• Proceedings of the KSME Conference
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• 2001.11a
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• pp.716-722
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• 2001

In this paper, the modeling and control of electrostrictive polymer is introduced for endoscopic microcapsule. The endoscopic microcapsule works in the body, so the material of robot must be no harmful to the body. The electrostrictive polymer satisfies this condition. The modeling and control of endoscope microcapsule must be processed. So the modeling and control of electrostrictive was processed preferentially. The electrostrictive polymer is so flexible that we considered the electrostrictive polymer as flexible membrane. The dynamic equation of flexible membrane is time variant in electrostrictive polymer. It is the reason that the elastic modulus of electrostrictive polymer is very small and changes as deformation of electrostrictive polymer. The control algorithm must overcome these characteristics. So the algorithm of adaptive fuzzy control was used to control. In this paper, we introduced the dynamic modeling and control of electrostrictive polymer. And its deformation is introduced.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.321-323
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• 2005

We report a microcapsule-based electronic ink display technique, containing hollow titania particles which were prepared via a complex coacervation method using gelatin and gum arabic. In order to reduce density mismatch between nanoparticels and dielectric medium, hollow titania particles were introduced. Microcapsules were then prepared using gelatin to improve the elasticity of the microcapsule wall and their electrophoretic characteristics were $investigated^1$

• YAKHAK HOEJI
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• v.31 no.3
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• pp.182-188
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• 1987

Simple coacervation of bovine serum albumin was studied to prepare biodegradable microacapsule. Albumin microcapsules were prepared by using acrylonitrilestyrene polymer (M-80) resin beads and sulfamethoxydiazine as the core materials. The albumin to beads ratio was found to be 1:2.3 and the albumin to sulfamethoxydiazine ratio to be 1:2.9. The 50% release times (T$_{50%}$) of sulfamethoxydiazine and microencapsulated sulfamethoxydiazine were 6 min. and 73 min., respectively. The surface appearance of the microcapsule collected after release experiment was not different from those of the original microcapsule. In addition to slowing release of drug the microencapsulation process masked characteristic bitter taste of sulfamethoxydiazine.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.660-666
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• 2001

The Ionic Polymer Metal Composite (IPMC) is one of the electroactive polymer (EAP) have potential application as micro actuators. In this study, IPMC is used as actuator to control of the direction for the endscopic microcapsule. Because it bends in water and wet conditions by applying a low voltage $(1\sim3\;V)$ to its surfaces. The basic characteristics and the static modeling of IPMC are discussed. Also the dynamic modeling is performed using the Lagrange' equation. Computer simulation results show that the performed modeling guarantee similarity of actual system.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.4
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• pp.39-48
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• 2003

The Ionic Polymer Metal Composite (IPMC) is one of the electroactive polymer (EAP) have potential application as micro actuators. In this study, IPMC is used as actuator to control of the direction for the endscopic microcapsule. Because it bends in water and wet conditions by applying a low voltage (1∼3 V) to its surfaces. The basic characteristics and the static modeling of IPMC are discussed. Also the dynamic modeling is performed using the Lagrange' equation. Computer simulation results show that the performed modeling guarantee similarity of actual system.

• Elastomers and Composites
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• v.48 no.3
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• pp.232-240
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• 2013

Microcapsules having healing agent were prepared in which 2,6-dimethylphenol (DMP) as a healing agent forms the core and melamine/formaldehyde resin forms the shell. Microcapsule-contained asphalts showed better mechanical properties than non-contained ones. And as the rest time passed the impact strength of microcapsule-contained asphalt was getting higher than that of asphalt without the microcapsule. As the rest time of 15 days passed, the original strength was restored. This tells that microcapsule-contained asphalt had the ability of self-healing. X-ray photos proved that DMP on asphalt fracture surface, which were burst out of the microcapsules when cracks occurred on asphalt, were polymerized to polyphenyleneoxide and this PPO covered the crack and healed the damage.

• Applied Chemistry for Engineering
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• v.27 no.3
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• pp.270-275
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• 2016

High density polyethylene (HDPE)/kenaf fiber (KF) composites included two types of KF with different lengths were fabricated by using a twin screw extruder. A thermally expandable microcapsule (EMC) was used to form HDPE/KF. The KF lengths were 0.3 mm and 3 mm. The contents of KF and EMC were fixed at 20 wt% and 5 wt%, respectively. From FT-IR data of KF, which underwent chemical treatment, peaks around 1700 and $1300cm^{-1}$ decreased. This might be caused by the reduction of lignin and hemicellulose due to the chemical treatment of KF. Based on the specific gravity, thermal stability and tensile property, physical properties of the composites with a 3 mm fiber were good. However, if the fiber is longer, poor appearance might be caused due to the thermal degradation during processing. Thus, the adequate length of KF should be chosen to maintain the appearance and physical properties for industrial applications of HDPE/KF/EMC composites. The tensile strength for 0.3 mm fiber treated with chemicals increased slightly.

• Polymer(Korea)
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• v.26 no.3
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• pp.400-409
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• 2002

Polyurethane microcapsules containing functional oil (citronella oil) were successfully prepared by conventional interfacial polymerization of tolulene 2,4-diisocyanate (TDI) and ethylene glycol (EG) and characterized by Fourier transform (FT-IR) spectroscopy, Ultraviolet spectroscopy, particle size analysis, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). Tile effects of polymerization variables, such as surfactant concentration and agitation speed, on the particle size and particle size distribution were investigated. FT-IR spectroscopic data showed that citronella oil was successfully encapsulated in the microcapsule. Thermogravimetric analysis data showed that the microcapsule was thermally stable up to $220^{\circ}C$. The controlled release of the citronella oil present in the microcapsule core in a methanol medium was demonstrated by ultraviolet spectroscopy showing that the amount of released citronella oil was increased with increasing time. It was observed that the amount of released citronella oil was increased with increasing stirring speed and emulsifier concentration in the rnicrocapsule preparation step. Polyurethane microcapsules containing citronella oil showed excellent anti-moth property.

• Polymer(Korea)
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• v.36 no.6
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• pp.768-775
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• 2012

Alginate, obtained from the seaweeds, is a widely used biomaterial for cell transplantation, since its positive effect on viability of capsulized cells and its easier encapsulation capability of living cells. Demineralized bone powder (DBP), derived from the natural bone tissue, is widely applied for clinical trials for its low rate of reaction and antigenicity. A chondrocyte was seeded into an alginate with DBP of different contents, and a microcapsule was produced. The adhesion and proliferation of cells was observed through the MTT analysis, and the PCR was applied to estimate the content of the glycosaminoglycan (sGAG) and collagen, and confirm the specific genetic pattern of the chondrocytes. Also, the alginate microcapsule where the chondrocyte is seeded was extracted after transplantation under the skin of a nude mouse, and was immunochemically stained. The experimental result confirmed that the alginate microcapsule containing 1% of DBP not only showed the highest proliferation of cell but had a positive effect of chondrocytes by the interaction between the alginates and the growth factor in DBP. It can be expected that the microcapsule with application of the alginates and DBP might be an appropriate scaffold for tissue engineering.

• Polymer Science and Technology
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• v.25 no.2
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• pp.121-127
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• 2014