• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.248-248
• /
• 2012

인산염을 기초로 한 다양한 촉매 기질의 합성과 더불어, 촉매활성를 가지는 여러 가지 전이 금속을 이러한 기질에 도입한 다양한 이종상 촉매가 개발되어 왔다. 우리는 phosphoric acid 와 zirconyl chloride을 이용하여 간단한 방법으로 ${\alpha}$-zirconium phosphate (Zr(HPO4)2.H2O)을 합성하였다. Phosphoric acid의 농도 변화에 따른 crystallinity의 변화를 XRD를 통해 분석하였고, FE-SEM을 통하여 형태를 확인 하였다. 특히, 합성한 각각의 생성물을 다양한 종의 amine을 이용하여 intercalation 반응을 수행하였다. 이를 XRD, TEM을 통하여 결정 구조 변화를 확인 하였고, 더 나아가 잠재적 촉매로서의 응용성을 연구할 예정이다.

• 한국분말재료학회지
• /
• 제9권5호
• /
• pp.336-340
• /
• 2002

The $\alpha$-zirconium phosphate particles as fine as 20 nm were fabricated through solution technique using $ZrOCl_2{\cdot}8H_2O$ and $H_3PO_4$ as precursors. Stability of $\alpha$-Zirconium phosphate could be ensured by adding excess phosphoric acid to a stoichiometric composition Instead of using reflux route that resulted in coarsening of particles due to an inevitably long aging. The excess phosphorous incorporated in the crystal could be successfully eliminated afterwards through careful washing. Moreover, heavily agglomerated particles are observed before washing, but fairly dispersed state is found out after washing treatment. Thus, it is found that dispersed state as well as phase stability is ensured through proper washing treatment.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2001년도 추계학술강연 및 발표대회
• /
• pp.53-53
• /
• 2001

• 한국재료학회지
• /
• 제34권5호
• /
• pp.247-253
• /
• 2024

The separation of zirconium and hafnium using tributyl phosphate (TBP)-Dodecane extractants in nitric acid medium was performed. Zirconium oxychloride, used as extraction feed, was obtained from the synthesis of Kalimantan zircon sand concentrate smelted using NaOH. The extraction process was carried out by dissolving chloride-based metals in nitric acid media in the presence of sodium nitrate using TBP-Dodecane as an extractant. Some of the extraction parameters carried out in this study include variations in organic phase and aqueous phase (O/A), variations in contact time, and variations in nitric acid concentration. Extraction was carried out using a mechanical shaker according to the parameter conditions. X-ray fluorescence (XRF) was used for elemental (Zr and Hf) composition analysis of the aqueous solution. The results showed that zirconium was separated from hafnium at optimum conditions with an organic/aqueous ratio of 1:5, contact time of 75 min, and an HNO₃ concentration of 7 M. The resulting separation factor of zirconium and hafnium using TBP-Dodecane was 14.4887.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2004년도 춘계 총회 및 학술발표회
• /
• pp.199-202
• /
• 2004

DMFC 성능을 개선시키기 위한 연구의 큰 영역은 고분자전해질막에 있으며 methanol crossover에 대한 영향을 최소화시킬 수 있는 소재개발이 우선적으로 요구되는 실정이다. 이러한 문제의 해결을 위해 Pivovar와 Cussler [1] 등은 투과증발 막분리공정에서 메탄올 저항체로 잘 알려진 폴리비닐알콜(poly vinyl alcohol, PVA)를 이용한 전해질막 연구를 하였다.(중략)

• 한국염색가공학회지
• /
• 제23권4호
• /
• pp.257-262
• /
• 2011

The dish cloth requires antimicrobial activity for hygienic purpose. Until now, organic antimicrobial agents of low cost have been frequently used for the anitimicrobial finishing. However, a cleaner hving anitimicroial activity should be more durable considering consumers' ever-increasing expectation. In this study, the cleaner containing the bamboo fiber were finished with a formulation of a new zirconium-containing inorganic agent of zirconium phosphate and polyurethane binders. The optimum treatment condition was investigated. And its durability against repeated laundering cycles was assessed. The existence of Zr after the repeated laundering was verified and the antimicrobial effect did not decrease under 30 washing cycles.

• 한국물환경학회지
• /
• 제21권6호
• /
• pp.637-642
• /
• 2005

The focus of this study was to examine the phosphorus removal characteristic by zirconium mesoporous structured material synthesized on various conditions. The zirconium sulfate-surfactant mesoporous structured material(ZS) was synthesized by hydro-thermal synthesis. The material has regular hexagonal array of surfactant micelles and sulfate ion ($HSO_4{^-}$). We confirmed that sulfate ion in zirconium mesoporous structured material can be ion-exchanged with phosphate ion ($H_2PO_4{^-}$) in phosphoric acid solution. On the X-ray diffraction (XRD) pattern of ZS, three peaks which shows the important characteristics of hexagonal crystal lattice were observed at (100), (110) and (200). The transmission electron micrograph (TEM) show high crystallization with pore size about $47{\AA}$. The maximum adsorption capacity of ZS was as great as 3.2 mmol-P/g-ZS. From the adsorption isotherm, correlation coefficients were higher for the Langmuir isotherm than the Freundlich isotherm. With the respect of chain length of surfactant, the adsorption capacity for phosphate synthesized with C12 was higher than C16 and C18. The highest amount of adsorbed phosphate on ZS was observed at the surfactant-to-zirconium molar ratio of 0.5 to 1.

• 공업화학
• /
• 제31권5호
• /
• pp.495-501
• /
• 2020

In this study, zirconium fumarate of metal-organic framework (MOF-801) was solvothermally synthesized at 130 ℃ and characterized through powder X-ray diffraction (PXRD) analyses and porosity measurements from N₂ sorption isotherms at 77 K. The ability of MOF-801 to act as an adsorbent for the phosphate removal from aqueous solutions at 25 ℃ was investigated. The phosphate removal efficiency (PRE) obtained by 0.05 g/L adsorbent dose at an initial phosphate concentration of 60 ppm after 3 h was 72.47%, whereas at 5 and 20 ppm, the PRE was determined to be 100% and 89.88%, respectively, after 30 min for the same adsorbent dose. Brunauer-Emmett-Teller (BET) surface area and pore volume of the bare MOF-801 sample were 478.25 ㎡/g and 0.52 ㎤/g, respectively, whereas after phosphate adsorption (at an initial concentration of 60 ppm, 3 h), the BET surface area and pore volume were reduced to 331.66 ㎡/g and 0.39 ㎤/g, respectively. The experimental data of kinetic (measured at initial concentrations of 5, 20 and 60 ppm) and isotherm measurements followed the pseudo-second-order kinetic equation and the Freundlich isotherm model, respectively. This study demonstrates that MOF-801 is a promising material for the removal of phosphate from aqueous solutions.

• 대한화학회지
• /
• 제63권1호
• /
• pp.37-44
• /
• 2019

N,N'-bis(ethyldihydrogen phosphate)-1,4,5,8-naphthalene bis(dicarboximide) (EPNI) and N,N'-bis(ethyldihydrogen phosphate)-3,4,9,10-perylene bis(dicarboximide) (EPPI) and their zirconium bisphosphate multilayers (Zr-EPNI and Zr-EPPI), that had been briefly reported by us, were further investigated in terms of their electrochemical properties. EPNI in aqueous solution showed typical two reversible reductions at ITO electrode but the reductions were strongly dependent on solution pH while EPPI showed only an irreversible reduction. The single and mixed multilayers of Zr-EPNI and Zr-EPPI were well constructed on ITO electrode by the alternate adsorptions of zirconium ion and the bisimides. While Zr-EPNI multilayer on ITO electrode showed single broad reversible reduction with $E_{1/2}=-0.68V$, Zr-EPPI gave two separated reductions at $E_{1/2}=-0.54$ and -0.81 V vs SCE, quite differently from the solution properties. The average layer densities of the multilayers were estimated as $1.5{\times}10^{-10}$ and $2.3{\times}10^{-10}mol/cm^2$ for Zr-EPNI and Zr-EPPI, respectively. Both the monolayers of Zr-EPNI and Zr-EPPI could not completely block the electron transfer between $Fe(CN){_6}^{3-}$ in solution and ITO electrode but 3-5 layers of Zr-EPNI and Zr-EPPI could block it completely and mediated the one-way electron transfer at the potential shifted to their reduction potentials. When the monolayer of zirconium 1,10-decanediylbisphosphonate (Zr-DBP) was used as a sublayer of Zr-EPNI and Zr-EPPI layers, the mediated electron transfer became prominent without any direct electron transfer.

• 대한환경공학회지
• /
• 제28권6호
• /
• pp.583-587
• /
• 2006

본 연구에서는 지르코늄 메조구조체를 인 흡착제로 사용함에 있어, 구조체 합성에 사용된 지르코늄 무기물과 계면활성제의 몰비와 계면활성제의 종류가 지르코늄 메조구조체의 인 흡착능 및 흡착속도에 미치는 영향을 평가하였다. 이를 위해, 무기물/계면활성제의 비율 및 계면활성제의 종류를 달리하여 지르코늄 메조구조체를 합성하고 X선 회절분석을 통해 구조적 특성을 파악하였으며, 등온흡착과 kinetic 실험을 수행하여 흡착해석모델을 적용한 뒤 각 특성상수를 비교하였다. 결과적으로, 지르코늄 메조구조체를 합성함에 있어 무기물/계면활성제의 몰비를 1/0.50($0.013{\cdot}Zr(SO_4){_2}:0.068{\cdot}surfactant:5.55{\cdot}H_2O$)로 하는 경우 가장 규칙적이고 뚜렷한 형태의 메조기공을 가지는 구조체를 얻을 수 있고, 이로부터 인에 대한 흡착능과 흡착속도를 최대로 할 수 있음을 알 수 있었다. 또한 계면활성제의 탄소체인이 길어짐에 따라 구조체의 기공크기가 커짐을 알 수 있었고, 본 실험에 사용된 계면활성제중 dodecyltrimethylammonium bromide을 형판으로 지르코늄 메조구조체를 합성할 경우 인에 대한 흡착능과 흡착속도를 최대로 할 수 있음을 알 수 있었다.