using different techniques. The silica/alumina ratio in the synthesized sample was approximately 5.6, while Infrared spectra confirmed that the synthesized material was Zeolite-X. Based on the X-ray diffraction patterns, other phases were also formed in addition to zeolite-X crystals. Thermogravimetry results indicated that the synthesized zeolite was relatively stable below 500℃, so its weight loss was only 13% after heating to about 200℃. A differential thermal analyzer confirmed this amount of weight loss, and endothermic and exothermic reactions were also observed for the samples calcined respectively at 700 and 900℃. Based on Brunauer-Emmett-Teller (BET) analyses, samples at 700℃ showed slower adsorption-desorption isotherms, pore volume, and sizes than those at 900℃. These results have shown that leaching and calcination temperature significantly affect the type of zeolite produced.