• 한국염색가공학회지
• /
• 제24권2호
• /
• pp.97-105
• /
• 2012

Compared with conventional adsorption-based coloration, the photoreactions of dyes such as photo-copolymerization and photo-crosslinking under UV irradiation can be employed for the coloration of textiles, which can be carried out without salt addition at room temperature. C.I. Reactive Black 5, a homo-bifunctional reactive dye containing two sulfatoethylsulfone groups, is used as a photo-reactive dye for wool fibers. Upon UV irradiation, the photo-reactive dye was grafted onto wool fabrics without photoinitiators. Since the disulfide bonds in the cystine residues of wool can be easily photodecomposed to active thiyl radicals which initiate the polymerization, the dye can be polymerized to an oligomeric dye of a degree of polymerization of 12 or more. The grafted fabrics reached a grafting yield of 2.3% o.w.f. and a color yield (K/S) of 18.2 by the photografting of an aqueous dye concentration of 9% using a UV energy of 25J/$cm^2$. Furthermore, the photochemically dyed wool fabric showed higher colorfastness properties to light, laundering and rubbing comparable to conventional reactive dyeing.

• 한국응용과학기술학회지
• /
• 제36권1호
• /
• pp.305-311
• /
• 2019

높은 함수율을 갖는 소프트렌즈를 제조하기 위하여 아크릴계 공중합체를 설계, 제조하였다. 공중합체용 모노머로 2-hydroxyethyl methacrylate(HEMA)를 사용하였고 가교제로는 ethylene glycol dimethacrylate(EGDMA), glycerol dimethacrylate(GD) 혹은 glycerol 1,3-diglycerolate diacrylate(GDD)를 이용하여 렌즈를 제조하였다. 함수율 측정결과, 고함수율 렌즈는 기존의 36%에서 46%로 높게 나타났으며 접촉각도 38.6 에서 34.4 로 낮아져 표면 친수성이 높게 나타남을 확인하였다. 인장강도는 가교제의 친수성이 증가함에 따라 0.1MPa 에서 0.08 그리고 0.05 로 감소하였고 전자현미경으로 렌즈의 단면을 확인한 결과 상분리 현상은 나타나지 않았다. 광중합은 Real-time infrared(RTIR)로 측정하였는데 초기 중합 속도가 가교제에 따라 0.6 에서 0.9 로 나타났다.

• 생체재료학회지
• /
• 제22권4호
• /
• pp.235-248
• /
• 2018

Background: Injectable hydrogels have been extensively researched for the use as scaffolds or as carriers of therapeutic agents such as drugs, cells, proteins, and bioactive molecules in the treatment of diseases and cancers and the repair and regeneration of tissues. It is because they have the injectability with minimal invasiveness and usability for irregularly shaped sites, in addition to typical advantages of conventional hydrogels such as biocompatibility, permeability to oxygen and nutrient, properties similar to the characteristics of the native extracellular matrix, and porous structure allowing therapeutic agents to be loaded. Main body: In this article, recent studies of injectable hydrogel systems applicable for therapeutic agent delivery, disease/cancer therapy, and tissue engineering have reviewed in terms of the various factors physically and chemically contributing to sol-gel transition via which gels have been formed. The various factors are as follows: several different non-covalent interactions resulting in physical crosslinking (the electrostatic interactions (e.g., the ionic and hydrogen bonds), hydrophobic interactions, ${\pi}$-interactions, and van der Waals forces), in-situ chemical reactions inducing chemical crosslinking (the Diels Alder click reactions, Michael reactions, Schiff base reactions, or enzyme-or photo-mediated reactions), and external stimuli (temperatures, pHs, lights, electric/magnetic fields, ultrasounds, or biomolecular species (e.g., enzyme)). Finally, their applications with accompanying therapeutic agents and notable properties used were reviewed as well. Conclusion: Injectable hydrogels, of which network morphology and properties could be tuned, have shown to control the load and release of therapeutic agents, consequently producing significant therapeutic efficacy. Accordingly, they are believed to be successful and promising biomaterials as scaffolds and carriers of therapeutic agents for disease and cancer therapy and tissue engineering.

• 공업화학
• /
• 제5권5호
• /
• pp.857-861
• /
• 1994

독성이 있는 아크릴 모노머를 비닐에테르로 대체시켜 우레탄아크릴레이트와 배합시키는 것을 특징으로 하는 자외선 경화형 하이브리드 시스템을 조사하였다. 일반적으로 하이브리드 시스템의 코팅 물성은 자유 라디칼계보다은 우수하나 양이온계보다는 열세하게 나타났다. 아크릴계 올리고머 함량이 70% 이상으로 배합된 경우의 하이브리드계는 코팅물성과 경화물성면에서 자유라디칼계와 양이온계보다 뛰어나게 나타났다. 다양한 코팅 시스템의 경화과정을 조사하기 위해서 광열분석기를 적용하였다. 그 결과 코팅 배합물의 경화속도에 미치는 결정적인 인자는 배합물 특성에 따라 달라짐을 알 수 있었다. 동류의 하이브리드계의 경우에는 광경화개시제의 효율보다는 모노머/올리고머 비가 더욱 중요함을 알 수 있었다.

• Macromolecular Research
• /
• 제12권4호
• /
• pp.352-358
• /
• 2004

For their application as one-component photoresists, we prepared epoxy terpolymers containing oxime-urethane and benzophenone groups by the radical polymerization of glycidyl methacrylate (GMA), metha-cryloxyethyl benzophenoneoxime urethane (MBU), and N-(4-benzoyl)phenylmaleimide (BPMI). The terpolymer composition was optimized to provide the most photosensitive photoresist. The photo-decomposition reaction of the oxime-urethane groups in the terpolymer was monitored by UV absorption spectroscopy, and the photo-crosslinking reaction of the epoxy terpolymer was observed by measuring the normalized thickness. The photosensitivity of the epoxy terpolymer increased as the amount of BPMI and MBU units increased up to 16 and 24 mol%, respectively. Among the terpolymers we prepared, terpolymer T-II(contents of GMA, MBU, BPMI are 75, 19, 6.1 mole%, respectively) exhibited the highest photosensitivity ( $D_{c}$ $^{0.5}$ = 430 mJ/$\textrm{cm}^2$) and had a moderate contrast (${\gamma}$$^{p}$ = 1.23). Negative-tone micropatterns having a line width of ca. 10 ${\mu}{\textrm}{m}$ were obtained by developing the system with chloroform.m.

• Korean Chemical Engineering Research
• /
• 제59권1호
• /
• pp.112-117
• /
• 2021

본 연구에서는 생물학적 공유결합인 다이타이로신 결합을 모방하여 비가역적 공유결합을 기반으로 한 펩타이드의 자기조립 방법을 연구하였다. 고밀도의 다이타이로신 결합을 달성하기 위해 Tyr-Tyr-Leu-Tyr-Tyr (YYLYY) 의 서열을 갖는 펩타이드 단량체를 선택하였다. 다이타이로신 결합으로 자기조립 된 펩타이드 나노입자는 가시광선 하에서 Ru(BPY)3Cl2 촉매를 사용하여 단일공정 광가교를 통해 합성되었다. 펩타이드 나노 입자의 크기에 대한 각 성분의 농도 효과는 동적 광산란, UV-Vis 분광법 및 투과 전자 현미경을 사용하여 확인하였다. 이를 통해 130 nm~350 nm범위의 펩타이드 나노입자의 크기별 최적의 합성 조건을 제시하였다.

• 한국정밀공학회지
• /
• 제27권3호
• /
• pp.135-141
• /
• 2010

Researchers continue to explore possibilities for expanding additive manufacturing (AM) technologies into direct product manufacturing. One limitation is in the materials available for use in AM that can meet the needs of end-use applications. Stereolithography (SL) is an AM technology well known for its precision and high quality surface finish capabilities. SL builds parts by selectively crosslinking or solidifying photo-curable liquid resins, and the resin industry has been continuously developing new resins with improved performance characteristics. This paper introduces a unique SL machine that can fabricate parts out of multiple SL materials. The technology is based on using multiple vats positioned on a rotating vat carousel that contain different photo-curable materials. To change the material during the process, the build platform is raised out of the current vat, a new vat with a different material is rotated under the platform, and the platform is submerged into the new vat so that the new material can be used. This paper introduces a new vat exchange mechanism, cleaning process, recoating process, resin leveling mechanism and process planning technologies for the implementation of multiple material SL. An overview of the system framework is provided and the system integration and control software is described. In addition, several multiple material test parts are designed, fabricated, and described.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.147-148
• /
• 2006

A research on scaffold fabrication has been progressed in many research groups. However, the mechanical properties of existing biodegradable materials are still not satisfactory. But, PPF (poly (propylene fumarate)) has a good mechanical property in comparison to other biodegradable materials. Nevertheless, the viscosity of the synthesized PPF is too high to fabricate structures using micro-stereolithography. Therefore, the viscosity of the resin was made low by adding the diethyl fumarate and this material could be used in micro-stereolithography apparatus. Then, a photoinitiator was added for photo crosslinking of the DEF/PPF resin. 2.5D and 3D scaffolds were fabricated our system and curing characteristics of the resin were analyzed through the experiment.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2009년도 추계학술대회 논문집
• /
• pp.150-153
• /
• 2009

Anion exchange polymer electrolyte pore-filling membranes consisting of the whole hydrocarbon materials were prepared by photo polymerization with various quaternary ammonium cationic monomers and characterized on the properties for applying to solid alkali fuel cell (SAFC). Hydrocarbon porous substrates such as polyethylene were used for the preparation of the pore-filling membranes. The hydroxyl ion conductivity of the polymer electrolyte membranes prepared in this research was dependent on the composition ratio of an electrolyte monomer and crosslinking agents used for polymerization. Furthermore, these pore-filling membranes have commonly excellent properties such as smaller dimensional affects when swollen in solvents, higher mechanical strength, lower fuel crossover through the membranes, and easier preparation process than those of traditional cast membranes.

• 접착 및 계면
• /
• 제11권2호
• /
• pp.57-62
• /
• 2010

광원경화형 소재는 UV, 가시광선 등에 의해 반응하여 분자간의 가교가 일어나고 이러한 가교반응에 의해 물성이 제어되는 소재를 의미한다. 광원경화거동과정에서 수축현상이 발생하게 되는데 이때 발생하는 수축현상으로 인해 재료의 구조가 변하고 내부의 응력이 발생하는 현상 등의 문제가 발생한다. 열경화에 의한 수축현상을 분석하는 연구는 많이 진행되어 왔으나 광원경화에 대한 수축현상을 연구하는 분야는 현재 경화 수준이나 경화속도 등을 분석하는데 그치고 있다. 본 연구에서는 수축률 측정기를 통해 광원경화에 대한 수축현상을 실시간으로 살펴보고 재료의 차이에 따른 경화거동과 수축현상의 차이를 살펴보고자 한다. 관능기의 숫자가 변화함에 따라 수축률과 수축 속도의 변화가 생겼으며 분자량의 사슬길이에 따라 수축정도의 차이가 발생했다. 이러한 결과가 이론적인 결과 값인 양의 상관관계와는 반대로 음의 상관관계를 가짐을 분석하였다. 이는 수축률이 단순히 분자량과 관능기 숫자에 따라 결정되는 것이 아니라 분자구조에 따른 혼합물 내에서의 유동성 등에도 영향을 받음을 확인 할 수 있는 결과이다.