• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.714-717
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• 2007

In this study, a novel actuator was developed by employing the newly-synthesized ionic networking membrane (INM) of poly (styrene-alt-maleic anhydride) (PSMAn)-incorporated poly (vinylidene fluoride) (PVDF). Based on the same original membrane, various samples of INM actuator were prepared through different reduction times with the electroless-plating technique. The as-prepared INM actuators were tested in terms of surface resistance, platinum morphology, resonance frequency, tip displacement, current and blocked force, and their performance was compared to that of the widely-used traditional Nafion actuator. Scanning electron microscope (SEM) and transmission electron microscopy (TEM) revealed that much smaller and more uniform platinum particles were formed on the surfaces of the INM actuators as well as within their polymer matrix. Although excellent harmonic response was observed for the newly-developed INM actuators, this was found to be sensitive to the applied reduction times during the fabrication. The mechanical displacement of the INM actuator fabricated after optimum reduction times was much larger than that of its Nafion counterpart of comparable thickness under the stimulus of constant and alternating current voltage.

• Macromolecular Research
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• 제14권6호
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• pp.596-602
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• 2006

The effect of high-temperature spinning and poly(vinyl pyrrolidone) (PVP) additive on poly(vinylidene fluoride) (PVDF) hollow fiber membranes was investigated using differential scanning calorimetry, X-ray diffraction measurement, and scanning electron microscopy, together with the corresponding microfiltration performances such as water flux, rejection rate, and elongational strength. Using high-temperature spinning, porous hollow fiber membranes with particulate morphology were prepared through PVDF crystallization. The particulate structure of the membranes was further modified by the addition of miscible PVP with PVDF. Due to these effects, the rejection rate and strength of the fibers were increased at the expense of reduced water flux and mean pore size, which indicates that high-temperature spinning and PVP addition are vary effective to control the morphology of PVDF hollow fiber membranes for microfiltration.

• 멤브레인
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• 제17권3호
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• pp.233-243
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• 2007

본 연구에서는 충전용 이차전지의 분리막으로 쓰이는 다공성 막을 기존의 분리막 재료보다 뛰어난 물성을 나타내는 PVdF(poly(vinylidene fluoride))를 사용하여 상전이 방법으로 제조하였다. 용매인 DMF(N,N-dimethylformamide)에 PVdF를 단일상으로 녹인 후 깨끗한 유리판에 캐스팅하여 막을 얻었다. 얻어진 분리막에서 가장 높은 공극률은 78.6%로 얻어졌다. UTM(universal testing machine)을 이용하여 측정된 분리막의 인장강도는 PVdF 20 wt%에서 5.16 MPa의 값을 나타내었다. 시차주사현미경(scanning electron microscopy, SEM)을 이용하여 분리막의 단면 관찰을 통해 다공성을 확인하였다.

• 한국막학회:학술대회논문집
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• 한국막학회 2005년도 추계 총회 및 학술발표회
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• pp.192-195
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• 2005

• 멤브레인
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• 제18권3호
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• pp.206-213
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• 2008

폴리비닐리덴풀루오라이드(Poly vinylidene fluoride, PVDF) 막을 고분자(Surface Modifying Macromolecules, SMM) 첨가제를 사용하여 표면 개질 하였다. 표면 개질된 PVDF 막의 제조는 0에서부터 2 wt%까지 SMM의 다양한 농도로 제조되었으며, 사용된 SMM으로써는 Zonyl BA-L을 이용하였다. 제조된 막을 이용하여 주사 전자 현미경법(SEM)과 접촉각 측정(Contact angle)을 하였고, 투과증발(Pervaporation)공정을 이용하여 물-에탄올 계의 분리실험을 통해 특성 평가를 하였다. 그 결과 SEM image를 통하여 SMM이 PVDF막 표면에 층을 형성하였음을 알 수 있었고, 접촉각은 기존의 PVDF 막 보다 SMM을 2 wt% 첨가하였을 때 $8^{\circ}$ 증가한 것으로 보아 소수성이 증가한 것을 알 수 있었다. 또한 물-에탄올 계에 대한 투과증발 실험은 다양한 조업온도별(50, 60, $70^{\circ}C$)로 수행하였으며, Zonyl의 함량이 PVDF 대비 1, 2 wt% 함유된 막을 사용하였으며 원액의 조성은 무게비로 물 10, 20, 50, 100%에 대하여 조사하였다. 물 : 에탄을 = 10 : 90 조성, 조업온도 $50^{\circ}C$에서 선택도 287과 투과도 5.3 $g/m^2hr$를 PVDF/2 wt% Zonyl BA-L 막이 보여주었다.

• 멤브레인
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• 제23권4호
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• pp.312-318
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• 2013

Poly vinylidene fluoride (PVDF) 중공사막을 polyethylenimine (PEI)와 p-xylylene dichloride (XDC)를 이용해 친수화 시킨 후 poly(vinyl alcohol) (PVA)과 가교제인 poly(acrylic acid-co-maleic acid) (PAM) 혼합용액을 코팅하여 막을 제조하였다. 중공사막 표면의 코팅여부는 scanning electron microscope (SEM)을 통해 관찰하였으며, 막의 특성평가를 위해 물/에탄올 혼합액에 대한 투과증발 실험을 수행하였다. 공급액 조성은 90 wt% 에탄올 수용액을 사용하였으며, 가교제 농도, 공급액과 반응온도 변화에 따른 투과도 및 선택도를 측정하였다. 투과도는 반응온도 $100^{\circ}C$, PAM 농도 3 wt%, 공급액온도 $70^{\circ}C$에서 $1,480g/m^2hr$, 그리고 선택도는 반응온도 $100^{\circ}C$, PAM 농도 15 wt%, 공급액온도 $25^{\circ}C$에서 ${\alpha}_{W/E}=82$의 결과를 얻을 수 있었다.

• 멤브레인
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• 제27권2호
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• pp.189-198
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• 2017

본 연구는 수처리 분리막에 제조하기 위하여 열유도 상분리법(thermally induced phase separation, TIPS)을 이용하였고, 기계적 물성과 내화학성이 우수한 폴리플루오르화비닐리덴(poly(vinylidene fluoride)(PVDF)) 고분자와 실리카를 이용하여 특성평가를 진행하였다. 특성평가에 사용된 희석제는 dioctyl phthalate (DOP), dibutyl phthalate (DBP)를 사용하였으며, PVDF와 실리카의 비율에 따른 분리막 제조 조건을 알아보기 위하여 결정화 온도, 흐림점, SEM 이미지 등을 관찰하였다. 실리카의 함량이 증가할수록 결정화 온도와 흐림점이 증가하였음을 확인하였고, 상평형도 작도를 통하여 분리막 제조 조건을 확인하였다.

• 전기화학회지
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• 제9권1호
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• pp.29-33
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• 2006

A new porous separator based on poly(vinyl chloride) (PVC)/poly(vinylidene fluoride-co-hexafluoro-propylene) (P(VdF-co-HFP)/poly(methyl methacrylate) (PMMA) was prepared by a phase inversion method. To enhance mechanical property, the membrane was stretched uniaxially at high temperature. Tensile strength and ionic conductivity were measured for various draw ratios. The tensile strength and ionic conductivity were increased with increasing draw ratio. The tensile strength of the separator reached 52MPa after stretching to draw ratio of 5, and the ionic conductivity of the separator was increased from $1.9Xs10^{-4}S/cm\;to\;4.6X10^{-4}S/cm\;at\;25^{\circ}C$. The stretched separator immersed in liquid electrolyte was electrochemically stable up to 4.7 V. The cell based on the stretched separator was maintained at about 99% of the initial discharge capacity after 10th cycle operation at 0.2C rate.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.126.2-126.2
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• 2010

The "grafting from" technology to prepare the well-defined microphase-separated structure of polymer using atom transfer radical polymerization (ATRP) will be introduced in this presentation. Various amphiphilic comb copolymers were synthesized through this approach using poly (vinylidene fluoride) (PVDF), poly (vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-co-CTFE) and poly(vinyl chloride) (PVC) as a macroinitiator. Hydrophilic side chains such as poly (styrene sulfonic acid) (PSSA) or poly (sulfopropyl methacrylate) (PSPMA) were grafted from the mains chains using direct initiation of the chlorine atoms. The structure of mass transport channels has been controlled and fixed by crosslinking the hydrophobic domains, which also provides the greater mechanical properties of membranes. Successful synthesis and microphase-separated structure of the polymer were confirmed by $^1H$ NMR, FT-IR spectroscopy and TEM. The grafted/crosslinked membranes exhibited good mechanical properties (400 MPa of Young's modulus) and high thermal stability (up to $300^{\circ}C$), as determined by a universal testing machine (UTM) and TGA, respectively.

• Membrane and Water Treatment
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• 제9권4호
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• pp.221-231
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• 2018

A new procedure to produce poly(vinylidene fluoride)/boron nitride hybrid membrane is presented for application in membrane distillation (MD) process. The influence of hexagonal boron nitride (h-BN) incorporation on the performance of the polymeric membranes is studied through the present investigation. For this aim, h-BN nanopowders were successfully synthesized using the simple chemical vapor deposition (CVD) route and subsequent solvent treatments. The resulting h-BN nanosheets were blended with poly(vinylidene fluoride) (PVDF) solution. Then, the prepared composite solution was subjected to phase inversion process to obtain PVDF/h-BN hybrid membranes. Various examinations such as scanning electron microscopy (SEM), wettability, permeation flux, mechanical strength and liquid entry pressure (LEP) measurements are performed to evaluate the prepared membrane. Moreover, Air gap membrane distillation (AGMD) experiments were carried out to investigate the salt rejection performance and the durability of membranes. The results show that our hybrid PVDF/h-BN membrane presents higher water permeation flux (${\sim}18kg/m^2h$) compared to pristine PVDF membrane. In addition, the experimental data confirms that the prepared nanocomposite membrane is hydrophobic (water contact angle: ${\sim}103^{\circ}$), has a porous skin layer (>85%), as well competitive fouling resistance and operational durability. Furthermore, the total salt rejection efficiency was obtained for PVDF/h-BN membrane. The results prove that the novel PVDF/h-BN membrane can be easily synthesized and applied in MD process for salt rejection purposes.