Abstract Purpose : In this study, α-Lipoic acid and pyridine were added to hydrogel materials and silicone hydrogel materials, respectively, to manufacture contact lens to evaluate changes in physical properties. Methods : N,N-Dimethylacrylamide (DMA), 2,2'-Azobis (2-methylpropionitrile) (AIBN), an initiator, and Ethylene glycol dimethacrylate (EGDMA), crosslinking agent, were used basic mixing ratio, and hydrogel materials were prepared by thermopolymerization at 100°C for 1 hour based on 2-Hydroxyethyl methacrylate (HEMA). Silicone hydrogel materials were prepared by thermopolymerization at 130°C for 2 hours based on Silicone monomer (SID). The properties of contact lenses were evaluated by adding 0.05% of 3-hydroxypyridine N-oxide and (R)-(+)-α-Lipoic acid by ratio to each material. Results : A lens manufactured by adding alpha lipoic acid to silicone hydrogel materials showed a tendency to increase wettability and decrease refractive index. A lens manufactured by adding pyridine to silicone hydrogel materials showed UV-A blocking ability, and the refractive index tended to increase. In addition, a contact lens manufactured by adding alpha lipoic acid and pyridine together showed antimicrobial properties, reduced surface roughness, and increased wettability and oxygen permeability according to the ratio of alpha lipoic acid addition. Conclusion : It is judged that alpha lipoic acid and pyridine are expected to improve wettability and oxygen permeability of the lens and to be used as contact lens materials with antibacterial properties. Key words : Alpha lipoic acid, Antimicrobial, Oxygen permeability, Pyridine, Wettability

This work using first-principles theory proposed PdN3- doped CNT ( PdN3-CNT) as a potential gas sensor for detection of NO, NO2 and O3 in the air insulated equipment, to evaluate its operation status. Results indicate that the PdN3- CNT behaves chemisorption upon three gas species, with adsorption energy (Ead) of − 2.15, − 1.91 and − 1.96 eV, and charge-transfer (QT) of − 0.141, − 0.325 and − 0.419 e, respectively. The band structure (BS) and density of state (DOS) analysis reveal that the gas adsorptions cause remarkable deformations in the electronic property of the PdN3- CNT, leading to the increase of the bandgap for the gas adsorbed systems and verifying the strong binding force of the bonded atoms from the orbital DOS. Combined with the results by frontier molecular orbital theory, we presume that PdN3- CNT is a promising sensing material to be explored as a resistance-type gas sensor for detection of NOx with higher electrical response upon NO. It is our hope that our theoretical assumption could be further studied and realized in the following experiential research, which would be meaningful to propose novel sensing candidate in the field of electrical engineering to guarantee the safe operation of the air insulation equipment.

Single C-vacancy and pyridine-like N3 defect are usually formed on the single-walled carbon nanotube (SWCNT) and they have unique properties for potential applications. In this paper, we use density functional theory to investigate the discrepancies of such two structures from the geometric and electronic aspects. Our results indicate that the existed single vacancy in the SWCNT can lead to somewhat electron localization because of the lone pair electrons; while the N3 embedded SWCNT ( N3-SWCNT) has stronger chemical reactivity and electron localization than the single vacancy SWCNT (SV-SWCNT) due to the great charge transfer between N3 group and C atom on the tube sidewall. Through the investigation of Ag-doping on the above two nano-structures, we found that the single Ag atom is much more stably adsorbed on the N3- SWCNT sidewall compared with SV-SWCNT, forming higher binding energy and higher electron transfer. Our calculation would shed light on the physicochemical property of SWCNT-based material and thus extend their potential applications in many fields.

목적: 본 연구는 2-fluoro-4-pyridinecarboxylic acid 및 6-fluoropyridine-3-carboxylic acid를 사용하여 친수성 하이드로젤 콘택트렌즈 재질을 중합하고 제조된 친수성 콘택트렌즈의 물리적, 광학적 특성을 분석하여 이들 물질들의 콘택트렌즈 재료로서의 활용도를 알아보았다. 방법: 본 연구는 카르복시산 및 불소로 치환한 피리딘을 2가지 이상 첨가제로 사용하여 친수성 콘택트렌즈의 기본적인 재질인 HEMA(2-hydroxyethyl methacrylate), AA(acrylic acid), MMA(methylme-thacrylate), 개시제인 AIBN(azobisisobutyronitrile), 그리고 교차결합제인 EGDMA(ethylene glycol dimethacrylate)를 사용하여 공중합하였다. 결과: 생성된 고분자의 물리적 특성을 측정한 결과, 굴절률 1.4348-1.4300, 함수율 33.69~35.84%, 가시광선 투과율 89.6~90.8%, 인장강도 0.2292-0.3344kgf 그리고 접촉각의 경우 76.05°~50.95°의 분포를 나타내었다. 또한 황색포도상구균에 대한 항균실험 결과 2-fluoro-4-pyridinecarboxylic acid 및 6- fluoropyridine-3-carboxylic acid를 5% 첨가했을 때 항균효과가 다소 있는 것으로 나타났다. 결 론: 본 실험 결과, 2-fluoro-4-pyridinecarboxylic acid 및 6-fluoropyridine-3-carboxylic acid를 첨가하여 제조된 친수성 콘택트렌즈는 기본적인 콘택트렌즈 물성을 만족하였으며 우수한 습윤성과 항균성 및 자외선 차단 콘택트렌즈로 활용될 수 있을 것으로 판단된다.

A group of new N,N-bis(5-acetylpyridin-2-yl)phenylamine derivatives was synthesized in good yield applying an optimized Buchwald-Hartwig amination protocol. The synthesized compounds showed UV absorption maxima in the range of 320-360 nm, and showed good luminescence at dilute concentrations in the blue region of the spectra (in the range of 480-497 nm). They showed also a bathochromic shift associating the increase in solvent polarity. The synthesized compounds could be investigated for use in OLEDs or as potential monomers for PLEDs.

Pyridine could be successfully removed in the polyurethane(PU) biofilter inoculated with activated sludge treating industrial wastewater. The elimination capacity for pyridine in the PU biofilter was approximately 27 g m⁻³ h⁻¹ at the tested loading range, The pH value of drainage was increased due to the accumulation of ammonia which was one of the metabolites of pyridine, Four pyridine-degrading bacteria were isolated from the PU biofilter, and they were closely related with Rhodococcus pyridinivorans(98~99% similarity). The specific growth rate of the isolate in the medium supplemented with pyridine as a sole carbon and energy source were ranged from 0.038 h⁻¹ to 0.051 h⁻¹.

The mesophase pitch was prepared by adding 1~10 wt% of the borane-pyridine complex (BPC) to decant oil. It was prepared in a reactor held at 450℃ for 2 h in N2 atmosphere. The mesophase pitches were analyzed using thermogravimetric analyzer (TGA), melting point apparatus, X-ray diffraction (XRD) and polarized optical microscope. The coke yield, softening point, toluene insoluble, density and content of anisotropy in the mesophase pitches were increased with BPC contents. The XRD profiles did not show any effect of addition of BPC on the formation of mesophase pitch, while the crystallinity of mesophase pitches was increased when the materials were heat treated with boron compound.

Eu(III) exhibits one electron-transfer reduction at E1/2 = -0.564 V(vs. Ag/AgCl) and the hypersensitive peak at 615 ㎚ corresponding to 5D0→7F2 transition in 0.1 M LiClO4 aqueous solution. Upon the addition of 2,6-pyridine dicarboxylic acid(PDA) to the Eu(III) aqueous soultion, the reduction potential shifts negatively and the PDA, and the Eu(III)-PDA complex emits great fluorescence than free-Eu(III) ion at 615 nm. The results are interpreted in term of the electrochemical and spectrofluorometric studies.