• Textile Coloration and Finishing
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• v.17 no.3 s.82
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• pp.26-33
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• 2005

EVA microsphere was prepared by a thermally induced phase separation. EVAL microsphere was made by a saponification on sheath of EVA microsphere. And microcapsule with EVA core-PU shell structure was synthesized by interfacial polymerization using diisocyanates with PEG in gelatin aqueous solution as the stabilizing agent. The effects of chemical structure of diisocyanate on the average particle size and distribution, morphology, color strength and friction fastness of core-shell particles were investigated to design microcapsule. The friction fastness of the fabrics printed with EVA core-PU shell microcapsules had the 4-5 grade.

• 한국가시화정보학회:학술대회논문집
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• 2005.12a
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• pp.89-92
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• 2005

A microcapsule for drug delivery was successfully produced by utilizing the flow-through droplet-based supramolecular self-assembly in a crossed microchannel network. The PS-b-PMMA block copolymer synthesized atom transfer radical polymerization (ATRP) was initially formed as microdroplets and after the evaporation process it turned to spherical capsule by polymer self-assembly of the micro domains. The characteristics were studied using various analysis methods.

• Textile Coloration and Finishing
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• v.9 no.5
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• pp.63-74
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• 1997

Polyurethane microcapsules were synthesized by interfacial polymerization in an aqueous poly(ethylene glycol) dispersion with ethylenediamine as chain extender of toluene diisocyanate in perfume oil using poly(vinyl alcohol) as the stabilizing agent. The effect of chemical structure on the average particle size and distributions, morphologies, and thermal properties to design microcapsules for the sustained release system was investigated. It came to be known that polyurethane microcapsules with ethylene diamine as chain extender had a rounder, more permeable and controlled release membranes. And the release test of polyurethane microcapsules with different soft segment content was done to certify the effect of long methylene chain. According to the higher molecular weight of polyether polyol, the release rate of microencapsulated disperse dye molecular was faster.

• Textile Coloration and Finishing
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• v.9 no.5
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• pp.52-62
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• 1997

Abstract Polyurethanes have been designed and fabricated into membranes with unique separation properties. Moreover, polyurethane microcapsules also have been reported actively as controlled release materials for their excellent blood compatibility, tensile strength and permeability. In this study, polyurethane microcapsules were synthesized by interfacial polymerization in an aqueous poly(ethylene glycol) dispersion of toluene diisocyanate in perfume oil using poly(vinyl alcohol) as the stabilizing agent. The effect of a few important process conditions on the average particle size and distributions, morphologies, and thermal properties to design microcapsules for the sustained release system was investigated.

• Polymer(Korea)
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• v.33 no.4
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• pp.347-352
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• 2009

Charged organic-inorganic composite particles were prepared for the application to electrophoretic display technology such as electronic paper. $TiO_2$ and $Co_3O_4$ particles were used for core particles and were coated with poly(methyl methacrylate) by dispersion polymerization. Composite particles were endowed with charge moiety for electrophoresis; positive charge for $TiO_2$ and negative charge for $Co_3O_4$ composite particles. Scanning electron microscopic results revealed that the charged composite particles have spherical shape. Densities of the composite particles were controlled to be that of medium of electrophoresis. Density of $TiO_2$ particle changed from 4.02 to 1.44 g/$cm^3$ after the polymer coating, and that of $Co_3O_4$ particles changed from 6.11 to 1.49 g/$cm^3$. Urea, melamine, and formaldehyde were used as wall materials for capsule, and microcapsule containing black or white particles inside were prepared by in-situ polymerization. Microcapsule showed the inspection by a video microscope demonstrated the formation of uniform transparent capsules.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.147-153
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• 2018

PLGA microcapsule particles encapsulating BSA aqueous solutions were prepared using a water-in-oil-in-water emulsion method. The morphology, particle size, BSA encapsulating efficiency, and in-vitro release test were also studied using the microcapsule particles. In the outer aqueous phase, an emulsifier, e.g., PVA, was replaced with metal salts for surface solidification. Scanning electron microscopy (SEM) showed that the microcapsule particles had smooth surfaces and were between $1{\mu}m$ and $7{\mu}m$ in size. The microcapsule particle morphology was affected directly by the ratio between the polymer solution and inner aqueous solution, and composition of the outer aqueous solution. The factors also partially affected the BSA encapsulation efficiencies and in-vitro release rates. All the microcapsule particles showed an initial burst release through the in-vitro release test. On the other hand, the particles also showed a relatively long release period. Metal salts could be good choices to replace the emulsifier to solidify the microcapsule particle surfaces.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.93-96
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• 2001

Structural polymer composites are susceptible to damage in the form of cracks, which form deep within the structure where detection is difficult and repair is almost impossible. A recent methodology for the damage repair of polymer composites using the self-healing technique is reported. The polymerization of the healing agent is triggered by contact with an embedded catalyst, being necessary to damage repair of polymer composites. For this purpose, the self-healing concept is introduced and the manufacturing process of microcapsule with the healing agent is briefly described. The polymerization between the healing agent and the catalyst is verified by the use of ESEM and IR spectroscopy. Finally the efficiency of the self-healing technique is investigated by measuring the critical load of TDCB specimen.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.177-186
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• 1994

Bioadhesive microcapsules of cephalexin, using Eudragit RS/RL coated with polycarbophil or carbopol, were evaluated biopharmaceutically. The GI transit of microcapsules in rats was studied. Bioadhesive microcapsules coated with polycarbophil or carbopol were shown to have substantially longer GI transit time than Eudragit RS/RL microcapsule. The delay in transit time was due to bioadhesion of the polymer to the mucin-epithelial cell surface which was clearly observable on animal autopsy. Plasma drug levels in rabbits showed that bioadhesive microcapsules resulted in a longer duration of action and greater bioavailability than other microcapsule or drug powder. Thus, the principle of bioadhesion can significantly improve therapy, due to a reduced rate of gastric emptying, an increase in contact time, and the intimacy of contact of the drug with the absorbing membrane.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.3025-3032
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• 2012

Carbon microcapsules containing silicon nanoparticles (Si NPs)-carbon nanotubes (CNTs) nanocomposite (Si-CNT@C) have been fabricated by a two step polymerization method. Silicon nanoparticles-carbon nanotubes (Si-CNT) nanohybrids were prepared with a wet-type beadsmill method. A polymer, which is easily removable by a thermal treatment (intermediate polymer) was polymerized on the outer surfaces of Si-CNT nanocomposites. Subsequently, another polymer, which can be carbonized by thermal heating (carbon precursor polymer) was incorporated onto the surfaces of pre-existing polymer layer. In this way, polymer precursor spheres containing Si-CNT nanohybrids were produced using a two step polymerization. The intermediate polymer must disappear during carbonization resulting in the formation of an internal free space. The carbon precursor polymer should transform to carbon shell to encapsulate remaining Si-CNT nanocomposites. Therefore, hollow carbon microcapsules containing Si-CNT nanocomposites could be obtained (Si-CNT@C). The successful fabrication was confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). These final materials were employed for anode performance improvement in lithium ion battery. The cyclic performances of these Si-CNT@C microcapsules were measured with a lithium battery half cell tests.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.344-344
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• 2006

Poly(n-hexyl-(S)-3-methylpentylsilane) aggregates confined in microcapsules to keep the aggregation number and ranging in average polymer mass in a microcapsule from $2{\Box}10^{-16}\;to\;2{\Box}10^{-14}g$. were studied by circular dichroism measurements in ethanol (a non solvent) and tetrahydrofuran (an associative solvent at low temperature) at varioustemperatures. The size of each aggregate did not affect the optical activity because the circular dichroism was proportional to the aggregation number at the same condition. Moreover, the circular dichroism appreciably reflected the prepared method, i.e. temperature and solvent.