• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.8
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• pp.518-523
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• 2015

We fabricate a single particle-microcapsule type electronic paper using electrophoresis, which is different with a reported dual particle-microcapsule type and of which electro-optical researches are not reported. So we analyzed a basic properties, such as reflectivity, response time, and driving voltage. Our display panels having various cell-gaps of $30{\mu}m$, $34{\mu}m$, $38{\mu}m$, $42{\mu}m$, and $46{\mu}m$ are inspected. As a results, a driving voltage is defined to 10 V and desirable cell-gap is $30{\mu}m$ or $34{\mu}m$. Considering a mechanical strength, the optimum cell-gap is $34{\mu}m$ for the single particle type electronic paper.

• Toxicological Research
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• v.23 no.1
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• pp.87-96
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• 2007

Single and repeated-dose toxicity of anti-diabetic herb extract microcapsule (ADHEM) were evaluated according to Toxicity Test Guidelines of Korea Food and Drug Administration using Sprague-Dawley rats. For single-dose toxicity test, kneading ADHEM with sterilized water were administered orally once at dose levels of 0 and 2,000 mg/kg and examined for 14 days. No dead animals, clinical signs and abnormal necropsy findings were observed and also no significant difference in body weights was found. Therefore, the $LD_{50}$ of ADHEM was considered to be higher than 2,000 mg/kg in both male and female rats. For repeated-dose toxicity test, ADHEM were mixed with powder fodder and administerd orally for 28 days at dose levels of 0, 500, 1000 and 2000 mg/kg/day. No dead animals, clinical signs and significant difference in body weights were found. In hematology and serum biochemistry, all values were included within the normal ranges. In relative organ weights, kidney or liver were significantly increased in the 500, 1000 or 2000 mg/kg/day male groups, uterus was significantly increased in the 500 mg/kg/day female group and left adrenal glands were significantly decreased in the 2000 mg/kg/day female group. In histopathological examinations, vacuolation and microgranuloma in the liver, chronic progressive nephropathy and inflammation in the kidney were observed in the 500, 1000 or 2000 mg/kg/day both male and female groups. Therefore, the no observed adverse effect level (NOAEL) of ADHEM was considered to be lower than 500 mg/kg/day in both male and female rats.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.509-511
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• 2003

We present a microcapsule manufacturing technique, which contains a polymer coated white $TiO_2$ and black particles suspension as the core material for a electrophoretic display ink, via the in-situ polymerization method using melamine? formaldehyde as a wall material. The obtained capsules have $50 {\sim} 300 {\mu}m$ of the diameter range. They show a good mechanical strength and thermal and optical property. We fabricate the microcapsules to the single layer to test the black/white electrophoretic display application.

• Korean Chemical Engineering Research
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• v.51 no.5
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• pp.597-601
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• 2013

In this study, we present simple microfluidic approach for the synthesis of monodisperse microcapsules by using droplet-based system. We generate double emulsion through single step in the microfluidic device having single junction while conventional approaches are limited in surface treatment for the generation of double emulsion. First, we have injected disperse fluid containing FC-77 oil and photocurable ethoxylated trimethylolpropane triacrylate (ETPTA) and water containing 3 wt% poly(vinyl alcohol) (PVA) as continuous phase into microfluidic device. Under the condition, we easily generate double emulsion with high monodispersity by using flow focusing. The double emulsion droplets are transformed into microcapsules under the UV irradiation via photopolymerization. In addition, we control thickness of double emulsion's shell by controlling flow rate of ETPTA. We also show that the size of double emulsions can be controlled by manipulation of flow rate of continuous phase. Furthermore, we synthesize microcapsules encapsulating various materials for the application of drug delivery systems.

• Membrane Journal
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• v.27 no.6
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• pp.511-518
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• 2017

The membrane emulsification (ME) is a technology for producing emulsions with narrow size distribution by using the well-defined porous membranes such as the SPG membrane. In this study, the preparation of polycaprolactone (PCL) microcapsules by using the multiple emulsions obtained from membrane emulsification method is studied. After the making of $W_1/O$ single emulsions by sonication method, then $W_1/O/W_2$ multiple emulsions are formed by premix-ME method. The PCL microcapsules impregnated with BSA model drug are prepared by solvent evaporating from $W_1/O/W_2$ multiple emulsions. The effects of various parameters such as the ratio of disperse/continuous phase (D/C ratio), the concentration of PCL, emulsifier and model drug and the transmembrane pressure on the size and distribution of PCL microcapsules are investigated. The uniform PCL microcapsules with about $5{\sim}6{\mu}m$ of mean size and 26% of BSA loading are obtained by the premix membrane emulsification.