• 자원리싸이클링
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• 제28권2호
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• pp.54-61
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• 2019

블랙드로스로부터 고순도 알루미나를 회수하기 위해 기계적 활성화 처리한 블랙드로스를 수산화나트륨용액으로 침출하면 미량의 규소(IV)가 함유된 알루미네이트 용액을 얻을 수 있다. 본 연구에서는 hydrotalcite를 사용하여 알루미늄(III)과 규소(IV)의 농도가 각각 13000과 150 mg/L인 5 M의 수산화나트륨용액에서 규소(IV)의 선택적 흡착거동에 대하여 조사했다. Hydrotalcite는 수산화나트륨용액으로부터 규소(IV)만을 선택적으로 흡착하였다. Hydrotalcite의 소성과 농도 및 NaOH의 농도가 규소(IV)의 흡착에 미치는 영향을 조사하였다. 5 M의 수산화나트륨용액에서 규소(IV)의 흡착률은 낮으나 물로 48배 희석하여 소성한 hydrotalcite의 농도가 4.5 g/L 이상인 조건에서 규소(IV)를 대부분 흡착시켜 고순도 알루미나용액을 회수할 수 있었다. 소성한 hydrotalcite에서 규소(IV)의 흡착은 Freundlich 등온흡착식과 잘 일치하였다.

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2029-2033
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• 2007

Hydrotalcite, layered double hydroxides (LDH), with hexagonal morphology has been rapidly synthesized by microwave reaction within 1 hour by urea hydrolysis from homogeneous solution. Different synthesis parameters, Mg/Al molar ratio, microwave reaction temperature and microwave power were systematically investigated. Pure hydrotalcite phase was obtained for Mg/Al ratios of 2:1 and 3:1, and higher reaction temperature gave higher crystallinity. The hydrotalcite synthesized at 600W power shows the highest crystallinity and more homogeneous crystal size distribution. The hydrotalcite samples were characterized by powder X-ray diffraction (XRD), simultaneous thermogravimetric/differential thermal analysis (TG/DTA), Fourier Transform Infrared (FT-IR) and Scanning electron micrograph (SEM).

• Journal of Pharmaceutical Investigation
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• 제25권4호
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• pp.331-338
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• 1995

In order to screen appropriate preservatives for the suspension containing sucralfate, neusilin and hydrotalcite, the patterns and mechanism of the adsorption and desorption of several preservatives on these antacids were studied. The employed preservatives were parabens(methyl, propyl, butyl), chlorhexidine diacetate and sorbic acid. While none of parabens were adsorbed on three antacids, chlorhexidine diacetate was strongly adsorbed on all the antacids employed, especially on hydrotalcite. Sorbic acid was not adsorbed on neusilin and hydrotalcite, however, 65% of sorbic acid was adsorbed on sucralfate. The adsorption of chlorhexidine diacetate on neusilin and hydrotalcite was partly physical and partly chemical, while its adsorption on sucralfate was almost chemical. Sorbic acid was completely deserted from sucralfate. In all cases, the adsorption isotherms were fitted well to both Freundlich equation and Langmuir equation. Based on these results, parabens and sorbic acid were the preservatives of choice for the suspension containing sucralfate, neusilin and hydrotalcite.

• 한국염색가공학회지
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• 제31권3호
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• pp.177-186
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• 2019

In this study, we investigated for synthetic hydrotalcite in chloroprene rubber foam. Experiments were carried out to find the optimum content ratio by controlling the contents of MgO and Hydrotalcite. Swelling test in toluene immersion was made to measure the crosslinking density of CR foams, and the cure properties were investigated with flat die rheometer and Mooney viscosity. The difference of hardness, tensile strength and elongation at break were observed after immersing in 7% NaCl or 21% NaCl solutions for a day and four days. In addition, the volume change and water content remaining in CR foam were measured after immersing NaCl solution. As content of MgO increased, the value of the cure torque tended to increase, but it was almost constant above 2phr of MgO. However, the Mooney viscosity decreased with increasing MgO content. The crosslinking density, determined by the swelling ratio, showed that the CR compound without MgO showed a higher degree of swelling. When the content of hydrotalcite/MgO was 3:2, it was the lowest volume change of CR form. Also, As the content of hydrotalcite decreased, the difference of mechanical properties before and after immersion NaCl solution increased.

• 약학회지
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• 제45권1호
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• pp.23-28
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• 2001

Hydrotalcite was prepared by reacting with sodium carbonate, magnesium hydroxide and aluminum chloride solutions in this study. The optimum synthesis conditions based on the yield of the product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of hydrotalcite were as follows ; reacting temperature : 63~9$0^{\circ}C$, concentration of reactant solution : 18.20~19.82%, molar concentration ratio of two reactants [Mg(OH)$_2$] / (AICl$_3$.6$H_2O$) : 6.0, temperature of washing water : 29.0-34.4$^{\circ}C$, drying temperature : 56-77.6$^{\circ}C$. The physicochemical properties of hydrotalcite as medicine were studied by use of chemical analysis, bulk volume test and acid consuming capacity measurements.

• 약학회지
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• 제43권6호
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• pp.689-695
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• 1999

Hydrotalcite was prepared by reacting with sodium carbonate, magnesium oxide and aluminum sulfate solutions in this study. The optimum synthesis conditions based on the yield of the product were established by applying Box-Wilson experimental design. It was found that the optimum synthesis conditions of hydrotalcite were as follows; reacting temperature : 48~63$^{\circ}C$, concentration of reactant solution : about 20%, molar concentration ratio of two reactants [MgO]/[Al. sulfate] ; 7.35~8.1, temperature of washing water : 34.4~37.4$^{\circ}C$, drying temperature : 74~81.5$^{\circ}C$. The physicochemical properties of hydrotalcite as medicine were studied by use of chemical analysis, D.S.C. thermogram, bulk volume test and acid consuming capacity measurements.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.149-152
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• 2009

Hydrotalcites are anionic clays that are quite prevalent in nature and their importance is growing more and more because of their very wide range of potential applications and uses. Understanding the structural and compositional changes that occur on the molecular scale during the thermal decomposition of hydrotalcite compounds is essential for the basic prediction and comprehensive understanding of the behavior and technical application of these materials. In this study, several hydrotalcite compounds calcined at different temperatures for applications in a chlorine resistant textile were prepared and 27-Aluminm solid-state nuclear magnetic resonance (NMR) spectroscopy was used as a tool to study their local structure and behavior. The changes in the Al coordination of the hydrotalcite compounds were investigated with one dimensional (1D) solid-state magic angle spinning (MAS) NMR spectroscopy. The two broad resonances arising from the structurally different Al coordinations of these compounds were clearly resolved by two dimensional (2D) triple quantum magic angle spinning (3QMAS) NMR spectroscopy.

• 한국자기공명학회논문지
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• 제11권1호
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• pp.42-47
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• 2007

Several hydrotalcite compounds calcined with different temperature for applications in a chlorine resistant textile were prepared, and its structural changes in dependence on the temperature were studied by using $^{27}Al$ solid-state nuclear magnetic resonance(NMR) spectroscopy. We found that the Al coordination was partly lowered from octahedral to tetrahedral site as the calcined temperature goes up. And we also investigated the hydrotalcite-treated textile for chlorine resistance by using $^{27}Al$ solid-state NMR spectroscopy.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 춘계학술대회
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• pp.93-93
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• 1995

The three combined products were prepared as suspended solutions composed of various ratio of Sucralfate, Hydrotalcite and Neusilin, into which 30% ethanol extracts of Machili cortex, and of Atractylodis rhizoma were added. The efficacy for these products was examined in vivo using a pyrous ligation method in rats. The influence of these products on the intestinal motility was also examined in mice. In all experimental setting, the antisecretory effect of the combined treatment was more pronounced than that of each drug alone. The combined treatment consisted of Sucralfate, Hydrotalcite, Neusilin ratios of 2:2:1 produced the highest inhibitory effect for the gastric secretion. The intestinal motility was not influenced significantly by the treatment of all experimental setting. The above results revealed that the therapeutic dose of Sucralfate, Hydrotalcite, Neusilin given in combination showed a synergistic effect for the inhibition of gastric secretion and little side effect on the intestinal motility. Therefore, the combined product with Sucralfate, Hydrotalcite, Neusilin ratio of 2:2:1 is recommended for the useful drug to heal the gastrointestinal diseases with no side effect on the intestinal motility.

• 한국수소및신에너지학회논문집
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• 제21권5호
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• pp.412-418
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• 2010

Steam reforming of n-hexadecane, a major component of diesel over Ni-based hydrotalcite-like catalyst was carried out at $900^{\circ}C$ at atmospheric pressure with space velocity of $10,000h^{-1}$ and feed molar ratio of steam/carbon=3.0. Ni-based hydrotalcite catalyst was prepared by a solid phase crystallization (spc) method and characterized by $N_2$-physisorption, CO chemisorption, TPR., XRD, and TEM techniques. It was found that spc Ni/MgAl catalyst showed higher catalytic stability and inhibition of carbon formation than Ni/$\gamma-Al_2O_3$ catalyst under the tested conditions. The results suggest that the modified spc-Ni/MgAl catalyst after optimization may be applied for the SR reaction of diesel.