• Title/Summary/Keyword: photo-cross-linking agent

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Encapsulation of Nanomaterials within Intermediary Layer Cross-linked Micelles Using a Photo-Cross-linking Agent

  • Kim, Jin-Sook;Youk, Ji-Ho
    • Macromolecular Research
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    • v.17 no.11
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    • pp.926-930
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    • 2009
  • A new method for encapsulating nanomaterials within intermediary layer cross-linked (ILCL) polymeric micelles using a bifunctional photo-cross-linking agent was developed. For ILCL polymeric micelles, an amphiphilic triblock copolymer of poly(ethylene glycol)-b-poly(2-hydroxyethyl methacrylate)-b-poly(methyl methacrylate) (PEG-PHEMA-PMMA) was synthesized via consecutive atom transfer radical polymerization (ATRP), Di(4-hydroxyl benzophenone) dodecanedioate (BPD) was used as a bifunctional photo-cross-linking agent. The PMMA-tethered Au nanoparticles and BPD, or pyrene and BPD were encapsulated in the PEG-PHEMA-PMMA micelles, and their intermediary layers were photo-cross-linked by UV irradiation for 1 h. The HEMA units donated labile hydrogens to the excited-state benzophenone groups in BPD, and they were subsequently cross-linked by BPD through radical-radical combination. The spherical structures of the PEG-PHEMA-PMMA micelles containing the Au nanoparticles or pyrene were unaffected by the photo-cross-linking process.

Effects of the Content of Hydrophilic Crosslinking agents in Acrylate Copolymers on Physical Properties of Lens (아크릴계 공중합체에서 친수성가교제 특성에 따른 렌즈의 물리적 성질 변화)

  • Kim, Ki Sang;Shim, Sang-Yeon
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.1
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    • pp.305-311
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    • 2019
  • The acrylic copolymer was designed and prepared for soft lens with high content. The copolymers were prepared using 2-hydroxyethyl methacrylate(HEMA) as a monomer and ethylene glycol dimethacrylate(EGDMA), glycerol dimethacrylate(GD), or glycerol 1,3-diglycerolate diacrylate (GDD) as a cross linking agent. The water content for high water content lens was 46%, which was higher compared to general purpose of 36%. The contact angle decreased from 38.6 to 34.4, which appears hydrophilic surface. The tensile strength decreased from 0.1 Mpato 0.08, then again to 0.05 as hydrophilic properties of cross linking agents increased. No phase separation was observed in the cross section of lens using scanning electron microscope. The real-time infrared technique was used in photo-polymerization. The initial polymerization rate increased from 0.6 to 0.9, depending on crosslinking agent.

Development of Pore Filled Anion Exchange Membrane Using UV Polymerization Method for Anion Exchange Membrane Fuel Cell Application (음이온교환막 연료전지 응용을 위한 UV 중합법을 이용한 세공 충진 음이온교환막 개발)

  • Ga Jin Kwak;Do Hyeong Kim;Sang Yong Nam
    • Membrane Journal
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    • v.33 no.2
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    • pp.77-86
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    • 2023
  • In this study, pore-filled ion exchange membranes with low membrane resistance and high hydroxide ion conductivity was developed. To improve alkali durability, a porous substrate made of polytetrafluoroethylene was used, and a copolymer was prepared using monomers 2-(dimethyl amino) ethyl methacrylate (DMAEMA) and vinyl benzyl chloride (VBC) for pores. divinyl benzene (DVB) was used as the cross-linker, and ion exchange membranes were prepared for each cross-linking agent content to study the effect of the cross-linker content on DMAEMA-DVB and VBC-DMAEMA-DVB copolymers. As a result, chemical stability is improved by using a PTFE material substrate, and productivity can be increased by enabling fast photo polymerization at a low temperature by using a low-pressure UV lamp. To confirm the physical and chemical stability of the ion exchange membrane required for an anion exchange membrane fuel cell, tensile strength, and alkali resistance tests were conducted. As a result, as the cross-linking degree increased, the tensile strength increased by approximately 40 MPa, and finally, through the silver conductivity and alkali resistance tests, it was confirmed that the alkaline stability increased as the cross-linking agent increased.

Organic-inorganic Hybrid Materials for Spin Coating Hardmask (스핀코팅 하드마스크용 유-무기 하이브리드 소재에 관한 연구)

  • Yu, Je Jeong;Hwang, Seok-Ho;Kim, Sang Bum
    • Applied Chemistry for Engineering
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    • v.22 no.2
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    • pp.230-234
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    • 2011
  • In this work, the primary material for a single layered hardmask which can afford a spin-on process was prepared by the minture of organic and inorganic sources. The preparation of hybrid polymer was attempted by esterification from silanol terminated siloxane compounds and acetonide-2,2-bis(methoxy)propionic acid. The optical, thermal and morphological properties of the test hardmask film was examined in terms of cross-linking agent and additives. In addition, the etch rate of hardmask film and photo resist layer were compared. The hybrid polymer prepared from organic and inorganic materials was found to be useful for hardmask film to form the nano-patterns.