• 접착 및 계면
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• 제7권4호
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• pp.32-38
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• 2006

A series of organic-inorganic hybrids, PCL/EP/$SiO_2$, involving epoxy resin and triethoxysilane-terminated polycaprolactone elastomer (PCL-TESi) were prepared via polymerization of diglycidyl ether of bisphenol A (DGEBA) with amine curing agent KB-2 and sol-gel process of PCL-TESi. The curing reactions were started from the initially homogeneous mixture of DGEBA, KB-2 and the PCL-TESi. The organicinorganic hybrids containing up to 4.95% (wt) of $SiO_2$ were obtained and characterized by FT-IR, transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). It was experimentally shown that the swelling property in toluene, morphologies and thermal properties of the resulting hybrids were quite dependent on the contents of $SiO_2$. The crosslink network density decreases with increasing of the PCL-TESi. And in TEM, the phase separated morphology of these hybrids was found, which resulted from the coagulation of Si-O-Si networks resulting from $-Si(OC_2H_5)_3$ of PCL-TESi self-curing by hydrolytic silanol condensation, with the advancement of the curing reaction in the modified epoxy resin systems. Meanwhile, the change of the $SiO_2$ content made the morphologies changed from aggregated particles of Si-O-Si in the hybrid to nanocluster of interconnected Si-O-Si particles, then to aggregated Si-O-Si dispersing in the continuous cured epoxy phase again, and last to co-continuous interpenetrating network. The glass transition behavior of the hybrid material was cooperative motion of large chain segments, which were hindered by the inorganic Si-O-Si network. And in TG analysis, the characteristic temperature at 5% of weight loss was evidently increased from $120.5^{\circ}C$ of pure cured epoxy to $277.6^{\circ}C$ of 3.84% (wt) of $SiO_2$ modified epoxy due to the existence of Si-O-Si when PCL-TESi was added in the hybrid.

• 한국CDE학회논문집
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• 제13권6호
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• pp.421-428
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• 2008

This article investigates the fabrication of polycaprolactone (PCL) composites filled with different volume fractions (10-30%) of tricalcium phosphate (TCP) by selective laser sintering (SLS) for tissue engineering scaffolds. Optimal processing parameters for each composition were developed by design of experiments (DOE). Specimens for compressive testing for each composition were fabricated and tested. The results showed that the compressive modulus increases as a function of TCP volume fraction. The experimentally measured compressive moduli were compared with moduli predicted by Halpin's theoretical model and were found to be in excellent agreement. This result proved that experimentally determined processing parameters for each composition were well optimized.

• 폴리머
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• 제24권2호
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• pp.141-148
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• 2000

Polycaprolactone (PCL)을 base로 하는 효과적인 compost 필름을 만들기 위하여 옥수수전분을 블렌딩한 뒤 기계적 특성과 미생물에 의한 생분해도를 조사하였다. 비상용성을 보이는 옥수수전분/PCL 블렌드에 대한 상용화제로는 2-hydroxyethylmethacrylate (HEMA)-PCL macromer를 옥수수전분에 그래프팅시킨 공중합체를 사용하였는데 옥수수전분에 대한 HEMA의 그래프팅율이 가장 높은 것과 가장 낮은 것을 선택하여 일정한 조성의 $\varepsilon$-caprolactone에 그래프팅시킨 상용화제들의 상용화 효과를 비교하였다. 상용화제를 함유한 옥수수전분/PCL (50/50) 블렌드의 신장율이 상당히 증가하였으며 SEM 관찰 결과 이는 상용화제로 인해 옥수수전분 알갱이와 PCL 기질간의 계면 접착력이 증가하였기 때문으로 판단된다. 그러나 모듈러스와 인장강도는 상용화치 사용에도 불구하고 별다른 변화가 없었다.

• 폴리머
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• 제38권6호
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• pp.815-819
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• 2014

조직공학에서의 인공지지체는 세포의 부착과 증식 및 분화가 잘 되어야 하고, 우수한 생체친화성 및 생분해성을 지녀야 한다. 다양한 인공지지체 제작 방법이 시도되어지고 있으며, 최근들어 3D 프린팅 기술을 이용한 방식이 활발하게 연구되어지고 있다. 폴리카프로락톤(polycaprolactone, PCL)은 낮은 녹는점을 가지고 있어 3D 프린팅하기에 우수한 생체적합 고분자 합성재료이다. 본 연구에서는 3D 프린팅 기술을 이용하여 3차원 PCL 인공지지체를 제작하였고, 지지체의 표면개질을 위해 수산화나트륨(NaOH)을 이용하였다. 표면개질된 인공지지체의 표면특성을 SEM으로 확인한 결과, 수산화나트륨을 처리한 PCL 인공지지체가 처리하지 않은 PCL 인공지지체에 비해 거칠기가 증가함을 보였으며, 접촉각 측정을 통해 친수성이 증가함을 확인하였다. In vitro 실험결과, 수산화나트륨을 처리한 PCL 인공지지체가 처리하지 않은 PCL 인공지지체에 비해 세포의 증식과 분화가 증가함을 보였고, 세포의 부착 모습은 균일하고 밀집된 형태로 부착됨을 확인하였다. 따라서 조형가공기술을 이용하여 수산화나트륨을 처리한 표면개질된 PCL 인공지지체를 제작하고 분석함으로써, 세포적합성을 통해 체내 인공지지체 개발 적용 가능성을 제시하였다.

• 멤브레인
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• 제26권1호
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• pp.26-31
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• 2016

폴리카프로락톤(PCL)에 NaCl을 혼합한 용액을 블레이드법에 의하여 막형태로 제조한 후 NaCl을 추출하는 염출법을 이용하여 조직공학적으로 사용할 3차원 다공망을 갖는 멤브레인 형태의 지지체를 제조하였다. 본 연구에서는 성형된 멤브레인의 건조조건과, NaCl 입자의 크기, NaCl의 혼합량을 각각 다르게 하여 제조하였다. 별도로 제작한 고분자용액 공급장치를 이용하여 PCL/클로로포름($CHCl_3$) 용액에 NaCl 입자가 균일하게 혼합된 용액을 유리판에 분주하여 필름 어플리케이터를 사용하여 블레이드법에 의한 멤브레인을 제조하였다. 멤브레인 지지체에는 NaCl 입자에 의한 거대기공과 거대기공을 이루는 구조벽에서는 $CHCl_3$의 증발에 의한 미세기공이 함께 복합적으로 상호 연결되어 형성되었다.

• 멤브레인
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• 제27권6호
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• pp.511-518
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• 2017

막유화(membrane emulsification, ME)는 SPG 막과 같이 균일한 크기의 세공을 갖는 막을 사용하여 좁은 입도분포의 에멀젼을 제조하는 기술이다. 본 연구에서는 막유화법으로 형성시킨 다중 에멀젼을 사용하여 폴리카프로락톤(PCL) 마이크로캡슐의 제조를 연구하였다. 먼저 초음파 유화기로 $W_1/O$ 단일 에멀젼을 제조한 후, premix 막유화를 적용하여 $W_1/O/W_2$ 다중 에멀젼을 형성시킨 후 용매 증발을 통해 모델 약물인 BSA가 담지된 PCL 마이크로캡슐을 제조하였다. 연속상에 대한 분산상의 비율(D/C ratio), PCL 농도, 유화제 농도, 모델 약물의 농도, 막간 압력차 등 막유화 변수가 제조된 마이크로캡슐의 입경과 입도 분포에 미치는 영향을 실험하였다. Premix-ME를 적용하여 평균 입경 $5{\sim}6{\mu}m$의 균일한 크기를 갖는 모델 약물 BSA의 함침량이 약 26%인 다중 코어형 PCL 마이크로캡슐을 제조할 수 있었다.

• 한국정밀공학회지
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• 제31권9호
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• pp.791-797
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• 2014

Abstract Scaffold used as a carrier of the cell has been actively conducted using plenty of technology in tissue engineering. ${\beta}$-tricalcium phosphate (${\beta}$-TCP) material has shown good biocompatibility and osteoconductive ability when it was implanted as a bone graft substitute in osseous defect in human and animal studies for bone regeneration. In this study, we fabricated the blended polycaprolactone (PCL) and ${\beta}$-TCP scaffold by the polymer deposition system (PDS). The PCL/${\beta}$-TCP scaffold was fabricated at a temperature of $110^{\circ}C$, pressure of 650 kPa, and scan velocity of 100 mm/sec. The Overall geometry and size of the scaffold were fixed circle type with a diameter of 10 mm and a height of 4 mm. PCL/${\beta}$-TCP scaffold was observed by scanning electron microscopy. Cell attachment and proliferation of the scaffold containing 30 wt% ${\beta}$-TCP was superior to those containing 10 wt% and 20 wt% ${\beta}$-TCP.

• 한국전기전자재료학회논문지
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• 제31권4호
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• pp.238-243
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• 2018

A nanofiber was fabricated with carbon nanotubes for transparent electrodes. It was prepared with a composite solution of bio-molecules polycaprolactone (PCL) and multiwalled carbon nanotubes (MWCNTs) by electrospinning on a glass substrate, following which its electrical characteristics were investigated. The content of MWCNTs was varied during electrospinning, while that of PCL was fixed. Further, a nanometer-thick thin film of silver was deposited on the nanofiber layer using a thermal evaporator to improve the electrical characteristics; the sheet resistance significantly reduced after this deposition. The results showed that this carbon nanotube nanofiber has potential applications in biotechnology and as a flexible transparent display material.

• Journal of Microbiology and Biotechnology
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• 제27권9호
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• pp.1657-1663
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• 2017

Cosmetic patches have recently been developed as skin products for personal care owing to rapid advances in the technology of delivery of active ingredients, moisture, and adhesiveness to skin. Alginate and Spirulina are typical marine resources used in cosmetic products. This research involved the development of a Spirulina extract-impregnated alginate nanofiber cosmetic patch supported by a polycaprolactone (PCL) nanofiber cover (Spi/Alg-PCL NF patch). In addition to the ability of alginate to affect moisture and adhesiveness to skin, the impregnation of Spirulina extract strengthened those abilities as well as its own bioactive effectiveness. All fabrication processing steps were undertaken in aqueous solution. The three components (alginate, Spirulina extract, and PCL) had no detected cytotoxicity in human keratinocyte cell-based examination. In addition, wetting the pre-dried patch on the skin resulted in the Spirulina extract being released within 30 min. The results indicate the excellence of the Spi/Alg-PCL NF patch as a skin-care cosmetic device.

• 한국재료학회지
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• 제20권6호
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• pp.331-337
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• 2010

A highly porous Biphasic Calcium Phosphate (BCP) scaffold was fabricated by the sponge replica method with a microwave sintering technique. The BCP scaffold had interconnected pores ranging from $80\;{\mu}m$ to $1000\;{\mu}m$, which were similar to natural cancellous bone. To enhance the mechanical properties of the porous scaffold, infiltration of polycaprolactone (PCL) was employed. The microstructure of the BCP scaffold was optimized using various volume percentages of polymethylmethacrylate (PMMA) for the infiltration process. PCL successfully infiltrated into the hollow space of the strut formed after the removal of the polymer sponge throughout the degassing and high pressure steps. The microstructure and material properties of the BCP scaffold (i.e., pore size, morphology of infiltrated and coated PCL, compressive strength, and porosity) were evaluated. When a 30 vol% of PMMA was used, the PCL-BCP scaffold showed the highest compressive strength. The compressive strength values of the BCP and PCL-BCP scaffolds were approximately 1.3 and 2MPa, respectively. After the PCL infiltration process, the porosity of the PCL-BCP scaffold decreased slightly to 86%, whereas that of the BCP scaffold was 86%. The number of pores in the $10\;{\mu}m$ to $20\;{\mu}m$ rage, which represent the pore channel inside of the strut, significantly decreased. The in-vitro study confirmed that the PCL-infiltrated BCP scaffold showed comparable cell viability without any cytotoxic behavior.