• Title/Summary/Keyword: Nanosize

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Synthesis of nanosize $SiO_2$particles by a reverse micelle and sol-gel processing

  • Bae, Dong-Sik;Han, Kyong-Sop;James H. Adair
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.11 no.2
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    • pp.67-70
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    • 2001
  • Nanosize $SiO_2$composite particles have been synthesized within reverse micelle via metal alkoxide hydrolysis and condensation. The size of the particles can be controlled by manipulating the relative rates of the hydrolysis and condensation reactions of tetraethoxysilane (TEOS) within the microemulsion. The average size of synthesized particles was about in the size range 14~30nm. The effects of synthesis parameters, such as the molar ratio of water to TEOS, the molar ratio of water to surfactant, and the amount of base catalyst, are discussed.

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A Review of Nanostructured Ca-aluminate Based Biomaterials within Odontology and Orthopedics

  • Hermansson, Leif
    • Journal of the Korean Ceramic Society
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    • v.55 no.2
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    • pp.95-107
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    • 2018
  • This presentation will give an overview of Ca-aluminate based biomaterials and their proposed use within the field of nanostructured biomaterials. The paper describes typical features of Ca-aluminate materials with regard to technology, chemistry, biocompatibility including hemocompatibility and bioactivity, and developed microstructure. Special focus will be on the developed microstructure, which is in the nanosize range. Application possibilities within odontology, orthopedics, and drug delivery are presented. The nanostructure including pore size below 5 nm in these structures opens up this material for some use in specific dental-related applications in which antibacterial and bacteriostatic aspects are of importance, and as thin coating on implants within dental and orthopaedic applications. Nanosize porosity is essential in drug delivery systems for controlled release of medicaments. The priority field for Ca-aluminate biomaterials is implant materials, which use minimally-invasive techniques to offer in vivo, on-site developed biomaterials.

The growth of zinc oxide particles by coagulation in aerosol reactor (에어로졸 반응기에서 산화아연 입자의 응집 성장)

  • Lee, Jong Ho;Song, Shin Ae;Park, Seung Bin
    • Particle and aerosol research
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    • v.4 no.2
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    • pp.69-75
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    • 2008
  • Nanosize ZnO particles were prepared by oxidation of zinc vapor and the particle growth was modeled by a coagulation model by assuming that the characteristic time for reaction was much shorter than coagulation time and residence time (${\tau}_{reaction}{\ll}{\tau}_{coagulation}{\ll}{\tau}_{residence}$). Experimental measurement of zinc oxide particles diameter was consistent with the predicted result from the coagulation model. For practical purpose of predicting zinc oxide size in areosol reactor, the constant kernel solution is concluded to be sufficient, Uniqueness of nano-scale property of zinc oxide was confirmed by the higher photocatalytic activity of zinc oxide than nanosize titania particles.

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Effect of Seed Coating Layer on the Microstructure of NaA Zeolite Separation Layer Grown on ${\alpha}$-alumina Support (종결정 코팅층이 다공성 ${\alpha}$-알루미나 지지체 표면에 성장되는 NaA 제올라이트 분리층의 미세구조에 미치는 영향)

  • Kim, Min-Ji;Sharma, Pankaj;Han, Moon-Hee;Cho, Churl-Hee
    • Membrane Journal
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    • v.24 no.5
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    • pp.375-385
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    • 2014
  • NaA zeolite/${\alpha}$-alumina composite membranes were hydrothermally synthesized at $100^{\circ}C$ for 24 hr by using nanosize seed of 100 nm in diameter and an ${\alpha}$-alumina support of $0.1{\mu}m$ in pore diameter, and then effect of seed coating layer on the microstructure of NaA zeolite separation layer was systematically investigated. In cases when nanosize seed was coated with a monolayer, increment in seed coverage induced small grained and thick NaA zeolite separation layer. On the other hand, in case when nanosize seed was coated with a multilayer, much small grained and thick separation layer was formed. It was clear that an uniform monolayer seed coating is required to grow hydrothermally a thin and defect-free NaA zeolite separation layer. In the present study, it was clearly announced that seed coating layer is a key factor to determine the microstructure of NaA zeolite layer, secondary grown on a porous support.

Changing the Surface-Liquid Crystal Interaction through the Adsorption of Silica Nanoparticles

  • Finotello, Daniele;Jin, Tao
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.847-848
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    • 2004
  • We studied a low density 8CB liquid crystal-hydrophobic aerosil dispersions imbedded in submicron-size cylindrical pores. The nanosize spherical aerosil particles are adsorbed at the pore wall and hinder the planar anchoring. The adsorption is temperature dependent, and an axial to radial molecular configuration transition occurs within the cylindrical pores.

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