• Title, Summary, Keyword: trifluoroethylene (TrFE)

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Dehydrofluorination of Vinylidene Fluoride- Trifluoroethylene Copolymer by Phase Transfer Catalysis (Vinylidene Fluoride-Trifluoroethylene 공중합체의 상전이촉매작용에 의한 탈불화수소화)

  • Jo, Jae-Hwan;Song, Ha-Yul;Guk, Yun-Hwan
    • Textile Science and Engineering
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    • v.32 no.1
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    • pp.57-63
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    • 1995
  • Films of vinylidene fluoride - trifluoroethylene (VDF-TrFE ) copolymer were dehydrofluorinated in aqueous sodium hydroxide solutions by phase transfer catalysis(PTC). Conjugated C=C double bonds in the polymer back-bone were bonds in the dehydrofluorination of VDF-TrFE copolymer. The color of film became brown and finally black with rigid double bonds during the PTC reaction. It was found from UV/VIS spectroscopic measurements that the length of conjugated double bonds of dehydrofluorinated VDF-TrFE copolymer was longer than that of dehydrofluorinated poly(vinylidene fluoride) . It was ascribed to the reaction activity due to the difference of solubility parameter between the sample and reaction solution. Thermal behavior by DSC analysis showed that the dehydrofluorination occurred at least in the crystal surfaces as well as in the amorphous chains.

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Basic Study on P(VDF-TrFE) Smart Sensor for Monitoring Composite Structure Behaviors (복합재료구조물 거동 관찰을 위한 P(VDF-TrFE) 스마트센서의 기초연구)

  • Bae, Ji-Hun;Chang, Seung-Hwan
    • Composites Research
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    • v.28 no.3
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    • pp.75-80
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    • 2015
  • Poly(vinylidene fluoride-trifluoroethylene; P(VDF-TrFE)) is one of the most promising electroactive polymers with numerous application potentials in many fields of industry. Because of its good electro-mechanical properties P(VDF-TrFE) has been used for a number of sensors and actuators and also can be used for monitoring composite structure behaviors as a sensor. Three different ways (Electrical poling, annealing-cooling, and pressing) to enhance ${\beta}$-phase of P(VDF-TrFE) film were carried out. A microscopic analysis was conducted using X-ray diffraction to investigate the effect of such treatments on piezoelectric properties of P(VDF-TrFE) film. From the results, poling, annealing-cooling, and pressing were all effective to enhance ${\beta}$ crystallinity of P(VDF-TrFE) film and the maximum increase rate was 62.80% from 45.29% of the control group.

Fabrication and Properties of $VF_2$-TrFE/Si(100) Structure by using Spin Coating Method (Spin Coating 법을 이용한 $VF_2$-TrFE/Si(100) 구조의 제작 및 특성)

  • Lee, Woo-Seok;Jeong, Sang-Hyun;Kwak, No-Won;Kim, Ga-Ram;Yun, Hyeong-Sun;Kim, Kwang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.115-116
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    • 2008
  • The ferroelectric vinylidene fluoride-trifluoroethylene ($VF_2$-TrFE) and $Al_2O_3$ passivation layer for the Metal/Insulator/Ferroelectric/Semiconductor (MIFS) structure were deposited using spin coating and remote plasma atomic layer deposition (RPALD), respectively. A 2.5 ~ 3 wt % diluted solution of purified vinylidene fluoride-trifluoroethylene ($VF_2$: TrFE=70:30) in a DMF solution were prepared and deposited on silicon wafer at a optimized spin speed. After annealing in a vacuum ambient at 150 ~ $200^{\circ}C$ for 60 min, upper insulator layer were deposited at temperature ranging from 100 ~ $150^{\circ}C$ by RPALD. We described electrical and structural properties of MIFS fabricated by spin coating and RPALD methods.

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Curie Temperature Transition According to Microstructure of Polymer Chain in Poly(VDF/TrFE/CTFE) Terpolymer (Poly(VDF/TrFE/CTFE) 3성분계 고분자의 배열구조에 따른 상전이 온도의 변화)

  • Kim, Eun-Kyoung;Lee, Sang-Goo;Ha, Jong-Wook;Park, In-Jun;Lee, Soo-Bok;Park, Cheol-Min;Kim, Young-Ho
    • Polymer(Korea)
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    • v.31 no.4
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    • pp.343-348
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    • 2007
  • In this study, terpolymer of vinylidene fluoride (VDF), trifluoroethylene (TrFE), and chlorotrifluoroethylene (CTFE) were prepared by suspension polymerization using di-tertiary-butyl peroxide (DTBP) as an initiator. The structural characteristics including microstructure and chain conformation of the polymers have been carefully elucidated as a function of the chemical composition using NMR, FT-IR. The intensity of absorption bands of the $\beta$-phase gradually decreases and the $\gamma$-phase increases with the increment of CTFE mol%. The analysis results of DSC shows that the Curie phase transition temperature ($T_c$) of the terpolymer gradually shifts to ambient temperature and trace becomes smaller and broader with the increment of CTFE mol%. Also, activation energies of the samples were calculated by Freeman-Carroll method.

Effects of Plasticizer on the Piezoelectricity of PVDF and P(VDF-TrFE) Films (가소제가 Polyvinylidenefluoride와 Poly(Vinylidenefluoride-Trifluoroethylene)의 압전성에 미치는 영향)

  • Kim, Sang-Yong;Yu, Jong-Hun;Jo, Jae-Hwan
    • Textile Science and Engineering
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    • v.25 no.3
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    • pp.54-61
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    • 1988
  • The effects of plasticizer of on the dynamic mechanical and piezoelectric properties of PVDF and P (VDF-TrFE) films were investigated and their measurements were compared with each other. The addition of plasticizer (tricresyl phosphate) lowered the glass transition temperature of both PVDF and P (VDF-TrEF) films and decreased their moduli. The plasticizer did not affect the crystallinities of PVDF and annealed P(VDF-TrFE), but lowered the crystallinity of unannealed P(VDF-TrFE) significantly. Piezoelectric stress constants (e31) of PVDF and annealed P(VDF-TrFE) increased with the increase in plasticizer content while e31 of unannealed P(VDF-TrFE) decreased because the contribution of the crystallinity decrease was larger than that of plasticizer which made dipole reorientation easier.

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Feasibility Check of Textile Sensor Made of P(VDF-TrFE) for Structural Health Monitoring of Composite Structures (복합재료 구조물의 건전성 모니터링을 위한 P(VDF-TrFE) 직물센서의 가능성 평가)

  • Bae, Ji-Hun;Chang, Seung-Hwan
    • Composites Research
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    • v.30 no.2
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    • pp.126-131
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    • 2017
  • For structural health monitoring of a complex shaped structure a new sensor that can compensate for the drawbacks of the current sensors such as brittleness is needed and the sensor should be highly flexible and durable. In this study a textile sensor made of polyvinylidene fluoride trifluoroethylene (PVDF-TrFE) which is a type of electroactive polymer was fabricated. And the textile sensors were applied to a complex shaped structure (an egg-box panel made of carbon/epoxy composite) for checking their feasibility of structural health monitoring. To correlate the collapse response with failure mechanisms of the structure the multiply-interrupted compressive test was carried out. During the test, the textile sensors succeeded to prove their applicability for damage detection (crack initiation) by generating electric voltages (0.05 V-0.25 V) in the real time.

Fabrications and Properties of VF2-TrFE Films for Nonvolatile Memory Application (비휘발성 메모리 응용을 위한 VF2-TrFE 박막의 제작 및 특성)

  • Jeong, Sang-Hyun;Byun, Jung-Hyun;Kim, Hyun-Jun;Kim, Ji-Hun;Kim, Kwang-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.388-388
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    • 2010
  • In this study, Ferroelectric vinylidene fluoride-trifluoroethylene (VF2-TrFE) copolymer films were directly deposited on degenerated Si (n+, $0.002\;{\Omega}{\cdot}cm$) using by spin coating method. A 1~5 wt% diluted solution of purified vinylidene fluoride-trifluoroethylene (VF2:TrFE = 70:30) in a dimethylformamide (DMF) solvent were prepared and deposited on silicon wafers at a spin rate of 2000 ~ 4000 rpm for 2 ~ 30 seconds. After annealing in a vacuum ambient at 100 ~ $200^{\circ}C$ for 60 min, upper aluminum electrodes were deposited by vacuum evaporation for electrical measurement. X-ray diffraction results showed that the VF2-TrFE films on Si substrates had $\beta$-phase of copolymer structures. The capacitance on highly doped Si wafer showed hysteresis behavior like a butterfly shape and this result indicates clearly that the copolymer films have ferroelectric properties. The typical measured remnant polarization ($P_r$) and coercive filed ($E_c$) values were about $5.7\;{\mu}C/cm^2$ and 710 kV/em, respectively, in an applied electric field of ${\pm}$ 1.5 MV/em. The gate leakage current densities measured at room temperature was less than $7{\times}10^{-7}\; A/cm^2$ under a field of 1 MV/cm.

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Experimental Evidence for the Existence of a New Transition of a VDF and TrFE Copolymer (P(VDF/TrFE)의 새로운 전이에 대한 실험적 증거)

  • 김갑진;이종순;조항원
    • Proceedings of the Korean Fiber Society Conference
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    • pp.105-109
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    • 2002
  • vinylidene fluoride(VDF)와 trifluoroethylene(TrFE)의 공중합체 인 P(VDF/TrFE)는 전기활성을 갖는 강유전성 결정이므로 압전성 및 초전성 재료로 PVDF와 더불어 널리 사용되고 있다. 그러나 P(VDF/TrFE)는 어떤 온도 이상에서는 all-trans conformation을 하는 강유전 결정상이 전기적으로 불활성으로 되면서 PVDP의 $\alpha$-결정의 사슬배좌(trans-gauche)와 유사한 상유전 결정상으로 전이하는 상승 Curie 전이 온도 (T$^{\uparrow}$ $_{c}$ )가 존재하기 때문에 P(VDF/TrFF)의 압전재료로서의 적용온도 범위가 넓지 못하다는 단점이 있다. (중략)

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Measurements of the Second Harmonic Coefficients of the Ferroelectric Polymer P(VDP-TrFE)(72/28 mole%) at 1064 and 532 nm Wavelength (강유전성 고분자 P(VDF-TrFE)(72/28 mole%)의 파장 1064 및 532 nm에 대한 2차 비선형 광학 계수 측정)

  • 정창수;임종선;박광서;김도석;이범구
    • Proceedings of the Optical Society of Korea Conference
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    • pp.232-233
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    • 2001
  • 2차 비선형광학 물질이 높은 응용성을 갖기 위해서는 큰 2차 비선형광학 계수뿐만 아니라 넓은 파장 영역에 걸친 투명성을 가지고 있어야 한다. vinylidene fluoride(VDF)와 trifluoroethylene(TrFE)가 공중합된 f(VDf-TrFE) 공중합체는 이러한 조건을 갖추고 있는 강유전성 물질이다. 우리는 몰비율이 72:28인 P(VDF-TrFE)을 ITO기판위에 casting하고 corona 극화한 뒤, 두 개의 입력 파장(1064nm, 532nm)에 대한 2차 조화파 발생 실험을 실시하고 Herman과 Hayden의 마커무의 식을 이용하여 2차 비선형 광학 계수를 측정하였다. (중략)

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Structural Properties of P(VDF-TrFE) LB Films (P(VDF-TrFE) LB박막의 구조특성)

  • Kwak, Eun-Hwi;Lee, Jin-Ho;Jung, Chi-Sup
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.8
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    • pp.698-703
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    • 2009
  • We report the studies on the structrural properties of Langmuir Blodgett (LB) films fabricated from the copolymer of vinylidenefluoride (VDF) with trifluoroethylene(TrFE). The formation of nanomesas induced by thermal annealing at $135\;^{\circ}C$ for 1 hour was investigated with the atomic force microscope (AFM) and the X-ray diffractometer (XRD). From the result of surface morphology change in 30 monolayer LB film, we find that the annealing treatment on the P(VDF-TrFE) LB film result in the plastic deformation of crystalline polymer. The ${\beta}$ phase crytalline structure in annealed LB film was clearly confirmed from the XRD peak at $19.7^{\circ}$.