• Title/Summary/Keyword: Nano particle

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Functional Properties of Milk Protein in Fermented Milk Products (발효유제품의 유단백질 기능성 연구 동향)

  • Lee, Won-Jae
    • Journal of Dairy Science and Biotechnology
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    • v.25 no.2
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    • pp.29-32
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    • 2007
  • An understanding functional properties and molecular interactions of milk proteins was critical to improve qualities of fermented dairy products including yogurts and cheeses. Extensive rearrangements of casein particles were important factors to enhance whey separation in yogurt gel network. The use of high hydrostatic pressure treated whey protein as an ingredient of low fat processed cheese food resulted in the production of low fat processed cheese food with acceptable firmness and enhanced meltabilities. Milk protein-based nano particles produced by self-association of proteins could be better nutrient delivery vehicle than micro particle since particle size reduction in nano particles could lead to increased residence time and surface area available in GI tract.

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Development and Applications of Frame Retardant Nano and Microcapsule (난연기능 nano 및 microcapsule의 개발 및 응용(Ⅰ))

  • Kim, Hea-In;Hong, Yo-Han;Park, Soo-Min
    • Textile Coloration and Finishing
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    • v.20 no.4
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    • pp.31-42
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    • 2008
  • Tricrecyl phosphate(TCP)-containing polyurea microcapsules were prepared by interfacial polymerization using aromatic 2,4-toluene diisocyanate(TDI) and ethylenediamine(EDA) as wall forming materials. The effects of the protective colloids of polyvinylalcohol(PVA) and gelatin were investigated through experimentation. The mean size of prepared polyurea microcapsules was smaller and the surface morphology of the microcapsule prepared by the PVA as protective colloid was much smoother than the gelatin. As the concentration of protective colloid increased, the wall membrane of the polyurea microcapsules became more stable, the thermal stability of the wall membrane increased, the mean particle size became smaller, and the particle distribution was more uniform. PET containg microTCPs have a higher activation energy of decomposition, higher char content and lower heat of combustion.

Functional Properties of Milk Protein in Fermented Milk Products (발효 유제품에서의 유단백질 기능성 연구 동향)

  • Lee, Won-Jae
    • 한국유가공학회:학술대회논문집
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    • 2007.09a
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    • pp.31-37
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    • 2007
  • An understanding functional properties and molecular interactions of milk proteins was critical to improve qualities of fermented dairy products including yogurts and cheeses. Extensive rearrangements of casein particles were important factors to enhance whey separation in yogurt gel network. The use of high hydrostatic pressure treated whey protein as an ingredient of low fat processed cheese food resulted in the production of low fat processed cheese food with acceptable firmness and enhanced meltabilities. Milk protein-based nano particles produced by self-association of proteins could be better nutrient delivery vehicle than micro particle since particle size reduction in nano particles could lead to increased residence time and surface area available in GI tract.

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Improving Wrinkle Resistance of Cotton Fabric by Montmorillonite

  • Yuen C.W.M.;Kan C.W.;Lee H.L.
    • Fibers and Polymers
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    • v.7 no.2
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    • pp.139-145
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    • 2006
  • Cotton fabric was treated with montmorillonite (MMT) so as to evaluate its effectiveness on improving its wrinkle resistance. The MMT in emulsion form was applied to cotton fabric by padding and finally the wrinkle resistance of the MMT-treated cotton fabric was improved. Furthermore, instrumental methods were used for studying the presence of MMT particles on the cotton fabric surface. It was noted that nano-scale MMT particles adhered on the fiber surface and the particle size played an important role in influencing the wrinkle resistance of the cotton fabric. The experimental results are discussed thoroughly in this paper.

Effects of Composition and Additives on the Mechanical Characteristics of 3Y-TZP (3Y-TZP의 기계적 특성에 미치는 산화물 조성 및 첨가제의 영향)

  • Park, Mi-Jung;Yang, Seong-Koo;Kang, Jong-Bong
    • Journal of the Korean Ceramic Society
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    • v.43 no.10 s.293
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    • pp.640-645
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    • 2006
  • Monoclinic zirconia and yttria were mixed with a stoichiometric composition of 3Y-TZP (3 mol% Yttria-stabilized Tetragonal Zirconia Polycrystal). The specimen was sintered at 1350$\sim$1450$^{\circ}C$ and mechanical characterization and microstructure analysis were conducted. Microhardness and fracture toughness were shown as 1357.4 Hv and 8.56 MPa $m^{1/2}$. respectively. Without alumina, they were 1311 Hv and 10.02 MPa $m^{1/2}$ respectively. By mixing two different oxides, it was possible to obtain high values of microhardness and fracture toughness. It was possible that was turned out nano-scale particle using the co-milling of high mechanical energy.

Nano-level Device 제조를 위한 신 메탈 전극 세정에 관한 연구

  • 변재호;송용화;천희곤
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2003.12a
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    • pp.64-67
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    • 2003
  • 본 연구는 nano-level 디바이스 제조를 위한 새로운 금속 전극인 W 과 Ti metal 표면 세정에 관한 연구이다. 기존 $SC-1(NH_4OH/H_2O_2/H_2O)$ 세정 용액에서 산화제 ($H_2O_2$)를 사용하지 않는 dilute $NH_4$OH 세정은 전극 사이 절연막 표면의 particle 제거가 가능하면서 노출된 metal 막의 세정 damage를 최소화 시키는 것을 확인했다. SC-1 용액 내에 산화제 미 첨가 효과는, metal 막의 식각 현상을 억제시키고, 절연막 표면의 particle 제거 효과에 영향을 미치지 않는 것으로 판단된다. 이러한 방법은 short time 공정이 필요한 관계로, spin type wet 장비 채택으로 세정 효과의 극대화를 얻을 수 있을 것으로 판단된다.

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Magnetic Behaviors of Isolated Fe-Co-Ni Nanoparticles in a Random Arrangement

  • Yang, Choong Jin;Kim, Kyung Soo;Wu, Jianmin
    • Journal of Magnetics
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    • v.6 no.3
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    • pp.94-100
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    • 2001
  • Fe-Co-Ni particles with an average size of 45 and 135 nm are characterized in terms of magnetic phase transformation and magnetic properties at room temperature. BCC structure of Fe-Co-Ni spherical particles can be synthesized from Fe-Co-Ni-Al-Cu precursor films by heating at 600-80$0^{\circ}C$ for the phase separation of Fe-Co rich Fe-Co-Ni particles, followed by a post heating at $600^{\circ}C$ for 5 hours. The average size of nanoparticles was directly determined by the thickness of precursor films. Exchange interactive hysteresis was observed for the nano-composite (Fe-Co-Ni)+(Fe-Ni-Al) films resulting from the short exchange interface between ferromagnetic Fe-Co-Ni particles surrounded by almost papramagnetic Ni-Al-Fe matrix. Arraying the isolated Fe-Co-Ni nano-particles in a random arrangement on $Al_2O_3$substrate the particle assembly showed a behavior of dipole interactive ferromagnetic clusters depending on their volume and inter-particle distance.

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Synthesis of Nano Metal Powder by Electrochemical Reduction of Iron Oxides

  • Seong, Ki-Hun;Lee, Jai-Sung
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09a
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    • pp.482-483
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    • 2006
  • Synthesis of iron nanopowder by room-temperature electrochemical reduction process of ${\alpha}-Fe_2O_3$ nanopowder was investigated in terms of phase evolution and microstructure. As process variables, reduction time and applied voltage were changed in the range of $1{\sim}20$ h and $30{\sim}40$ V, respectively. From XRD analyses, it was found that volume of Fe phase increased with increasing reduction time and applied voltage, respectively. The crystallite size of Fe phase in all powder samples was less than 30 nm, implying that particle growth was inhibited by the reaction at room temperature. Based on the distinct equilibrium shape of crystalline particle, phase composition of nanoparticles was identified by TEM observation.

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Thermal Degradation Analyses of Epoxy-Silica Nano Composites (에폭시-실리카 나노 복합소재의 열화 특성 및 거동 분석)

  • Jang, Seo-Hyun;Han, Yusu;Hwang, Do Soon;Jung, Joo Won;Kim, Yeong K.
    • Composites Research
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    • v.33 no.5
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    • pp.268-274
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    • 2020
  • This paper analyzed the degradation behaviors of silica nano epoxy composite based on the isoconversional method. The size of the silica nano particle was about 12 nm and the particles were mixed by three different weight ratios to make the degradation test samples. The thermogravimetric analyses were performed under six different temperature increase rates to measure the weight changes. Four different methods, Friedman, Flynn-Wall-Ozawa, Kissinger and DAEM (Distributed Activation Energy Method), were employed to calculate the activation energies depending on the conversion ratios, and their calculation results were compared. The results represented that the activation energy was increased when the silica nano particles were mixed up to 10%, indicating the definite contribution of the particles to the degradation behavior enhancements. However, the enhancement was not proportional to the particle mixture ratio by demonstrating the similar activation energies between 10% and 18% samples. The calculation results by the different methods were also compared and discussed.

Synthesis of Pt@TiO2 Nano-composite via Photochemical Reduction Method (광화학 환원방법을 이용한 Pt@TiO2 나노 복합체 합성)

  • Kim, Ji Young;Byun, Jong Min;Kim, Jin Woo;Kim, Young Do
    • Journal of Powder Materials
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    • v.21 no.2
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    • pp.119-123
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    • 2014
  • Pt has been widely used as catalyst for fuel cell and exhausted gas clean systems due to its high catalytic activity. Recently, there have been researches on fabricating composite materials of Pt as a method of reducing the amount of Pt due to its high price. One of the approaches for saving Pt used as catalyst is a core shell structure consisting of Pt layer on the core of the non-noble metal. In this study, the synthesis of Pt shell was conducted on the surface of $TiO_2$ particle, a non-noble material, by applying ultraviolet (UV) irradiation. Anatase $TiO_2$ particles with the average size of 20~30 nm were immersed in the ethanol dissolved with Pt precursor of $H_2PtCl_6{\cdot}6H_2O$ and exposed to UV irradiation with the wavelength of 365 nm. It was confirmed that Pt nano-particles were formed on the surface of $TiO_2$ particles by photochemical reduction of Pt ion from the solution. The morphology of the synthesized Pt@$TiO_2$ nano-composite was examined by TEM (Transmission Electron Microscopy).