• Title/Summary/Keyword: solution synthesis

검색결과 1,784건 처리시간 0.029초

TTIP/TEOA 혼합용액을 이용한 Au/TiO2 Core-Shell 구조 나노입자 합성 (Synthesis of Au/TiO2 Core-Shell Nanoparticles by Using TTIP/TEOA Mixed Solution)

  • 권현우;임영민;유연태
    • 한국재료학회지
    • /
    • 제16권8호
    • /
    • pp.524-528
    • /
    • 2006
  • On the synthesis of Au/$TiO_2$ core-shell structure nanoparticle, the effect of concentration of $Ti^{4+}$ and reaction temperature on the morphology and optical property of Au/$TiO_2$ core-shell nanoparticles is examined. A gold colloid was prepared by $HAuCl_4{\cdot}4H_2O\;and\;C_6H_5Na_3{\cdot}2H_2O$. Titanium stock solution was prepared by mixing solution of titanium(IV) isopropoxide (TTIP) and triethanolamine (TEOA). The concentrations of $Ti^{4+}$ stock solution were adjusted to $10.01{\sim}0.3$ mM, and then the gold colloid is added to the $Ti^{4+}$ stock solution. Au/$TiO_2$ core-shell structure nanoparticles could be prepared by the hydrolysis of the $Ti^{4+}$ stock solution at $80^{\circ}C$. The size of synthesized Au nanoparticles was 15 nm. The thickness of $TiO_2$ shell on the surface of gold particles was about 10 nm. The absorption peak of synthesized Au/$TiO_2$ core-shell nanoparticles shifted towards the red end of the spectrum by about 3 nm because of the formation of $TiO_2$ shell on the surface of gold particles. The good $TiO_2$ shell is produced when $Ti^{4+}$ concentration is varied between 0.01 and 0.05 mM, and reaction temperature is maintained at $80^{\circ}C$. The crystal structure of $TiO_2$ shell was amorphous.

규질 이암으로부터 제올라이트의 수열 합성에 관한 연구 (Hydrothermal Synthetic Study of Zeolites from Siliceous Mudstone)

  • 노진환
    • 한국광물학회지
    • /
    • 제13권4호
    • /
    • pp.171-185
    • /
    • 2000
  • Siliceous mudstones are embedded on a large scale in the Tertiary formations of Pohang area. Some useful zeolites such as NsP, (Na, TMA)P, analcime and hydroxysodalite were synthesized from the siliceous mudstones by treating with the variety of solution, i.e ., NaOH, NaOH+NaCl, NaOH, NaOH+$NaAlO_2$and NaOH+TMAOH at the low-temperature hydrothermal system ranging 60~12$0^{\circ}C$. Major precursor of zeolites is found as opal-CT in the zeolite-forming reaction. Smectite, which is included in considerable amounts in the mudstone, appears to play a major role of Al-source in the zeolite synthesis. In comparison, chalcedonic quartz and mica are rather insoluble in alkaline solution, and thus, these are observed as major impurities in the reaction products. An addition of $NaAlO_2$to NaOH solution is effective for eliminating these impurities in the reaction procedure, through these are partly dissolved when elevating the reaction temperature, concentration, and time. Phase change from NaP to hydroxysodalite takes place at the NaOH concentrations of 3.0~4.0 M, and the reaction is not sensitive to the temperature shift. NaP is more stable at lower NaOH concentration and higher activity of $Na_{+}$ whereas analcime is sensitive to the temperature change and stable at higher than $100^{\circ}C$ and 2.0~4.0 M in NaOH concentration. For the pure NaP synthesis without any other products, the treatment of mudstones with 1:1 solution of NaOH and $NaAlO _2$ turns out to be quite effective. NaP was successfully synthesized together with analcime at $100^{\circ}C$ as well as lower concentrations of NaOH+NaCl solution. In addition, the organic type, (Na, TMA)P was formed together with smectite in the 1:1 solution of NaOH and TMAOH.

  • PDF

유전자 알고리즘을 이용한 분할 버스 아키텍처의 상위 수준 합성 (A genetic-algorithm-based high-level synthesis for partitioned bus architecture)

  • 김용주;최기영
    • 전자공학회논문지C
    • /
    • 제34C권3호
    • /
    • pp.1-10
    • /
    • 1997
  • We present an approach to high-level synthesis for a specific target architecture-partitioned bus architecture. In this approach, we have specific goals of minimizing data transfer length and number of buses in addition to common synthesis goals such as minimizing number of control steps and satisfying given resource constraint. Minimizing data transfer length and number of buses can be very important design goals in the era of deep submicron technology in which interconnection delay and area dominate total delay and area of the chip to be designed. in partitioned bus architecture, to get optimal solution satisfying all the goals, partitioning of operation nodes among segments and ordering of segments as well as scheduling and allocation/binding must be considered concurrently. Those additional goals may impose much more complexity on the existing high-level synthesis problem. To cope with this increased complexity and get reasonable results, we have employed two ideas in ur synthesis approach-extension of the target architecture to alleviate bus requirement for data transfer and adoption of genetic algorithm as a principal methodology for design space exploration. Experimental results show that our approach is a promising high-level synthesis mehtodology for partitioned bus architecture.

  • PDF

Particle Size, Morphology and Color Characteristics of C.I. Pigment Red 57:1 : 1. Effect of Synthesis Conditions

  • Seo, Hee Sung;Lee, Hyun Kyung;Yoo, Eui Sang
    • 한국염색가공학회지
    • /
    • 제27권4호
    • /
    • pp.229-244
    • /
    • 2015
  • The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the "lake" formation resulting different particle aggregate size and color shade.

Solid-State Ball-Mill Synthesis of Prussian Blue from Fe(II) and Cyanide Ions and the Influence of Reactants Ratio on the Products at Room Temperature

  • Youngjin Jeon
    • 대한화학회지
    • /
    • 제68권2호
    • /
    • pp.82-86
    • /
    • 2024
  • This paper presents the solid-state synthesis of insoluble Prussian blue (Fe4[Fe(CN)6]3·xH2O, PB) in a ball mill, utilizing the fundamental components of PB. Solid-state synthesis offers several advantages, such as being solvent-free, quantitative, and easily scalable for industrial production. Traditionally, the solid-state synthesis of PB has been limited to the reaction between iron(II/III) ions and hexacyanoferrate(II/III) complex ions, essentially an extension of the solution-based coprecipitation method to solid-state reaction. Taking a bottom-up approach, a reaction is designed where the reactants consist of the basic building blocks of PB: Fe2+ ions and CN- ions. The reaction, with a molar ratio of Fe2+ and CN- corresponding to 1:2.8, yields PB, while a ratio of 1:6.6 results in a mixture of potassium hexacyanoferrate(II) (K4Fe(CN)6), potassium chloride (KCl), and potassium cyanide (KCN). This synthetic approach holds promise for environmentally friendly methods to synthesize multimetallic PB with maximum entropy in nearly quantitative yield.

Synthesis and Vibrational Spectroscopic Study of Selectively $3^1-^{18}O$-Labelled Chlorophyll Derivatives

  • Morishita, Hidetada;Tamiaki, Hitoshi
    • Journal of Photoscience
    • /
    • 제9권2호
    • /
    • pp.356-358
    • /
    • 2002
  • Regioselective 3$^1$-$^{18}$ O-labelling of chlorophyll derivatives possessing a 3-formyl group such as methyl (pyro) pheophorbide-d (3, 4) was carried out efficiently by a simple one-step procedure; by stirring a homogeneous solution of tetrahydrofuran and H$_2$$^{18}$ O containing a small amount of trifuluoroacetic acid.

  • PDF