• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.197-198
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• 2009

고분자 전해질막으로 사용할 수 있는 소수성/친수성 랜덤 멀티블럭 공중합체를 합성하였다. 공중합체는 수산화기를 각 말단에 가지고 있는 소수성 올리고머, 친수성 올리고머 및 반응성이 좋은 커플링 단량체로 친핵성 치환 반응을 활용하여 합성 하였다. 높은 반응성의 커플링 단량체의 존재로 비교적 낮은 온도에서 합성이 됨으로서 고온에서의 에테르-에테르 교환반응에 의한 랜덤화를 억제할 수 있었으며, 높은 중합도의 공중합체를 합성 할 수 있었다. 각 수산화기로 같은 말단으로 조정된 올리고머는 투입 비율의 조정으로 쉽게 이온교환용량을 조정할 수 있었다. 솔루션 캐스팅 방법으로 강도를 가지고 잘 휘어지며 투명한 전해질막을 제조할 수 있었다. 전해질막은 이온전도도, 물흡수율, 부피 변화율, 연료 투과성 등의 측정이 되었다.

• Elastomers and Composites
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• v.34 no.1
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• pp.45-52
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• 1999

This paper describes how the gold particles self assemble on the specific phase on the microphase separated block copolymer thin film and form a well ordered patterns. For this study, polystyrene-polybutadiene-polystyrene (PS-PB-PS) triblock copolymer (30wt % PS) thin films (${\sim}100nm$) having a cylindrical morphology were cast from 0.1wt% toluene solution to be used as polymer thin film templates. The films having either vertical PS cylinders or in-plane PS cylinders in PB matrix from each different solvent evaporation condition were obtained. Cross-sectional transmission electron microscopy(TEM) was used to study the surface and bulk morphologies of block copolymer thin films. Small amount of gold particles was evaporated on a block copolymer thin film template to obtain a nano-scale pattern. When an as-cast thin film template was used, gold particles preferentially self assemble on the low surface tension PB phase and a relatively well ordered pattern in nano-scale was produced. However, after the formation of a low surface energy PB rich layer upon annealing, a gold self-assembled pattern was not observed.

• Polymer(Korea)
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• v.24 no.5
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• pp.664-672
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• 2000

It is generally agreed that transesterification provides the, copolymer in the melt blending of poly(ethylene naphthalate) (PEN) and poly($\varepsilon$-caprolactone) (PCL). Effects of the conditions of transesterification reaction and catalyst on the degree of randomness and average sequence length of PEN/PCL blends were investigated and results were used to interpret the biodegradability of PEN/PCL blends. It was found that degree of randomness values of obtained copolymer lied between 0 and 1, and it indicated that this blend consisted with physical blends of PEN/PCL and PEN/PCL block copolymers. The degree of randomness reached almost 1 which is the theoretical value of random copolymers and the average sequence length became shorter by the further transesterification reaction. In additions, it was found that the increase of copolymers, especially random copolymers reduced the biodegradability in PEN/PCL blends.

• Proceedings of the Korean Fiber Society Conference
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• 2001.04a
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• pp.135.2-139
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• 2001

• Applied Chemistry for Engineering
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• v.5 no.5
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• pp.851-856
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• 1994

Compatibility and viscoelasticity in non-solvent type pressure sensitive adhesive of styrene-isoprene-styreno(SIS) block copolymer with tackifier resin were investigated. In the isoprene phase of SIS block copolymer, it was found that it's compatibility with $C^5$ petroleum resin was good, but that with Coumarone-indents resin was not so good. The magnitudes of peel strength, tack, and holding power were as follows : $C^5$ petroleum resin>rosin ester resin>coumarone-indene resin. The tackifier resin with good compatibility in rubber phase was also effective. However, with plateau modulus value of $1{\times}10^6-3{\times}10^6dyn/cm^2$, the effect of pressure sensitive adhesives was excellent.

• Analytical Science and Technology
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• v.27 no.5
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• pp.228-233
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• 2014

Electrospun polymeric nanofibers have been extensively studied for biomedical materials because of their unique structures and relatively easy fabrication with biocompatible polymers. The amount of surface exposed amine groups increases as the blend ratio of block copolymer increases. Cell attachments on the nanofibers change according to the ratio of the block copolymer ((Poly(e-caprolactone, PCL), Poly(e-caprolactone)-Poly (ethylen glycol-$NH_2$)) in the blend. We assume that the PEG and amine moiety plays a significant role in biocompatibility of nanofiber surfaces. Collagen was used as a grafting material on the composite nanofibers to enhance the cell adhesion because the collagen is a major constituent of connective tissue.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.6
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• pp.660-669
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• 2016

A fluorinated-sulfonated, hydrophobic-hydrophilic copolymer was planed subsequently synthesized using typical nucleophilic substitution polycondensation reaction. A novel AB and ABA (or BAB) block copolymers were synthesized using sBCPSBP (sulfonated 4,4'-bis[4-chlorophenyl)sulfonyl]-1,1'-biphenyl), DHN (1,5-dihydroxynaphthalene), DFBP (decafluorobiphenyl) and HFIP (4,4'-hexafluoroisopropylidenediphenol). All block copolymers were easily cast and made into clear films. The structure and synthesized copolymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (Fourier transform infrared). TGA (Thermogravimetric analysis) and DSC (differential scanning calorimetry) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. Hydrophobic/hydrophilic phase separation and clear ionic aggregate block morpology was confirmed in both triblock and diblock copolymer in AFM (atomic force microscopy), which may be highly related to their proton transport ability. A sulfonated BAB triblock copolymer membrane with an ion-exchange capacity (IEC) of 0.6 meq/g has a maximum ion conductivity of 40.3 mS/cm at $90^{\circ}C$ and 100% relative humidity.

• Proceedings of the Korean Fiber Society Conference
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• 2002.04a
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• pp.352-354
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• 2002

A series of ABA type triblock copolymers of trimethylene carbonate (TMC) and $\varepsilon$-caprolactone($\varepsilon$-CL) with different molar ratio were synthesized using ethylene glycol as initiator and stannous octoate as catalyst by ring-opening bulk polymerization. The characterization of the triblock copolymers was characterized by $^1$H-NMR, $\^$13/C-NMR, FT-IR, GPC and DSC, and compared with random copolymer. (omitted)

• Journal of Adhesion and Interface
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• v.14 no.2
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• pp.82-87
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• 2013

Preliminary studies on the synthesis of magnetic nanoparticles including nanoporous carbon materials have been done via a direct carbonization process from resol, ferric nitrate and triblock copolymer F127. The results show that the nanoporous magnetite/carbon ($Fe_3O_4$/carbon) with a low $Fe_3O_4$ content (1 wt%) possesses an ordered 2-D hexagonal (p6mm) structure, uniform nanopores (3.6 nm), high surface areas (up to 635 $m^2/g$) and pore volumes (up to 0.48 $cm^3/g$). Magnetite nanoparticles with a small particle size (10.2 nm) were confined in the matrix of amorphous carbon frameworks with superparamagnetic property (7.7 emu/g). The nanoporous magnetite/carbon showed maximum adsorption amount (995 mg/g) of ibuprofen after 24 h at room temperature. The nanoporous magnetite/carbon was separated from solution easily by using a magnet. The nanoporous magnetite/carbon material is a good adsorbent for hydrophobic organic drug molecules, i.e. ibuprofen.

• Journal of Adhesion and Interface
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• v.17 no.4
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• pp.141-148
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• 2016

In this work, mesoporous silica (SBA-15) was synthesized via self-assembly process using triblock copolymer ($PEO_{20}PPO_{70}PEO_{20}$, P123) as template and tetraethyl orthosilicate (TEOS) as silica source under acidic condition. SBA-15 have high surface area ($704m^2g^{-1}$) and uniform pore size (8.4 nm) with well-ordered hexagonal mesostructure. Spiropyran-functionalized SBA-15 (Spiropyran-SBA-15) was synthesized via post-synthesis process using 3-(triethoxysilyl)propyl isocyanate (TESPI) and 1-(2-Hydroxyethyl)-3,3-dimethy-lindolino-6'-nitrobenzopyrylo-spiran (HDINS). Spiropyran-SBA-15 was produced with hexagonal array of mesopores without damage of mesostructre. Surface area and pore size of Spiropyran-SBA-15 were $651m^2g^{-1}$ and 8.0 nm, respectively. Optochemical properties of Spiropyran-SBA-15 was studied with chemical vapors such as EtOH, THF, $CHCl_3$, Acetone and HCl. Main peaks of photofluorescence of Spiropyran-SBA-15 exhibited blue shift in the range of 603.4~592.1 nm after exposure under EtOH, THF, $CHCl_3$, and Acetone vapors. Normalized peak intensities decreased in the range of 0.8~0.3. The main peak of photofluorescence of Spiropyran-SBA-15 showed significant blue shift of 592.1 nm after exposure under HCl vapor, while normalized peak intensity decreased to 0.1.