• Title/Summary/Keyword: Phosphoric acid

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Fabrication of Porous Calcium Phosphate by Using a Pre-Form of Nature Material (자연물의 미세구조를 활용한 다공성 인산칼슘 제조)

  • Lee, Sang-Jin;Lee, Hoon-Cheol
    • Journal of the Korean Ceramic Society
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    • v.47 no.3
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    • pp.244-248
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    • 2010
  • Porous calcium phosphates were successfully fabricated by using a cuttlefish bone. The cuttlefish bone, which is composed of $CaCO_3$, showed a special porous microstructure containing uniform-sized voids. In this study, the pre-forms infiltrated distilled phosphoric acid were sintered at $1200^{\circ}C$ in an air atmosphere. The porous microstructure of the pre-forms was kept their original pattern after sintering with a synthesis of calcium phosphate. The obtained porous calcium phosphate, sintered at $1200^{\circ}C$ for 3 h at 17% concentration of phosphoric acid, showed uniform open pores of 150 ${\mu}m$ in size and $\beta$-TCP phase in the XRD patterns. Above 16% concentration, CaO phase, derived from the decomposition of $CaCO_3$, decreased gradually in the sintered samples, and the measured Ca/P ratios of the samples prepared from 16% and 18% concentration were 1.67 and 1.43, which are close to stoichiometric HA (1.66) and $\beta$-TCP (1.50).

Preparation of Solid-Phase Extractant by Immobilizing Di-(2-ethylhexyl)phosphoric Acid (D2EHPA) and Tri-butyl-phosphate (TBP) in Polysulfone and Removal Characteristics of Cu(II) (Polysulfone에 추출제 Di-(2-ethylhexyl)phosphoric acid (D2EHPA)와 tri-butyl-phosphate(TBP)를 고정화한 고체상 추출제의 제조와 Cu(II)의 제거 특성)

  • Kam, Sang-Kyu;Jeon, Jin-Woo;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.24 no.1
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    • pp.1-7
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    • 2015
  • The solid-phase extractant PS-D2EHPA/TBP was prepared by immobilizing two extractants D2EHPA and TBP in polysulfone (PS). The prepared PS-D2EHPA/TBP was characterized by using fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The removal of Cu(II) from aqueous solution was investigated in batch system. The experiment data were obeyed the pseudo-second-order kinetic model. Equilibrium data were well fitted by Langmuir model and the removal capacity of Cu(II) by solid extractant PS-D2EHPA/TBP obtained from Langmuir model was 3.11 mg/g at 288 K. The removal capacity of Cu(II) was increased according to increasing pH from 2 to 6, but the removal capacity was decreased below pH 3 remarkably.

Fabrication and Characterization of AAO Template with Variation of the Phosphoric Acid Amount of the Etching Solution (에칭용액의 인산 첨가량에 따른 양극산화 알루미늄 템플레이트의 제작 및 특성)

  • Jo, Ye-Won;Kim, Yong-Jun;Yeo, Jin-Ho;Lee, Sung-Gap;Kim, Young-Gon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.7
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    • pp.448-451
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    • 2014
  • Anodic aluminum oxides (AAO) fabricated by the two-step anodizing process have attracted much attention for the fabrication of nano template because of pore structure with high aspect ratio, low cost process and ease of fabrication. AAOs are characterized by a homogeneous morphology of parallel pores that grow perpendicular to the template surface with a narrow distribution of diameter, length and inter-pores spacing, all of which can be easily controlled by suitably choosing of the anodizing parameters such as pH of the electrolyte, anodizing voltage and duration of anodizing. In this study, AAO templates were characterized by X-ray diffraction and field-emission scanning electron microscope (FE-SEM). The dependence of the pore size change according to the amount of addition of phosphoric acid, which was used to remove the initial alumina oxide layer, was not observed.

The adsorption-desorption behavior of strontium ions with an impregnated resin containing di (2-ethylhexyl) phosphoric acid in aqueous solutions

  • Kalal, Hossein Sid;Khanchi, Ali Reza;Nejatlabbaf, Mojtaba;Almasian, Mohammad Reza;Saberyan, Kamal;Taghiof, Mohammad
    • Advances in environmental research
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    • v.6 no.4
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    • pp.301-315
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    • 2017
  • An Amberlite XAD-4 resin impregnated with di(2-ethylhexyl)phosphoric acid was prepared and its adsorption-desorption behaviors with Sr(II) ions under various conditions was examined. The resin was characterized by fourier transform infrared and thermal analysis techniques. The effects contact time, temperature, pH, interfering ions and eluants were studied. Results showed that adsorption of Sr (II) well fitted with pseudo-second-order kinetic model. The equilibrium adsorption data of Sr (II) on the impregnated resin were analyzed by Jossens, Weber-van Vliet, Redlich-Peterson and Fritz-Schlunder models to find out desirable equilibrium condition. Among them, the Fritz-Schlunder model best fitted to the experimental data. The maximum sorption capacity of impregnated resin amounted to 0.45 mg/ g at pH 8.0 and $20^{\circ}C$.

Removal Characteristics of Sr(II) by Solid-Phase Extractant Prepared by Immobilizing Di-(2-ethylhexyl)phosphoric acid (D2EHPA) and Tri-butyl-phosphate (TBP) in Polysulfone (Polysulfone에 Di-(2-ethylhexyl)phosphoric acid(D2EHPA)와 tri-butyl-phosphate(TBP)를 고정화하여 제조한 고체상 추출제에 의한 Sr(II)의 제거특성)

  • Kam, Sang-Kyu;Jeon, Jin-Woo;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.24 no.3
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    • pp.267-274
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    • 2015
  • The feasibility of PS-D2EHPA/TBP beads prepared by immobilizing two extractants D2EHPA and TBP in polysulfone to remove Sr(II) from aqueous solution was investigated in batch system. Batch experiments were carried out to study equilibrium isotherms, kinetics, and thermodynamics. Equilibrium data were fitted using Langmuir, Freundlich, Redlich-Peterson, and Dubinin-Radushkevich equation models at temperatures of 298 K, 313 K, and 328 K. The removal capacity of Sr(II) by PS-D2EHPA/TBP beads obtained from Langmuir model was 2.41 mg/g at 298 K. The experimental data were well represented by pseudo-second-order model. The removal process of Sr(II) by PS-D2EHPA/TBP beads prepared in this study was found to be feasible, endothermic, and spontaneous.

Removal Characteristics of Cu(II) by PSf/D2EHPA/CNT Beads Prepared by Immobilization of Carbon Nanotubes (CNT) and Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) on Polysulfone (PSf) (Polysulfone으로 carbon nanotubes (CNT)와 di-(2-ethylhexyl)-phosphoric acid (D2EHPA)를 고정화한 PSf/D2EHPA/CNT 비드에 의한 Cu(II)의 제거특성)

  • Lee, Chang-Han;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.25 no.11
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    • pp.1485-1491
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    • 2016
  • PSf/D2EHPA/CNT beads were prepared by immobilizing di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and carbon nanotubes (CNT) on polysulfone (PSf) and used to remove Cu(II) from aqueous solutions. Optimum pH was in the range of 4 to 6. The removal kinetic of Cu(II) by the prepared PSf/D2EHPA/CNT beads was mainly governed by internal diffusion, and the diffusion coefficient of Cu(II) by PSf/D2EHPA/CNT beads was found to be $2.19{\times}10^{-4}{\sim}2.64{\times}10^{-4}cm^2/s$. The Langmuir isotherm model predicted the experimented data well. The maximum removal capacity of Cu(II) obtained from this isotherm was 7.32 mg/g. Calculated thermodynamic parameters such as ${\Delta}G^o$, ${\Delta}H^o$ and ${\Delta}S^o$ showed that the adsorption of Cu(II) ions onto PSf/D2EHPA/CNT beads was feasible, spontaneous and endothermic at 293-323 K.

Studies on the Stabilization of Rayon Fabrics for Preparing Carbon Fabrics: 2. Fast Isothermal Stabilization Processes at High Temperature

  • Yoon, Sung-Bong;Cho, Chae-Wook;Cho, Dong-Hwan;Park, Jong-Kyoo;Lee, Jae-Yeol
    • Carbon letters
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    • v.9 no.4
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    • pp.308-315
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    • 2008
  • In the present study, fast isothermal stabilization processes for rayon precursor fabrics were performed at $350^{\circ}C$ and $400^{\circ}C$ within 3 minutes and the chemical and physical characteristics of the stabilized fabrics were investigated. In addition, rayon precursor fabrics were pre-treated with three different phosphorous-based flame retardants and then stabilized. The effect of flame retardants on the chemical composition, thermal shrinkage, weight change, thermal stability and XRD results was examined, comparing with those of the precursor fabrics. The result showed that the stabilization of rayon fabrics was most effective as the stabilization temperature was $350^{\circ}C$, the stabilization time was 3 min, and the pre-treatment with phosphoric acid of 1 vol%. The carbon contents of stabilized rayon fabrics were increased with increasing stabilization temperature and time, whereas the oxygen contents were decreased. Also, it is likely that the pre-treatment with phosphoric acid plays a role in retarding the change of chemical structure of rayon fabric. The XRD result was quite consistent with the result showing the effect of phosphoric acid on the chemical composition, thermal shrinkage and weight reduction of rayon fabric.

Effect of Microbial Fertilizers on Yield of Young Radish(Raphanus sativus L.)

  • 김경제;김수정
    • Korean Journal of Organic Agriculture
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    • v.9 no.3
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    • pp.103-117
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    • 2001
  • This study was inducted to investigate the effects of microbial fertilizers on the fields of young radish(Raphanus sativus L.), chemical components of plant and soil, and the microbial floras. Six microbial fertilizers, MPK+Husk+Palma, Husk+Palma, MPK+Compost, Compost, BIO Livestock Clean System(BLCS) cattle dropping, and Tomi were used. The yields of young radish were increased in six microbial fertilizer treatments. The fresh matter weight, the number of leaves, and the dry matter weight of young radish in BLCS cattle dropping treatment, the leaf length in MPK+Husk+Palma treatment, the sugar content in Husk+Palma treatment, arid the leaf width in Tomi treatment showed the highest amount, respectively. The effects of microbial fertilizers on chemical characteristics of young radish and soil were examined. Phosphoric acid amount of young radish in Tomi treatment was much higher than other treatments. Potassium amount of young radish showed high significance in all microbial fertilizer treatments compared with control, and shoved the highest in Compost treatment . Two components, phosphoric acid find potassium, in soil inoculated by microbial fertilizers showed significant. Phosphoric acid in the Tomi treatment and Potassium in Husk+Palma treatment were increased. The microorganic populations in soil inoculated with microbial fertilizers were examined. While the number of Bacillus in ceil was increased in MPK+Husk+Palma treatment, the numbers of total bacteria, actinomycetes, and fungi were increased in Tomi treatment.

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Quantitative Analysis of the Amount of Aluminium Dissolved in Phosphoric Acid

  • Moon, Sungmo;Yang, Cheolnam
    • Journal of the Korean institute of surface engineering
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    • v.50 no.4
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    • pp.231-236
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    • 2017
  • The present work addresses how to measure the amount of dissolved aluminum in phosphoric acid, based on volumetric and gravimetric measurements of the precipitates formed by reaction between the $H_3PO_4$ solution containing dissolved aluminum ions and 10 % KF solution. The volume of the precipitates increased with dilution of the dissolved aluminum-containing $H_3PO_4$ solution up to 1/4 dilution above which it decreased with further dilution. The lowered amounts of the precipitates at low dilution less than 1/4 and high dilution more than 1/4 are attributed to high acidity of the solution and decreased amount of dissolved aluminum in the solution, respectively. Volumetric measurement of the amount of precipitates was found not to be very reliable with the experiments, while weight measurement of the precipitates after drying for 80 min at $60^{\circ}C$ appeared to be very reproducible. In the present work, it is suggested that the amount of Al dissolved in 85 % $H_3PO_4$ solution can be calculated by multiplying 50 to the weight of precipitate obtained by reacting 8 ml of 1/4 diluted $H_3PO_4$ solution containing dissolved aluminum ions with 6 ml of 10 % KF solution.

Phosphoric Acid Modified Nb2O5: A Selective and Reusable Catalyst for Dehydration of Sorbitol to Isosorbide

  • Tang, Zhen-Chen;Yu, Ding-Hua;Sun, Peng;Li, Heng;Huang, He
    • Bulletin of the Korean Chemical Society
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    • v.31 no.12
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    • pp.3679-3683
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    • 2010
  • Niobium oxide ($Nb_2O_5$) and phosphated $Nb_2O_5$ were synthesized and used as catalysts for sorbitol dehydration to isosorbide. The characterization results of $N_2$ adsorption, XRD and $NH_3$-TPD revealed that the phosphoric acid modification could well prevent the crystallization of $Nb_2O_5$. And the amorphous phosphated $Nb_2O_5$ catalysts kept the relatively large surface area and stable acidity at high calcination temperature. The catalytic results showed that the selectivity to isosorbide could be dramatically enhanced over phosphated $Nb_2O_5$. The excellent catalytic performance with 100.0% sorbitol conversion and 62.5% isosorbide selectivity were obtained over the 0.8P/NBO-400 catalyst. Comparing with $Nb_2O_5$ catalysts, phosphated $Nb_2O_5$ catalysts regenerated through a simple calcination process showed no significant activity loss after recycling three runs.