• Journal of Oral Medicine and Pain
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• v.23 no.4
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• pp.343-352
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• 1998

This experiment was performed to investigate effects of zinc containing solution on the major normal flora Staphylococccus aureus, Streptococus mutans and Candida albicans and to observe the variation according to anionic change and concentration difference. Zinc chloride, zinc iodide and zinc acetate solution were added to werially diluted broth culture so that each final concentration might be 0.25%, 0.5%. 1%. After that, 100ul of each aliquot was spreaded on each selective media plate( Mannitol Salts Agar plate for Staphylococcus aureus, Mitis Salivarius Agar plate for Streptococcus mutans and Sabouraud Destrose Agar plate for Candida albicans). The % killing was calculated bu CFU count after incubation under the appropriate condition. 1. zinc iodide, zinc chloride, and zinc acetate solutions showed inhibitory effects on Staphylococcus aureus, Streptococcus mutans and Candida albicans. 2. The inhibitory effects on Staphylococcus aureus were ranked in order of ainc iodide, zinc chloride and zinc actate. 3. The inhibitory effects on Streptococcus mutans were ranked in orfer of zinc iodide, zinc chloride and zinc acetate. 4. the inhibitory effects on Candida albicans showed no difference among zinc iodide, zinc chloride and zinc acetate. 5. The inhibitory effects of zinc chloride and zinc acetate on Staphylococcus aureus and Streptococcus mutnas showed increasing pattern as the concentration increase. But the inhibitory effects of zinc iodide on Staphylococcus aureus and Streptococcus mutans showed no apparent difference according to concentrations and it was the case with the inhibitory effects of zinc iodide, zinc chloride and zinc acetate on Candida albicans.

• Proceedings of the Korean Fiber Society Conference
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• 2000.04a
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• pp.13-16
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• 2000

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.223-226
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• 2001

비닐에테르류의 비닐단량체는 ZnI$_2$ 존재하에서 HI와 같은 프로톤 산에 의해 양이온 리빙중합이 가능함이 보고된 바 있는데 이 때 프로톤산은 비닐에테르 단량체와 반응하여 adduct를 생성하고, ZnI$_2$는 adduct의 양이온중합 활성화제로 작용하는 것으로 알려져 있다. (중략)

• Fibers and Polymers
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• v.2 no.1
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• pp.131-134
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• 2001

Living cationic polymerization behaviors of isobutyl vinyl ehters (IBVE), initiated by iodomethyl methyl ether (IMME)/zinc iodide ($Znl_2$) have been investigated. The polymerization was carried out at 0, -15, and $-30^{\circ}C$ in toluene. It was found that the rate of polymerization increased as the IMME concentration increased and decreased as temperature decreased. 100% conversion was always achieved without exception. Furthermore, the number-average molecular weight ($M_{n}$) of polymers increased in direct proportion to monomer conversion. The molecular weights of polymers were in good agreement with the theoretical values, calculated on the basis that one polymer chain was formed by one IMME molecule and the values of polydispersity index are always less than 1.2, revealing the living nature. The living nature was also confirmed by synthesis of poly(IBVE-b-TBVE) by subsequent monomer addition of t-butyl vinyl ether (TBVE).

• Korean Journal of Materials Research
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• v.27 no.10
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• pp.530-533
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• 2017

ZnO micro/nanocrystals with different morphologies were synthesized by thermal evaporation of various zinc source materials in an air atmosphere. Zinc acetate, zinc carbonate and zinc iodide were used as the source materials. No catalysts or substrates were used in the synthesis of the ZnO crystals. The scanning electron microscope(SEM) image showed that the morphology of ZnO crystals was strongly dependent on the source materials, which suggests that source material is one of the key factors in controlling the morphology of the obtained ZnO crystals. Tetrapods, nanogranular shaped crystals, spherical particles and crayon-shaped crystals were obtained using different source materials. The X-ray diffraction(XRD) pattern revealed that the all the ZnO crystals had hexagonal wurtzite crystalline structures. An ultraviolet emission was observed in the cathodoluminescence spectrum of the ZnO crystals prepared via thermal evaporation of Zn powder. However, a strong green emission centered at around 500 nm was observed in the cathodoluminescence spectra of the ZnO crystals prepared using zinc salts as the source materials.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.91-91
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• 2003

Major factors including solvent and reaction temperature in the cationic polymerization of isobutyl vinyl ether (IBVE), photoinduced in the presence of diphenyliodonium iodide (DPII) zinc iodide in toluene/diethyl ether mixed solvent has been investigated. It was found that the living nature of the propagating species and the tacticity of the resulting polymer is significantly dependent on these factors. The addition of diethyl ether (DEE) results in not only the loss of the cationic living nature but also decrease in the isotactic content.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.1-2
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• 2003

Some new synthetic routes for the preparation of poly (isobutyl vinyl ether) (P(IBVE)) having a controllable molar mass with narrow distribution via catalytic or photoinduced living cationic polymerization and their conversion to corresponding PVA have been developed. It was found that the combination of iodomethyl methyl ether (IMME)-zinc iodide is effective in the initiation of the catalytic and the various combinations of diphenyliodonium halides, well known photocationic initiators (DPIX) with zinc halides (ZnX$_2$) are also useful in photoinduced living cationic polymerization of isobutyl vinyl ether (IBVE). Polymerization both in the catalytic and photoinduced systems precede until the full consumption of the monomer and the rate of polymerization increases as the concentration of the catalyst or photoinitiator. The number average molar mass of the resulting polymer is proportional with % conversion, which is determined by the ratio of monomer consumed and the initial values of the catalyst or initiator. The living nature was also confirmed by subsequent monomer addition technique.

• Journal of Auto-vehicle Safety Association
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• v.13 no.2
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• pp.30-34
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• 2021

Electrical failures and reliability problems of electronic components by ionic migration between adjacent device terminals have become an issue in automotive electronics. Especially unlike galvanic corrosion, ionic migration is occurred at high temperature and high humidity under applied electric field condition. Until now, although extensive studies of the ionic migrations dealing with PCBs, electrodes, and solders were reported, there is no study on the effect of insulation polymers and metallic fillers for ionic migration. In this research, therefore, ionic migration induced by the types and contents of polymers and metallic fillers, and variety conditions of temperature, humidity, and applied voltage was studied in detail. Ester and amide types of liquid crystal polymer (LCP) and poly (phthalamide) (PPA) were used as base polymers, respectively and compounded with the metallic fillers of Copper iodide (CuI), Zinc stearate (Zn-st), or Calcium stearate (Ca-st) in various compositions. The compounding polymers were fabricated in IPC-B-24 of SIR test coupon according to ISO 9455-17 with Cu electrodes for ionic migration test. While there is no change in LCP-based samples, ionic migration in PPA compounding sample with a high water absorption property was accelerated in the presence of 0.25 wt% or above of CuI at the environmental conditions of 85℃, 85% RH and 48V. The dendritic short-circuit growth of Cu caused by ionic migration between the electrodes on the surface of compounded polymers was systematically observed and analyzed by using optical microscopy and SEM (EDX).

• Corrosion Science and Technology
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• v.6 no.4
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• pp.198-205
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• 2007

The initial stages of electrochemical oxidative CuI film formation on Cu(111), as studied by means of Cyclic Voltammetry (CV), in-situ Scanning Tunneling Microscopy (STM) and ex-situ Synchrotron X-ray Photoemission Spectroscopy (SXPS), indicate a significant acceleration of copper oxidation in the presence of iodide anions in the electrolyte. A surface confined supersaturation with mobile CuI monomers first leads to the formation of a 2D-CuI film via nucleation and growth of a Cu/I-bilayer on-top of a pre-adsorbed iodide monolayer. Structurally, this 2D-CuI film is closely related to the (111) plane of crystalline CuI (zinc blende type). Interestingly, this film causes no significant passivation of the copper surface. In an advanced stage of copper dissolution a transition from the 2D- to a 3D-CuI growth mode can be observed.

• Fibers and Polymers
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• v.5 no.4
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• pp.253-258
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• 2004

Living nature of photoinduced cationic polymerization of isobutyl vinyl ether (IBVE) in the presence of various combinations of diphenyliodonium halide (DPIX), a photocationic initiator and zinc halide $(ZnX_2)$ in methylene chloride has been investigated. Attainment of $100\%$ conversion and a linear relationship between $\%$conversion and number average molar mass of the resulting polymer, strongly suggests the living nature of this system. Livingness of the polymerization system was observed irrespective to the type of halide anion of the initiator and zinc salts unless the reaction temperature is not higher than $-30^{\circ}C$. The rate of polymerization decreases in the order of iodide > bromide > chloride when halide salt of DPIX and $ZnX_2$ are used. It is postulated that the cationic initiation is started by the insertion of weakly basic monomer in to the activated C-X terminal of the monomer adduct which is a reaction product of monomer and HX, a photolytic product of DPIX, formed in situ during the photo-irradiation process. It was concluded that polymerization is initiated by the insertion of weakly basic monomer into activated C- X terminal of monomer adduct due to the pulling action of$ZnX_2$, which successively producing a new polarized C-X terminal for the propagation in cationic nature. This led us to a conclusion that the living nature of this cationic polymerization is ascribable to the polarized C-X growing terminal, which is stable enough to depress the processes of chain transfer or termination process.