• Title/Summary/Keyword: Monodisperse

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Carbon-Silica Membrane for Gas Separation (탄소-실리카막을 이용한 기체분리)

  • Lee, Young-Moo;Park, Ho-Bum
    • Proceedings of the Membrane Society of Korea Conference
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    • 2004.03a
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    • pp.77-102
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    • 2004
  • Carbon materials obtained from organic polymers are usually amorphous structure. The structure of carbon materials is not nearly as well defined as that of zeolite. Carbon are amorphous materials with comparatively wide pore size distribution as compared to the crystalline zeolites with monodisperse ultramicropore and micropore dimensions. (omitted)

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Analytic Solutions to Diffusional Deposition of Polydisperse Aerosols in Fibrous Filters (섬유질 필터내의 다분산 에어로졸 입자의 확산 침착에 관한 해석적 해)

  • Gwon Sun-Park;Kim Hyeon-Tae;Lee Gyu-Won
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2001.11a
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    • pp.389-390
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    • 2001
  • Deposition of polydisperse aerosols by Brownian diffusion was studied analytically using the penetration efficiency of monodisperse aerosols combined with the correlations among the moments of lognormal distribution functions. The analytic solutions so obtained were validated using the exact solution were applied to recalculate the filtration efficiencies of the existing experimental data for various filtration conditions. (omitted)

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Response of laser light active scattering aerosol spectrometer to light-absorbing aerosol particulates (광흡수성 분체입자에 대한 레이저산란광 분체입도측정기의 반응 특성)

  • Jeung, I. S.
    • Journal of the korean Society of Automotive Engineers
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    • v.6 no.2
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    • pp.55-63
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    • 1984
  • Berglund-Liu 진동방식 단분산 분체입자 발생기(Berglund-Liu vibrating orifice monodisperse aerosol generator)에 의하여 제작한 단분산 광흡수성 표준분체입자를 사용하여 레이저 산란광 분체입도 측정기 (Knollenberg active scattering aerosol spectrometer)의 반응특성을 조사하 였다. 실험결과, 기기의 반응특성은 Mie 산란이론에 의하여 계산한 이론치와 매우 잘 일치하며 특히 광흡수성 분체입자는 광통과성 분체입자가 다의적인 특성을 나타내는 것에 반하여 거의 단조증가하는 일의적인 특성을 가지고 있으며 광흡수성 분체입자의 반응특성이 제작자의 교정 치에 가까운 결과를 나타내었다.

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Preparation of Monodisperse Submicron-Sized Polymeric Particles by Emulsifier-Free Emulsion Polymerization (무유화중합에 의한 단분산 Submicron 크기의 고분자 미립자의 제조)

  • Lee, Ki-Chang
    • Journal of Adhesion and Interface
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    • v.13 no.3
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    • pp.101-108
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    • 2012
  • Narrowly dispersed poly(BMA-co-MMA) and PBMA latices (PSD : 1.002~1.008) were synthesized successfully by surfactant-free emulsion polymerization with 2,2' azobis(2-methyl-propionamidine) dihydrochloride (AIBA) and $K_2S_2O_8$ (KPS). The number average particle diameter and the number average molecule weight were found to be 160~494 nm and (1.25~7.55) ${\times}10^4$, respectively. The influences of BMA/MMA ratio, monomer and initiator concentrations, addition of DVB/EGDMA crosslink agent, and polymerization temperature on the polymerization rates and on the particle size and molecular weight were studied. The rate of polymerization increased with increasing MMA concentration in BMA/MMA weight ratio. The particle diameter as well as the polymer molecular weight could be controlled easily by controlling the BMA/MMA weight ratio, monomer concentration, AIBA and KPS concentration, and polymerization temperature.

Preparation of Monodisperse Blue-colored Polymeric Particles with High Zeta-potential (높은 제타전위를 갖는 단분산의 블루착색 고분자미립자의 제조)

  • Lee, Ki-Chang;Nam, Sang-Yong
    • Journal of Adhesion and Interface
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    • v.13 no.3
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    • pp.109-115
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    • 2012
  • Monodisperse blue-colored poly(styrene-co-acrylic acid) latices were successfully prepared by seeded emulsion polymerization. Blue-colored latices with carboxyl anionic charge on the surface were synthesized at the second stage with the introduction of Blue 606 dye, acrylic acid, and 0.21 ${\mu}m$-polystyrene seed. All the blue-colored latices synthesized in this study were in the size range of 0.25~0.42 ${\mu}m$ and all uniform with less than 1.01 in PSD. The particle size increased with the addition of acrylic acid being delayed and colloidally stable latices were obtained over 30 min after its addition. The blue-colored latex with 20 wt% acrylic acid showed -145 mV of zeta-potential and $-9.4{\times}10^{-6}\;cm^2/Vs$ of electrophoretic mobility, and with 25 wt% of DVB showed high $T_g$ at 396.7 K.

Microfluidic Preparation of Monodisperse Multiple Emulsion using Hydrodynamic Control (미세채널에서 수력학적 조절을 통한 단분산성 다중 액적 생성)

  • Kang, Sung-Min;Choi, Chang-Hyung;Hwang, Sora;Jung, Jae-Min;Lee, Chang-Soo
    • Korean Chemical Engineering Research
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    • v.50 no.4
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    • pp.733-737
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    • 2012
  • This study reports the microfluidic preparation of monodisperse multiple emulsions using hydrodynamic control. To generate multiple emulsions, we fabricate a microfluidic capillary device based on co-flowing stream without any surface modification of microchannels. Based on the system, we can successfully generate multiple emulsions (W/O/W) using water containing 0.5 wt% Tween 20, n-hexadecane with 5 wt% Span 80, and 10 wt% poly (vinyl alcohol) (PVA) aqueous solution, respectively. Furthermore, we control the number of inner droplets by modulation of flow rate of inner fluid at fixed flow rate of middle and outer fluid. The multiple emulsions having precisely controlled inner droplets' size and number can be applicable for multiple chemical reactions as an isolated microreactor.