• 한국수소및신에너지학회논문집
• /
• 제26권3호
• /
• pp.212-220
• /
• 2015

The engineering plastic of sulfonated polyether ether ketone (SPEEK) as a polymer matrix has been developed in this lab to replace Nafion, solid polymer electrolytes of perfluorosulfonic acid membrane which has several flaws such as high cost, and limited operational temperature above $80^{\circ}C$. The SPEEK was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted tungstosilicic acid (Cs-TSiA) with cross-linking agent contents of 0.01 mL. In conclusion, CL-SPEEK/Cs-TSiA/ceria 1% membrane showed the optimum results such as 0.1882 S/cm of proton conductivity at $80^{\circ}C$, and 99.61 MPa of tensile strength which were better than Nafion 117 membrane.

• 한국수소및신에너지학회논문집
• /
• 제25권2호
• /
• pp.151-160
• /
• 2014

CL-SPEEK/Cs-TPA/$CeO_2$ composite membrane was prepared for polymer electrolyte membrane water electrolysis (PEMWE). In order to improve the electrochemical, mechanical, durabilities and electrocatalytic characteristics, engineering plastic of polyether ether ketone (PEEK) as polymer matrix was sulfonated and the organic-inorganic blend composite membranes was prepared by loading cesium-substituted tungstophosphoric acid (Cs-TPA) by titration method with cross-linking agent contents of 0.01mL. Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the PEMWE circumstance and to increase the duration of the membrane. CL-SPEEK/$Cs_{(1)}$-TPA/CeriaIn conclusion, 1% membrane showed the optimum results such as 0.119 S/cm at $80^{\circ}C$ of proton conductivity and 62MPa of tensile strength.

• 폴리머
• /
• 제37권2호
• /
• pp.167-176
• /
• 2013

디올 성분으로 폴리(테트라메틸렌 글리콜)(PTMG)과 함께 말단에 히드록시에틸기를 갖는 폴리디메틸실록산(PDMS-OH)을 혼합하여 사용하면서, 이소시아네이트 화합물로 이소포론 디이소시아네이트를, 수분산성을 부여하기 위해 디메틸올 프로피온산을, 가교제로 트리메틸올프로판을, 사슬연장제로 부탄디올을 사용하여 실록산 성분을 포함하는 선형 및 가교형 수분산성 폴리우레탄(WPU-Si)을 합성하였다. PTMG와 PDMS-OH 혼합 비율을 달리하여 합성한 선형 및 가교형 WPU-Si 에멀젼의 안정성을 분석하였고, 이들을 필름으로 제조하여 표면 특성과 $T_g$, 인장 강신도 변화를 분석하였다. PDMS 함량이 많아질수록 시료의 소수성이 증가하고 $T_g$가 높아졌으며, 파단 인장강도는 증가하고 파단 신장률은 감소하였다.

• 한국수소및신에너지학회논문집
• /
• 제23권5호
• /
• pp.437-447
• /
• 2012

Ceria ($CeO_2$) was used to scavenge free radicals which attack the membrane in the polymer electrolyte membrane water electrolysis (PEMWE) circumstance and to increase the duration of the membrane. In order to improve the electrochemical, mechanical and electrocatalytic characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK) and the organic-inorganic blended composite membranes were prepared by sol-gel casting method with loading the highly dispersed ceria and cesium-substituted tungstophosphoric acid (Cs-TPA) with cross-linking agent contents of 0.01 mL. In conclusion, CL-SPEEK/Cs-TPA/ceria (1%) membrane showed the optimum results such as 0.130 S/cm of proton conductivity at $80^{\circ}C$, 2.324 meq./g-dry-membrane of ion exchange capacity and mechanical characteristics, and 65.03 MPa of tensile strength which were better than Nafion 117 membrane.

• 한국유가공학회:학술대회논문집
• /
• 한국유가공기술과학회 2005년도 창립 30주년 기념 국제심포지움 - 웰빙시대의 우유.유제품의 새로운 발견
• /
• pp.37-61
• /
• 2005

미세캡슐 (microencapsulation)은 내부 물질(core material)의 방출을 제어하기 위하여 여러 천연 및 생분해성 물질이 사용된다. 유청단백질은 이러한 목적에 아주 적합한 것으로 여겨지고 있는데 이는 독특한 이화학적 특성에 기인되는 것이다. 본 연구팀은 drug이나 생리활성물질을 피복하기 위하여 cross-linking 물질로 glutaraldehyde를 사용하여 수용성 이면서 유청단백질을 근간으로 하는 미세캡슐 제조기술을 개발하였다. 또한 생리적 조건에서 이들 캡슐의 분해 및 포집물질의 방출에 대한 연구를 수행하였는데 수용성 drug으로 사용된 theophylline은 유청단백질에 잘 분산되는 것으로 확인되었다. 이 분산액은 !%의 생리활성물질인 polyurethane을 함유하는 dichloromethane과 hexane 혼합불에 잘 확산이 되었다. 미세캡슐공정에서 피복물질로 사용되는 여러 물질중에서 유청단백질은 생리적 효능이 뛰어나고 여러 물리적 작용이 있기 때문에 새로운 피복소재로써 그 효용성이 매우 높다. 지금까지의 연구결과 유청단백질을 이용한 미세캡슐의 제조는 유청단백질이 가지는 기능적 효과와 내부물질이 지니는 약리효과를 동시에 이용할 수 있다는 점에서 향후 고부가 식품 의약품 첨가물질로써 유용성이 기대된다고 하겠다.

• 통합자연과학논문집
• /
• 제8권1호
• /
• pp.60-66
• /
• 2015

The physical and optical properties of polymers with 2-fluoroaniline and 4-fluoroaniline added, which can be used for hydrophilic ophthalmic lenses, were investigated in this study. The UV-blocking properties of 2- and 4-fluoroaniline were also investigated by measuring their UV transmissibility. 2- and 4-Fluoroaniline were used as additives for the basic combination of HEMA, 5% AA, and 1% MMA, and the materials were copolymerized with EGDMA as the cross-linking agent and AIBN as the initiator. The refractive index, water content, optical transmittance, tensile strength, and contact angle were measured to evaluate the physical properties of the produced hydrogel lens. The measured physical properties of the hydrogel contact lens produced with the copolymerized polymer showed a refractive index of 1.425-1.436; a water content of 36.95-44.65%; a visual light transmittance of 66.0-81.0%; a tensile strength of 0.138-0.281 kgf; and a contact angle of $55.02-57.87^{\circ}$. The UV transmissibility was significantly reduced, which indicates that 2-fluoroaniline and 4-fluoroaniline have UV-blocking properties. This study showed that 2- and 4-fluoroaniline are expected to be used as UV-blocking materials in hydrogel ophthalmic lenses whose physical properties, such as their refractive index and water content, do not change.

• 한국재료학회지
• /
• 제28권8호
• /
• pp.452-458
• /
• 2018

This research is conducted to create a functional hydrogel ophthalmic lens containing nanoparticles. Carbon nanoparticles and PEGMEMA are used as additives for the basic combination of HEMA, MA, and MMA, and the materials are copolymerized with EGDMA as the cross-linking agent and AIBN as the thermal initiator. The hydrogel lens is produced using a cast-mold method, and the materials are thermally polymerized at $100^{\circ}C$ for an hour. The polymerized lens sample is hydrated in a 0.9 % saline solution for 24 hours before the optical and physical characteristics of the lens are measured. The refractive index, water content, contact angle, light transmittance, and tensile strength are measured to evaluate the physical and optical characteristics of the hydrogel lens. The refractive index, water content, contact angle, UV-B light transmittance, UV-A light transmittance, visible light transmittance, tensile strength and breaking strength of the hydrogel lens polymer are 1.4019~1.4281, 43.05~51.18 %, $31.95{\sim}68.61^{\circ}$, 21.69~58.11 %, 35.59~84.26 %, 45.85~88.06 %, 0.1075~0.1649 kgf and 0.1520~0.2250 kgf, respectively. The results demonstrate an increase in refractive index, tensile strength and breaking strength and a decrease in contact angle and light transmittance. Furthermore, the visible light transmissibility is significantly increased at PEG 10 %. It is clear that this material can be used for high-performance ophthalmic lenses with wettability, ultraviolet ray blocking effect, and tensile strength.

• Bulletin of the Korean Chemical Society
• /
• 제23권11호
• /
• pp.1616-1622
• /
• 2002

If the surfaces of vesicles are chemically modified so that they can be dispersed in organic solvents, the application of vesicular colloids may be expanded. A polymerizable surfactant (BDAC) and nonpolymerizable bipolar surfactant (BPAS) were synthesized in multi-steps. Large vesicles composed of BDAC and BPAS with embedded a cross-linking agent (divinylbenzene) underwent a radical polymerization. BPAS was extracted out using methanol (skeletonization). The headgroup of BDAC was cleaved off via hydrolysis in an acidic condition to yield vesicles where surfaces were covered with -COOH groups. There was no significant change in the overall shape. The skeletonized vesicles appear to have many holes with diameters up to about 25 nm. The holes retained even after hydrolysis. The hydrolyzed vesicles were not dispersed in water and most organic solvents such as tetrahydrofuran and chloroform, but dispersed in methanol.

• 패션비즈니스
• /
• 제13권1호
• /
• pp.115-124
• /
• 2009

Chitosan and CA/BTCA were employed in order to induce crosslinking in the fiber for the improvement of wrinkle recovery of the cotton fabrics and the endowment of anti-microbial functions to the fabric. The treated fabrics were dyed by using reactive dyestuff and their dyeing behaviors were investigated. As a result, the fabric treated with chitosan only exhibited more dye-uptake amount than the untreated fabric, and the treated and untreated fabrics together showed excellent light-fastness and wash-fastness. In the cases that CA or BTCA was added to the chitosan, the CA-treated showed better dye-uptake and dyeing properties as light-fastness than the BTCA-treated. In conclusion, it is possible to maintain the dye-uptake level at reduced treatment cost when the CA is employed as a substitute cross-linking agent for BTCA.

• 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.