Blue Phosphorescent Iridium Complexes with Fluorine-free Main Ligands for Efficient Organic Light-emitting Diodes

신화용,정성진,김성현,홍종인 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.8

Two heteroleptic iridium(III) complexes with fluorine-free pyridylpyrimidine main ligands were designed and synthesized for use as blue phosphorescent emitters in organic light-emitting diodes (OLEDs). Complexes 1 and 2 have a molecular formula of Ir(C∧N)2(L∧X), where C∧N = 2-tert-butyl-5-(pyridin-2-yl)pyrimidine (b5ppmH) is the main ligand and L∧X = picolinic acid (pic) and 2-(1H-tetrazol-5-yl)pyridine (ptz) are ancillary ligands. The thermal, photophysical, and electrochemical properties of these complexes were investigated. Even without electron-withdrawing fluorine substituents, the complexes emitted blue light at 463 and 455 nm with moderate quantum efficiencies (ΦPL = 0.54 and 0.43), respectively. Furthermore, the replacement of the pyridine ring with a pyrimidine ring allowed blue emission without fluorine substituents. An organic light-emitting device fabricated using complex 2 as a dopant and 1,3-bis(N-carbazolyl)benzene (mCP) as a host exhibited a maximum external quantum efficiency of 11.5% and color coordinates of (0.17, 0.26) at 100 cd/m2.

REBCO 초전도 박막제조를 위한 Fluorine-free MOD 전구체 용액 개발

김병주,임선원,김호진,홍계원,이희균,Kim, Byeong-Joo,Lim, Sun-Weon,Kim, Ho-Jin,Hong, Gye-Won,Lee, Hee-Gyoun 한국초전도학회 2006 Progress in superconductivity Vol.7 No.2

New precursor solution with dichloroacetic acid (DCA) was developed for fabricating high $J_c$ REBCO film. DCA based-precursor solution was coated on $LaAlO_3$(001) substrate by dip coating method. Processing parameters such as oxygen partial pressure, water vapor, ramping rate and pyrolysis temperature were controlled in order to obtain a good epitaxial film. The film with thickness of 0.5 micrometer was obtained by single coating and no crack was observed at calcined films. Oxygen partial pressure was controlled in the range of $100{\sim}1,000$ ppm and conversion heat treatment was carried out at the temperature range of $705-765^{\circ}C$. A critical transition temperature ($T_c$) of 90 K and a critical transport current density ($J_c$) of $>0.5\;MA/cm^2$ (77 K and self-field) were obtained for the GdBCO film. It is thought that fluorine-free MOD solution using DCA is promising precursor solution for fabricating high quality REBCO films.

Effect of basicity and B₂O₃ on the viscosity and structure of fluorine-free mold flux

Zhang, Lei,Wang, Wanlin,Xie, Senlin,Zhang, Kaixuan,Sohn, Il Elsevier 2017 Journal of non-crystalline solids Vol.460 No.-

<P><B>Abstract</B></P> <P>The effect of basicity (weight ratio of CaO/SiO<SUB>2</SUB>) and B<SUB>2</SUB>O<SUB>3</SUB> on the viscosity and structure of Fluorine-free mold flux for the casting of medium carbon steels was conducted in this article, through the rotating cylinder method combined with the Fourier transform infrared (FTIR) spectroscopy. The results showed that, with the increase of basicity, the viscosity of mold flux was attenuated dramatically, and then kept constant or slight increased in the low temperature region. The reason could be explained as the degree of polymerization (DOP) of the network structure was first reduced significantly with the addition of basicity, and then the further depolymerization is less pronounced with the further increase of basicity. Beside the formation of high melting point substance leads to the slight increase of viscosity. Moreover, it suggested that the viscosity of mold flux is decreased with the addition of B<SUB>2</SUB>O<SUB>3</SUB> content, due to the fact that B<SUB>2</SUB>O<SUB>3</SUB> is a low melting point oxide which could substantially lower the break temperature of mold flux. The result of FTIR indicated B<SUB>2</SUB>O<SUB>3</SUB> acts as network former, and tends to form [BO<SUB>3</SUB>]-trihedral and [BO<SUB>4</SUB>]-tetrahedral structural units, which would connect with each other to form some simple network structure such as diborate or pentaborate. With the addition of B<SUB>2</SUB>O<SUB>3</SUB>, the free oxygen ions (O<SUP>2−</SUP>) would depolymerize the diborate structural unit, and the depolymerized diborate would link again with free [BO<SUB>3</SUB>]-trihedral to form complex pentaborate groups. Moreover, the effect of above addition on the apparent activation energy for viscous flow and break temperature of mold flux also were discussed. The results obtained in this paper provide the detailed study of the structure evolution of Fluorine-free mold flux when B<SUB>2</SUB>O<SUB>3</SUB> is added.</P>

Synthesis and Properties of a Fluorine-free Water Repellent

김일진,장지원,천지원,이동진,이진홍 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.-

Bioorthogonal click chemistry for fluorine-18 labeling protocols under physiologically friendly reaction condition

Elsevier 2015 Journal of fluorine chemistry Vol.174 No.-

<P><B>Abstract</B></P> <P>To expand the applications of positron emission tomography (PET), novel specific radiopharmaceuticals using positron-emitters, such as fluorine-18 (F-18, <I>t</I> <SUB>1/2</SUB> =109.8min), will be needed. Recently, strain-promoted alkyne azide cycloaddition (SPAAC) has been considered as an alternative bioorthogonal conjugation reaction between bioactive molecules and radiolabeled building blocks for the synthesis of novel radiopharmaceuticals. This mini-review provides a rapid overview of the emerging synthetic strategies based on the copper-free SPAAC conjugation reaction under physiologically-friendly reaction conditions for the high-throughput synthesis of <SUP>18</SUP>F-labeled peptide tracers. Furthermore, an efficient mesoporous silica nanoparticles (MSNs) pretargeting for PET imaging were also introduced through the <I>in situ</I> bioorthogonal SPAAC labeling reaction by forming <SUP>18</SUP>F-labeled MSNs at the tumor site in a living specimen.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Developments of novel specific radiopharmaceuticals are necessary for PET study. </LI> <LI> Strain-promoted alkyne azide cycloaddition (SPAAC) does not need any catalysts. </LI> <LI> SPAAC reaction regards as an alternative bioorthogonal ligation for F-18 labeling. </LI> <LI> We report synthetic strategies for the synthesis of <SUP>18</SUP>F-labeled peptides via SPAAC. </LI> <LI> We report MSNs pretargeting for PET imaging via SPAAC labeling in living specimen. </LI> </UL> </P>

불소화 및 초음파 수세가 폴리(에틸렌 테레프탈레이트) 필름의 표면 특성에 미치는 영향

김도영(Do Young Kim),인세진(Se Jin In),이영석(Young Seak Lee) 한국고분자학회 2013 폴리머 Vol.37 No.3

본 연구에서는 고분자 소재 중 한나인 폴리(에텔렌 테레프탈이레이트)(poly(ethylene terephthalate), PET)필름의표면을 천수성으로 개질하기 위하여 기상 불소화 및 초음파 수세를 실시하였다. 표면 처리된 PET 필름의 표면 특성은 접촉각, 표면 자유에어지, 주사전자 현미경(FE-SEM), 원자간력 현미경(AFM), X선 광전자분석법(XPS)을 통하여 분석하였다. 직접 불소화 및 초음파 수세 처리된 PET 필름의 물 접촉각은 10.8。으로 미처리된 PET 에 비하여 85% 감소하였고, 총 표면 자유에너지는 42.24 mNm-1으로 미처리된 PET 에 비하여 650% 증가하였다. 또한 RMS(root mean square) 거칠기는 1.965 nm 로 미처리된 PET 필름에 비하여 348% 증가하였으며, 천수성 관능기인 C-Oh 결합의 농도는 약 3배 가까이 증가하였다. 이는 직접 불소화 및 초음파 수세 처리된 PET 필름 표면에 형성된 천수성 관능기와 공동화 현상에 의한 화학적 식각 반응에서 기인한 것으로 생각된다. 이 결과로부터, 기상 불소화 및 초음파 수세 처리법은 PET 필름 표면을 친수성으로 쉽게 개질할 수 있는 효과적인 방법으로 기대된다. In this study, poly (ethylene terephthalate) (PET) was treated with fluorination and ultrasonic washing treatment for hydrophilic modification of PET film. We measured the change of surface modified PET film surface characteristics using contact angle, surface free energy, FE-SEM, AMF and XP5. After direct fluorination and ultrasonic washing treat-ment, the water contact angle was measured to be 10.81。, 85% reduction compared to the untreated PET film. Total sur-face free energy has been measured to be 42.25mNm-1, 650% increase compared to the untreated PET film. Also RMS roughness has been mcasured to be 1.965nm, 348%increase compared to the untreated PET film. Hydrophilic functional group C-OH bond concentration has increased approximately 3 tomes. These results are attributed to the hydrophilic func-tional group and cavitation due to chemical etching. From this result, it was suggested that the fluorination-ultrasonic washing treatment method could be useful to make PET film surface hydrophilic.

Durable corrosion resistant and hot water repellent superhydrophobic bilayer coating based on fluorine-free chemicals

Binbin Zhang,Mengying Qiao,Guojun Ji,Baorong Hou 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.119 No.-

Due to their unique interface functions, superhydrophobic materials have a wide range of applications. However, the majority of current superhydrophobic surfaces are designed and manufactured using fluorinatedchemical reagents. Moreover, high temperature water droplets with lower surface tension easilypinning to the surface, resulting in interfacial property failures. To overcome these deficiencies, herein wefabricated a superhydrophobic bilayer coating on Q235 carbon steel based on fluorine-free chemicals ofpolydimethylsiloxane (PDMS) and hexadecyltrimethoxysilane modified aluminum oxide nanoparticles(Al2O3@HDTMS). Field-emission scanning electron microscopy (FE-SEM), Energy dispersive spectroscopy(EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Contactangle meter, and Electrochemical impedance spectroscopy (EIS) techniques were utilized to characterizethe constructed superhydrophobic bilayer coating. The results show that the superhydrophobic bilayercoating exhibits non-wetting, anti-fouling and self-cleaning capacities towards various solid and liquidpollutants. The superhydrophobic bilayer coating possesses superior anti-corrosion and weather resistingproperties with |Z|0.01Hz and Rct values increased by more than eight orders of magnitude, withstanding720 h accelerated salt-spray and 50 days outdoor atmospheric corrosion attack. Furthermore, the superhydrophobicbilayer coating features super-repellency towards water droplets in a wide temperaturerange (30 90 C) and accompanied with high mechanical stability against continuous sandpaper abrasionand tape-peeling cycles.

Multi-coated YBa₂Cu₃O<SUB>7-x</SUB> Films Fabricated by a Fluorine-Free Sol-Gel Process

E. A. Cho,G. E. Jang,O. B. Hyun 한국자기학회 2011 Journal of Magnetics Vol.16 No.2

YBa₂C₃O7-x films were fabricated on a SrTiO3 (100) substrate using a trimethylaceate propionic acid (TMAP)-based MOD process by controlling the precursor solution viscosity, firing temperature, and by using various coatings. The viscosity of the precursor solution was controlled by the addition of Xylenes. The films were heat treated with different temperatures from 750 to 800 ℃. c-axis oriented films were obtained. After adding 9 ㎖ of Xylene into the precursor solution, the Tc of the YBCO film, which was coated 2 times and heat treated at 800 ℃, was 86 K and the measured Jc was above 2.5 MA/㎠ at 77 K in a zero-field.

Fluorination of free lithium residues on the surface of lithium nickel cobalt aluminum oxide cathode materials for lithium ion batteries

Kim, H.,Lee, K.,Kim, S.,Kim, Y. Elsevier Ltd 2016 Materials & Design Vol.100 No.-

<P>Lithium nickel cobalt aluminum oxide (LNCA) cathode materials for lithium ion batteries (LIBs) were treated with NH4FHF to convert free Li2CO3 and LiOH, which are natively present on the LNCA surface, into a stable LiF layer. Gas evolution caused by a side-reaction between the reactive free lithium compounds and electrolyte was greatly reduced using this method. The pH of the water dispersion of LNCA was also lower; this indicates that LiOH, which causes rapid polymerization of the polyvinylidene fluoride binder in the slurry for electrode casting, was effectively eliminated. No significant decrease of the electrochemical performance of LNCA was observed with the treatment. Designed as a one-step simple wet process, the developed method is expected to be practically applicable for mass production with suppressed swelling of LIBs and stabilization of the electrode fabrication process. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Gas Transport Properties of Fluorinated Polyimide Membranes by Engineering Free Volume Elements

임남규,박재성,이재기,김효원 한국공업화학회 2023 한국공업화학회 연구논문 초록집 Vol.2023 No.1