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이광자 중합 광조형을 이용한 마이크로 부품 성형을 위한 복셀 기반 레이저 초점 이동 경로 제어
황선욱(Sun-Uk Hwang),이용구(Yong-Gu Lee) (사)한국CDE학회 2010 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2010 No.1
Two-photon photopolymerization via two-photon absorption is a promising three-dimensional microfabrication technique that has a considerable attraction. This method uses tightly focused ultra-short laser pulses to apply high energy in small volume of photo-sensitive polymer resin for subsequent photopolymerization. Because of nonlinear nature of this process, a resolution beyond diffraction limit can be realized by carefully controlling the laser pulse energy and exposure time. In this paper, we present the voxel based laser focal point positioning method for fabrication of micro-parts using two-photon photopolymerization. The proposed method can locate the laser focal point layer by layer using voxel position and exposure time can be controlled using gray level voxel value.
Self-Assembly and Photopolymerization of Diacetylene Molecules on Surface of Magnetite Nanoparticles
T. P. Vinod,김진권,이석우,Ji Hoon Chang 대한화학회 2008 Bulletin of the Korean Chemical Society Vol.29 No.4
An amphiphilic diacetylene compound was deposited on the surface of nano sized magnetite particles (Fe₃O₄) using a self-assembly method. The diacetylene molecular assembly formed on the surface of nanoparticle was subjected to photopolymerization. This resulted in the formation of a polymeric assembly on the surface of the nanoparticles in which the adjacent diacetylene molecules were connected through conjugated covalent networks. The presence of immobilized polymer species on the surface of nanoparticles is expected to protect them from agglomeration and ripening, thereby stabilizing their physical properties. In this work, Fe3O4 nanoparticles were prepared by chemical coprecipitation method and the diacetylene molecule 10,12-pentacosadiynoic acid (PCDA) was anchored to the surface of Fe3O4 nanoparticles through its carboxylate head group. Irradiation of UV light on the nanoparticles containing immobilized diacetylenes resulted in the formation of a polymeric assembly. Presence of diacetylene molecules on the surface of nanoparticles was confirmed by X-ray photoelectron spectroscopy and FT-IR measurements. Photopolymerization of the diacetylene assembly was detected by UV-Visible spectroscopy. Magnetic properties of the nanoparticles coated with polymeric assembly were investigated with SQUID and magnetic hysteresis showed superparamagnetic behaviors. The results put forward a simple and effective method for achieving polymer coating on the surface of magnetic nanoparticle.
Self-Assembly and Photopolymerization of Diacetylene Molecules on Surface of Magnetite Nanoparticles
Vinod, T.P.,Chang, Ji-Hoon,Kim, Jin-Kwon,Rhee, Seog-Woo Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.4
An amphiphilic diacetylene compound was deposited on the surface of nano sized magnetite particles ($Fe_3O_4$) using a self-assembly method. The diacetylene molecular assembly formed on the surface of nanoparticle was subjected to photopolymerization. This resulted in the formation of a polymeric assembly on the surface of the nanoparticles in which the adjacent diacetylene molecules were connected through conjugated covalent networks. The presence of immobilized polymer species on the surface of nanoparticles is expected to protect them from agglomeration and ripening, thereby stabilizing their physical properties. In this work, $Fe_3O_4$ nanoparticles were prepared by chemical coprecipitation method and the diacetylene molecule 10,12- pentacosadiynoic acid (PCDA) was anchored to the surface of $Fe_3O_4$ nanoparticles through its carboxylate head group. Irradiation of UV light on the nanoparticles containing immobilized diacetylenes resulted in the formation of a polymeric assembly. Presence of diacetylene molecules on the surface of nanoparticles was confirmed by X-ray photoelectron spectroscopy and FT-IR measurements. Photopolymerization of the diacetylene assembly was detected by UV-Visible spectroscopy. Magnetic properties of the nanoparticles coated with polymeric assembly were investigated with SQUID and magnetic hysteresis showed superparamagnetic behaviors. The results put forward a simple and effective method for achieving polymer coating on the surface of magnetic nanoparticle.
Qijian Niu,Lingwang Zeng,Xueyan Mu,Jun Nie,Guiping Ma 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.34 No.-
The objective of this work is to demonstrate the feasibility of preparation of core-shell nanofibers byelectrospinning combined with in situ UV photopolymerization. The thiol-ene monomer with Si atomand the initiator can migrate to the surface with the evaporation of the solvent during the process ofelectrospinning, which caused phase separation due to the great migration ability of small molecule andlow surface energy. Then photo induced polymerization and cross-linking reaction took placesimultaneously during the electrospinning process, which formed shell of the nanofibers. Themorphology and structure of electrospun nanofibers were investigated by SEM and TEM. Thecomposition of the shell layer was determined by ATR-IR and XPS. Moreover, the nanofiber mats weretested by WCA test, and the hydrophobic ability of PVP nanofibers was improved because of theprotection of the shell layer with Si atom. The most important thing is that the technology whichcombined electrospinning with in situ photopolymerization provides a simple method for preparation ofcore-shell nanofibers.
Novel cationic photopolymerizable propenyl ethers
김기상,심상연,제갈영순 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0
Several mono- and di-propenyl ethers were synthesized by the direct allylation of alcohols in the presence of base and a quaternary ammonium salt phase transfer catalyst. Then the allyl ethers were rearranged to the corresponding propenyl ethers using a strong base in high yield. Utilizing real-time infrared spectroscopy, the reactivity of the monomers in photoinitiated cationic polymerization was studied employing triarylsulfoniumsalts containing long-chain alkoxy group as photoinitiators. The monomers were shown to undergo very rapid photopolymerization.
황소라,이창수,최창형 한국고분자학회 2012 Macromolecular Research Vol.20 No.4
This study presents simple method for surface modification of hydrophobic poly(dimethylsiloxane)(PDMS) microchannel using combination of silane coupling and photopolymerization. The method spatially modulates the wettability and can fabricate high contrast spatial patterning of microfluidic device wettability. The physical and chemical characteristics are investigated with contact angle, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), change of meniscus of water fluid, and spatially selective immobilization of fluorescent dyes. We successfully use our method to selectively modify the surface properties in certain areas of assembled microchannel. Furthermore, our approach allows for the generation of highly monodisperse double emulsions and multiple emulsions containing various numbers of inner droplets.
마이크로채널 내 이중유화 액적 형성을 통한 마이크로캡슐 제조
남진오 ( Jin Oh Nam ),최창형 ( Chang Hyung Choi ),김종민 ( Jong Min Kim ),강성민 ( Sung Min Kang ),이창수 ( Chang Soo Lee ) 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.5
In this study, we present simple microfluidic approach for the synthesis of monodisperse microcapsules by using droplet-based system. We generate double emulsion through single step in the microfluidic device having single junction while conventional approaches are limited in surface treatment for the generation of double emulsion. First, we have injected disperse fluid containing FC-77 oil and photocurable ethoxylated trimethylolpropane triacrylate (ETPTA) and water containing 3 wt% poly(vinyl alcohol) (PVA) as continuous phase into microfluidic device. Under the condition, we easily generate double emulsion with high monodispersity by using flow focusing. The double emulsion droplets are transformed into microcapsules under the UV irradiation via photopolymerization. In addition, we control thickness of double emulsion`s shell by controlling flow rate of ETPTA. We also show that the size of double emulsions can be controlled by manipulation of flow rate of continuous phase. Furthermore, we synthesize microcapsules encapsulating various materials for the application of drug delivery systems.
Jia-An Zhang,Nian-Fa Yang,Li-Wen Yang,Shi Wu,Ye-Hui Chen,Jin Zhang 한국고분자학회 2013 Macromolecular Research Vol.21 No.6
Three new chiral bisacylphosphine oxides, (-)-bis(menthylformyl)phenylphosphine oxide (1a), (+)-bis(2,4,6-trimethylbenzoyl)menthylphosphine oxide (2a), and (-)-bis(menthylformyl)menthylphosphine oxide (3a),were synthesized using menthol as a chiral source. The synthesized new chiral bisacylphosphine oxides were used as photoinitiators for the polymerization of 1-phenyldibenzosuberyl methacrylate (PDBSMA). The polymerization initiated by chiral bisacylphosphine oxides under UV light irradiation is helix-sense-selective. Among the three prepared chiral bisacylphosphine oxides, the helix-sense-selectivity of bis(menthylformyl)menthylphosphine oxide is highest. The highest specific rotation of poly(1-phenyldibenzosuberyl methacrylate) at 365 nm is +416. The feed molar ratio of monomer to chiral bisacylphosphine oxide and the polymerization temperature have an influence on the helix-sense-selectivity. The lower the feed molar ratio of monomer to chiral bisacylphosphine oxide, the better the helix-sense-selectivity is. The increase of polymerization temperature is propitious to increase the helix-senseselectivity of the photopolymerization.