• Title/Summary/Keyword: Cross linker

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Effect of Antimicrobial Activity of the Glutaraldehyde Cross-linked Glucosamine (글루코사민-글루타르알데히드 가교결합체의 항균 효과)

  • Lee, Choon Geun;Hwang, You Jin;Park, Jae Kweon
    • Journal of Marine Bioscience and Biotechnology
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    • v.6 no.2
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    • pp.53-61
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    • 2014
  • This study was investigated the antimicrobial activity of glutaraldehyde cross-linked glucosamine. Glutaraldehyde was used as a cross-linker which specifically combines an amine-group of molecules. To optimize the mixing ratio of glutaraldehyde and glucosamine, mixing ratio was set up 1:1, 2:1, 3:1 and 0.5:1 in molarity, respectively. The optimum mixing ratio of glucosamine and glutaraldehyde was found to be 3:1 using thin layer chromatography based on the production of complex. Glucosamine-glutaraldehyde cross-linked complex (Ggcc) revealed significant antimicrobial activity toward PWG than F1, both microbial strains were isolated from porcine semen as antibiotics resistance bacteria (ARB). These results clearly demonstrate that Ggcc has potential bactericidal activity toward ARB in porcine semen.

Preparation of Highly Cross-Linked, Monodisperse Poly(methyl methacrylate) Microspheres by Dispersion Polymerization; Part II. Semi-continuous Processes

  • Lee, Ki-Chang;Lee, Sang-Yun
    • Macromolecular Research
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    • v.16 no.4
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    • pp.293-302
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    • 2008
  • In our previous publication, the problem of particle deformation and coagulation at the nucleation stage in the presence of cross-linker was intensely studied by seeded batch dispersion polymerization of methyl methacrylate (MMA). In the present work, highly cross-linked, monodisperse PMMA particles were prepared under various reaction conditions by seeded semi-continuous process. Monodisperse, $6.5{\mu}m$-diameter PMMA particles containing up to 8 wt% of DVB or EGDMA were successfully made by seeded semi-continuous process and multi-semi-continuous addition process, respectively. Therefore, this study shows that seeded semi-continuous process is more effective and efficient to prepare highly cross-linked, monodisperse particles than non-seeded and seeded batch processes.

Preparation of Highly Cross-linked, Monodisperse Poly(methyl methacrylate) Microspheres by Dispersion Polymerization; Part I. Batch Processes

  • Lee, Ki-Chang;Lee, Sang-Yun
    • Macromolecular Research
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    • v.15 no.3
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    • pp.244-255
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    • 2007
  • Nucleation is the most sensitive stage in the preparation of highly cross-linked, monodisperse microspheres by dispersion polymerization, since the addition of a small amount of cross-linker results in particle deformation and coagulation. To overcome these problems, $5\;{\mu}m$ poly(methyl methacrylate) seed particles prepared by dispersion polymerization were used in the preparation of mono disperse, cross-linked PMMA particles containing up to 7 wt% divinylbenzene by seeded batch dispersion polymerization. Spherical particles with a narrow size distribution containing up to 8 wt% of EGDMA were prepared by seeded multi-batch dispersion polymerization processes. These particles were identified by scanning electron microscopy and DSC.

Enhancement of Glucose Oxidation Reaction in Enzyme Biofuel Cell Utilizing Anthracene Dicarboxyl acid Cross-linker (Anthracene dicarboxyl acid 가교제를 활용한 효소연료전지의 산화극의 포도당 산화반응 향상)

  • Hyun, Kyuhwan;Ji, Jungyeon;Kwon, Yongchai
    • Korean Chemical Engineering Research
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    • v.57 no.1
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    • pp.1-4
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    • 2019
  • In this study, an anthracene cross-linker is introduced to enhance the catalytic activity of glucose oxidase (GOx) based catalysts and to increase the amount of enzyme loading. The crosslinked GOx is bonded with the CNT/PEI support using the electrostatic interaction (AC[CNT/PEI/GOx]). Electrochemical evaluations are done to evaluate the performance of this catalyst and the performance of CNT/PEI/GOx catalyst is also measured as a control. According to the measurements, it is confirmed that the amount of loaded GOx increases, while $K_m$ value calculated by Lineweaver-Burk plot shows that AC[CNT/PEI/GOx] ($K_m$ : 0.73 mM) is superior to CNT/PEI/GOx ($K_m$ : 1.71 mM) without cross-linking reaction. Based on these effects, it is demonstrated that the maximum power density of the enzymatic biofuel cell using AC[CNT/PEI/GOx] increases from $21.2{\mu}W/cm^2$ to $57.4{\mu}W/cm^2$.

The Implementation of C Cross-Compiler for ES-C2340 DSP2 by Using the GNU Compiler (GNU 컴파일러를 이용한 ES-C2340 DSP2용 C 교차 컴파일러의 개발)

  • Lee, Si-Yeong;Gwon, Yuk-Chun;Yu, Ha-Yeong;Han, Gi-Cheon;Kim, Seung-Ho
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.1
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    • pp.255-269
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    • 1997
  • In this paper, we describe the implementation of C cross-compiler for the ES-C2340 DSP2 processor by using the GNU compiler. For the rapid and efficient developing of the compiler and other parts like the processor-dependent back -end which is implemented newly to build the compiler. This approach has several advantages. First, as we use GNU compiler's well-proved excellent optimization method and multi-language support capability, we can improve he efficiency and generality of the compiler. Second, as we concentrate on the high-level language as logic approving tool in processor developing process. And to support the cross-compiler, we also implement a text-level pre-linker.

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Synthesis and Characterization of Hybrid Nanocomposites of Pd Nanoparticles Containing POSS(Pd-POSS) and Poly(acrylic acid) via Ionic Interactions (실세스키옥세인을 포함한 팔라듐 나노입자와 폴리아크릴산과의 이온결합에 의한 나노복합체 제조 및 특성평가)

  • Jeon, Jong-Hwan;Lim, Jung-Hyurk;Chujo, Yoshiki;Kim, Kyung-Min
    • Polymer(Korea)
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    • v.33 no.6
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    • pp.615-619
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    • 2009
  • Pd-POSS nanoparticles were produced from the reaction of palladium (II) acetate and octa(3-aminopropyl)octasilsesquioxane octahydrochloride (POSS-${NH_3}^+$) in methanol at room temperature. Pd-POSS nanoparticles with a mean diameter of 60-80 nm were the highly ordered spherical aggregates. In contrast, Pd nanoparticles with a size of 4.0 nm were obtained when POSS-${NH_3}^+$ was not introduced. Pd-POSS/PAA nanocomposites of Pd-POSS nanoparticles and poly(acrylic acid) (PAA) were fabricated by utilizing ionic interactions between positively charged Pd-POSS nanoparticles and negatively charged carboxylate groups of PAA. PAA was used as a cross-linker for the preparation of hybrid nanocomposites with the controlled organized structures of Pd-POSS nanoparticles. That is, the self-organization of Pd-POSS nanoparticles was formed into the shape of continuous lines by using PAA as a cross-linker. The composition, structure, surface morphology, and thermal stability of the Pd-POSS/PAA nanocomposites were studied by FE-SEM, AFM, TEM, FT-IR, and TGA.

Incremental and Retargetable Linker for Embedded System (내장형 시스템을 위한 점진적이고 목표 재설정 가능한 링커)

  • Wu, Deok-Kyun;Han, Kyung-Sook;Pyo, Chang-Woo;Kim, Heung-Nam
    • Journal of KIISE:Computing Practices and Letters
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    • v.7 no.2
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    • pp.183-192
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    • 2001
  • In a development environment for embedded system with a connection between host and target system, the linker of host system links the cross-compiled object file and modules of target system and downloads the linked object file to the target system. In this research, we separate this linker into the module dependent on object file format and the module independent on object file format. The dependent module gets the linking information independent on file format from the object file, and the independent module actually does the linking process with this linking information_ This separation can improve the portability of development environment for a target system_ Also, our linker does the incremental remote linking that applies relocation not only to the obj ect file to be loaded but also to target's modules to have been loaded_ This incremental remote linking can reduce a linking time than linking by the united modules because of linking by module. The result of measuring linking time for SPEC95 integer benchmarks shows an average of reduction rates of 64.90%. Also, incremental remote linking can improve the comfortability of users who develop programs because users do not consider a downloading order of linking object files. Currently, we developed this linker in the embedded application development environment ESTO [1] to be prepared for a commercial product.

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InP Quantum Dot-Organosilicon Nanocomposites

  • Dung, Mai Xuan;Mohapatra, Priyaranjan;Choi, Jin-Kyu;Kim, Jin-Hyeok;Jeong, So-Hee;Jeong, Hyun-Dam
    • Bulletin of the Korean Chemical Society
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    • v.33 no.5
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    • pp.1491-1504
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    • 2012
  • InP quantum dot (QD)-organosilicon nanocomposites were synthesized and their photoluminescence quenching was mainly investigated because of their applicability to white LEDs (light emitting diodes). The as-synthesized InP QDs are capped with myristic acid (MA), which are incompatible with typical silicone encapsulants. We have introduced a new ligand, 3-aminopropyldimethylsilane (APDMS), which enables embedding the QDs into vinyl-functionalized silicones through direct chemical bonding. The exchange of ligand from MA to APDMS does not significantly affect the UV absorbance of the InP QDs, but quenches the PL to about 10% of its original value with the relative increase in surface related emission intensities, which is explained by stronger coordination of the APDMS ligands to the surface indium atoms. InP QD-organosilicon nanocomposites were synthesized by connecting the QDs using a short cross-linker such as 1,4-divinyltetramethylsilylethane (DVMSE) by the hydrosilylation reaction. The formation and changes in the optical properties of the InP QD-organosilicon nanocomposite were monitored by ultraviolet visible (UV-vis) absorbance and steady state photoluminescence (PL) spectroscopies. As the hydrosilylation reaction proceeds, the QD-organosilicon nanocomposite is formed and grows in size, causing an increase in the UV-vis absorbance due to the scattering effect. At the same time, the PL spectrum is red-shifted and, very interestingly, the PL is quenched gradually. Three PL quenching mechanisms are regarded as strong candidates for the PL quenching of the QD nanocomposites, namely the scattering effect, F$\ddot{o}$rster resonance energy transfer (FRET) and cross-linker tension preventing the QD's surface relaxation.

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.

A New Alternative Hole-transporting Layer to PEDOT:PSS for Realizing Highly Efficient All Solution-processable PLEDs

  • Kang, Beom-Goo;Kang, Hong-Kyu;Lee, Kwang-Hee;Lee, Chang-Lyoul;Lee, Jae-Suk
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.362-363
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    • 2012
  • A new cross-linkable polymer, cross-linked d-PBAB, which has the triphenylamine as the hole transporting moiety and ethynyl group as the thermal cross-linker is firstly synthesized by the combination of anionic polymerization and deprotection process. The thermal cross-linking reaction was performed at $240^{\circ}C$ for 50 min and cross-linked d-PBAB layer showed smooth surface and is not soluble at organic solvent under spin-coating of emitting layer (EML). The solution-processed PLED which was fabricated with cross-linked d-PBAB as HTL showed approximately two times higher Lmax and four times higher LEmax than those obtained from PLED with PEDOT:PSS as the HTL. These result is ascribed to better ability of cross-linked d-PBAB to block electrons and to prevent exciton-quenching than those of PEDOT : PSS at the EML interface. This results strongly suggested that cross-linked d-PBAB can be a promising material to replace conventional PEDOT : PSS. It can be suspected that PLEDwith cross-linked d-PBAB would show longer lifetime compared with that of PLED with PEDOT : PSS, and thus further studies are under investigation.

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