• 폴리머
• /
• 제31권3호
• /
• pp.255-262
• /
• 2007

고분자 습도센서 막으로 사용하기 위한 두 가지 타입의 공중합체를 라디칼 중합방식에 의하여 제조하였다. 각각 공중합체는 세 가지의 단량체를 포함하여 제조하였는데, 각 단량체들은 습도 저항성, 막 안정성, 유연성, 임피던스 및 전극 부착력을 증대시키는 효과를 가지도록 하였다. 염 형태의 MDBAB는 제조된 습도 막의 임피던스를 감소시키는 효과를 보였으며 아민과 반응하여 가교 구조를 생성하였다. DAEMA, 4-VP, 및 2-EHA를 사용하여 습도막 제조를 위하여 몇 가지 조성물을 제조하였다. 특정 조성 조건에서 성능 및 장기 내구성 측면에서 우수한 결과를 얻을 수 있었다.

• 한국안광학회지
• /
• 제19권2호
• /
• pp.145-151
• /
• 2014

목적: 개시제와 교차결합제의 농도에 따른 소프트콘택트렌즈의 재질을 변화시켜서 재질변화에 대한 물리적 특성 및 약물의 용출량 및 속도를 비교하였다. 방법: HEMA에 개시제인 AIBN과 교차결합제인 EGDMA의 농도을 변화시켜서 콘택트렌즈를 제작하였다. 항균물질인 노플록사신(norfloxacin)은 고분자 중합 시 0.1% 농도로 단량체와 함께 혼합하였다. 재질변화에 따른 물리적 성질 변화를 확인하기 위해 약물용출 농도, 함수율, 굴절률, 단백질 흡착량 등에 대한 실험을 통하여 비교하였으며, 통계분석을 통해 유의성을 확인하였다. 결과: 개시제의 농도을 변화 시킨 콘택트렌즈는 함수율의 변화가 거의 없으며, 굴절률의 값에도 별 변화가 없었다. 교차결합제 농도이 증가하면 함수율이 낮아지고 굴절률이 높아졌다. 약물용출의 농도를 살펴보면 개시제의 변화에 의해서는 많은 변화를 보이지 않았으며, 함수율이 높을수록 용출되는 농도가 증가하였다. 단백질 흡착양은 개시제에 의한 변화는 거의 없었으며 함수율이 낮을수록 흡착되는 양이 증가하였다. 결론: 개시제의 농도에 대한 변화는 특성 변화에 영향력이 거의 없었으며, 교차결합제 농도에 따라서는 많은 변화를 보였다. 교차결합제의 농도가 증가할수록 함수율은 감소하며 굴절률은 증가하였다. 또한 함수율의 증가에 따라 약물이 많이 용출되었으며 단백질의 흡착량은 감소되었다.

• 대한치과기공학회지
• /
• 제29권1호
• /
• pp.121-131
• /
• 2007

A preparation process's conditions of aqueous sol which contains anatase-type nano titania particles with photocatalyic properties was established by using Yoldas process, so called, DCS(Destabilization of Colloidal Solution) process in this study. And crystal size change and phase transformation of titania particles in aqueous titania sol depending on reaction conditions was investigated by a light scattering method and XRD analysis of frozen dried powders, respectively. This sol with photo catalytic nano titania particles was used to the following hydrophilic hybrid coating film's fabrication and its properties was evaluated. Subsequently, for coating film using the above mentioned aqueous titania sol, non-aqueous titania sol was prepared without any chemical additives and its time stability according to aging time was investigate. By using the above mentioned aqueous titania sol and non-aqueous sol, a complex oxide coating sol for metal and ceramic substrate and a organic-inorganic hybrid coating sol for polymer substrate was prepared and it's hydrophilicity depending on UV irradiation conditions was evaluated. As a conclusions, the following results were obtained. (1)Aqueous titania sol The average particle size of titania in formed aqueous titania sol was distributed between 20$\sim$90nm range depending on reaction conditions. And the crystal phase of titania powders obtained by frozen drying method was changed from amorphous state to anatase and subsequently transformed to rutile crystal phase and it is attributed to concentration gradient in aqueous sol. (2)Non-aqueous titania sol Non-aqueous titania sol was prepared using methanol as a solvent and a little distilled water for hydrolysis and nitric acid as a catalyst were used. The obtained non-aqueous titania sol was stable at room temperature for 20 days. Additionally, non-aqueous titania sol with addition of chealating reagent such as acethylaceton and ethylene glycol prolonged the stability of sol by six months. (3)Complex sol and hybrid sol with super hydrophilicity The above mentioned aqueous titania sol as a main photocataylic component and non-aqueous titania sol as a binder for coating process was used to prepare a complex sol used for metal, ceramic and wood material substrate and also to prepare the organic-inorganic hybrid sol for polymer substrate such as polycarbonate and polyethylene, in which process APMS(3-Aminopropyltrimethoxysilane), GPTS(3-Glycidoxypropyl-trimethoxysilane) as a hydrophilic silane compound and HEMA(2-Hydroxyethyl methacrylate) as a forming network in hybrid coating film were used. The hybrid coating film such as prepared through this process showed a superhydrophilicity below 1$10^{\circ}$ depending on processing conditions and a pencil's hardness over 6 H.

• 한국안광학회지
• /
• 제19권1호
• /
• pp.43-49
• /
• 2014

목적: 본 연구는 glycerin과 PVP(polyvinylpyrrolidone)을 각각 첨가제로 사용하였을 때 친수성 콘택트렌즈의 물성 변화를 평가하였다. 방법: Glycerin과 PVP(polyvinylpyrrolidone)를 각각 첨가제로 사용하여 교차결합제인 EGDMA (ethylene glycol dimethacrylate) 기본적인 모노머인 HEMA(2-hydroxyethyl methacrylate)와 그리고 개시제인 AIBN(azobisisobutyronitrile)을 기본 조합으로 하여 공중합하였다. 결과: 생성된 고분자의 물리적 특성을 측정한 결과 PVP(polyvinylpyrrolidone)의 경우, 굴절률은 1.4382~1.4288로, 인장강도는 0.3446~0.2542 kgf로 각각 감소하였으며, 접촉각은 21.44% 감소되고 함수율은 13.49% 증가하였다. 또한 glycerin의 경우, 굴절률 1.4330~1.4328로, 인장강도는 0.2974~0.2854 kgf로, 함수율은 35.58~36.53%로 큰 변화를 보이지 않았으며, 접촉각의 경우 37.64%가 감소되었다. 결론: 본 실험결과로 볼 때, 생성된 공중합체는 고 습윤성 안 의료용 렌즈 재료로 사용이 가능하며, 또한 glycerin을 첨가제로 사용하였을 때, 함수율과 굴절률의 변화를 최소화시킴과 동시에 친수성 렌즈의 습윤성을 증가시켰다.

• 한국안광학회지
• /
• 제20권2호
• /
• pp.125-131
• /
• 2015

목적: 본 연구에서는 써클콘택트렌즈의 착색이 눈물막 안정성에 미치는 영향을 알아보고자 하였다. 방법: 눈물량이 정상인 20대 54안을 대상으로 콘택트렌즈 착용 전후의 비침입성 눈물막파괴시간 및 눈물막 깨짐이 시작되는 부위를 측정하였으며, 콘택트렌즈 전후면의 표면 거칠기를 주사전자현미경으로 관찰하였다. 콘택트렌즈는 hilafilcon B재질의 투명 및 써클콘택트렌즈, polymacon 재질 및 HEMA NVP 공중합 재질의 써클콘택트렌즈를 대상으로 하였다. 결과: 콘택트렌즈 착용 시 나안에 비해 눈물막파괴시간이 통계적으로 유의하게 감소하였으며 써클콘택트렌즈 간에 눈물막파괴시간이 통계적으로 유의한 차이를 보이는 경우도 있었다. 일반적으로 콘택트렌즈의 상방부 보다는 하방부에서, 코방향 보다는 귀방향에서 좀 더 높은 빈도로 눈물막이 깨지기 시작하였으나 렌즈의 종류에 따라 다소 차이가 있었다. Hilafilcon B 투명렌즈에 비해 동일 재질 써클콘택트렌즈 주변부(착색부분)에서의 눈물막 깨짐이 더 많았다. 결론: 써클콘택트렌즈의 착용으로 인해 눈물막 안정성이 영향을 받음을 알 수 있었으며, 본 연구결과는 써클콘택트렌즈 착용 시 착색으로 인하여 나타날 수 있는 문제점 해결의 기초자료로 사용될 수 있을 것으로 보인다.

• 한국응용과학기술학회지
• /
• 제21권3호
• /
• pp.197-203
• /
• 2004

Acrylic resins ($HSC_s$ : EA/EMA/2-HEMA/CLA) which contain 70% solid content were synthesized by the copolymerization of monomers (2-hydroxyethyl methacrylate, ethyl acrylate, and ethyl methacrylate) and functional monomer (caprolactone acrylate : CLA) which improves the crosslinking density and physical properties of films. The physical properties of the prepared acrylic resins (HSCs) containing CLA, are as follows : viscosity 245${\sim}$515 cps ; $M_n$ 2670${\sim}$2840 ; and conversions, 83${\sim}$91%, respectively. From the correlation of $T_g$ values, viscosities, and $M_n$ of the HSCs, it was found that viscosity and $M_n$ increased with $T_g$ value.

• 한국응용과학기술학회지
• /
• 제20권3호
• /
• pp.221-229
• /
• 2003

A copolymer ${\sim}$550cps ; $M_n$, 2590${\sim}$2850 ; and conversion, 82${\sim}$89%, respectively. It was found from the plotting of $T_g$ versus viscosity and $T_g$ versus molecular weight that viscosity increased with $T_g$ while number averaged molecular weight decreased with increasing $T_g$.

• 한국응용과학기술학회지
• /
• 제23권1호
• /
• pp.85-91
• /
• 2006

Acrylic resins (HSCs : EA/EMA/2-HEMA/CLA) which contain 80% solid content were synthesized by the copolymerization of monomers (ethyl acrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate) and functional monomer (caprolactone acrylate : CLA) which improves the crosslinking density and physical properties of films. The physical properties of the prepared acrylic resins (HSCs) containing CLA, are as follows: viscosity 1440$^{\sim}$2630 cps ; $M_n$ 1590$^{\sim}$1660 ; and conversions, 81$^{\sim}$86%, respectively. From the correlation of $T_g$ values, viscosities, and $M_n$ of the HSCs, it was found thst viscosity and $M_n$ increased with $T_g$ value.

• 한국재료학회지
• /
• 제29권12호
• /
• pp.735-740
• /
• 2019

The purpose of this study is to fabricate an ophthalmic lens by copolymerizing two types of carbon nanotubes and hydrophilic hydrogel lens materials, and to investigate its application as an ophthalmic lens material by analyzing its physical properties and antimicrobial effect. For polymerization, HEMA (2-hydroxyethyl methacrylate), EGDMA (ethylene glycol dimethacrylate), a crosslinking agent, and AIBN (azobisisobutyronitrile), an initiator, are used as a basic combination, and a single-walled carbon nanotube and a single-walled, carboxylic-acid-functionalized carbon nanotube are used as additives. To analyze the physical properties, the water content, refractive index, breaking strength, and antimicrobial effect of the fabricated lenses are measured. The fabricated lenses satisfies all the basic properties of the basic hydrogel ophthalmic lens. The water content increases with increasing amount of additive and decreases with addition of 0.2 % ratio of nanoparticles. The refractive index is inversely proportional to the water content result. As a result of the antimicrobial test of the fabricated lens, the addition of carbon nanotubes shows an excellent antimicrobial effect. Therefore, it is considered that the fabricated lens can be applied as a functional material for basic ophthalmic hydrogel lenses.

• 통합자연과학논문집
• /
• 제11권2호
• /
• pp.113-120
• /
• 2018

This study was planned to prepare the high strength hydrogel ophthalmic lens containing isocyanate group and nanoparticles. HDI with carbon nanoparticles were used as additives for the basic combination of HEMA, MA and MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The mixture was heated at $100^{\circ}C$ for an hour to produce the high performance hydrogel ophthalmic lens by cast mold method. Measurement of the physical characteristics of the produced material showed that the refractive index was in the range of 1.4027~1.4600, water content 25.21~44.01%, contact angle $54.18{\sim}72.94^{\circ}$, visible light transmittance 53.03~92.09%, and tensile strength 0.1024~0.2359 kgf and breaking strength was 0.0872~0.2825 kgf. The results showed an increase of refractive index while the decrease in water content. And also, the breaking strength was highest when the addition ratio of HDI was 5%(wt). As a result of the absorbance measurement, no significant difference was observed in all the samples, so it can be judged that the stabilization of nanoparticles in the polymer was maintained.