Temat: PVDF - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Effect of TEOS on the rheological properties of polyvinylidene fluoride and poly(vinylidene fluoride-co-hexafluoropropylene)
Wpływ TEOS na właściwości reologiczne polifluorku winylidenu i poli(fluorku winylidenu-co-heksafluoropropylenu)
Autorzy:: Abid, Monis Bin
Gzara, Lassaad
Moujdin, Iqbal Ahmed
Salam, Mohamed Abdel
Wahab, Roswanira Abdul
Tematy:: TEOS
PVDF
viscosity
lepkość; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Powiązania:: https://bibliotekanauki.pl/articles/59115205.pdf Link otwiera się w nowym oknie
Opis:: The influence of TEOS on the rheological properties of PVDF and poly(vinylidene fluoride-co-hexafluoropropylene) was investigated. The addition of TEOS to low molecular weight PVDF results in pseudoplastic behavior. The exception is PVDF containing 5 wt%. TEOS, which shows dilation behavior. Similar behavior has high molecular weight PVDF with the addition of 2 wt.% TEOS and low molecular weight copolymer with and without TEOS. The influence of temperature on the viscosity and activation energy of the tested PVDF solutions and the influence of TEOS on the average molecular weight were also examined.
Zbadano wpływ TEOS na właściwości reologiczne PVDF oraz poli(fluorku winylidenu-co-heksafluoropropylenu). Dodatek TEOS do PVDF o małej masie cząsteczkowej skutkuje właściwościami pseudoplastycznymi. Wyjątek stanowi PVDF zawierający 5% mas. TEOS, który wykazuje właściwości dylatacyjne. Tak samo zachowuje się PVDF o dużej masie cząsteczkowej z dodatkiem 2% mas. TEOS oraz kopolimer o małej masie cząsteczkowej z dodatkiem i bez dodatku TEOS. Zbadano także wpływ temperatury na lepkość i energię aktywacji badanych roztworów PVDF oraz wpływ TEOS na średnią masę cząsteczkową.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Impact of membrane pore structure on protein detection sensitivity of affinity-based immunoassay
Autorzy:: Ahmad, A. L.
Ideris, N.
Ooi, B.S.
Low, S.C.
Ismail, A.
Tematy:: morphology
PVDF membrane
protein immobilization; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/777927.pdf Link otwiera się w nowym oknie
Opis:: Understanding a membrane’s morphology is important for controlling its final performance during protein immobilization. Porous, symmetric membranes were prepared from a polyvinylidene fluoride/N-methyl-2-pyrrolidinone solution by phase inversion process, to obtain membrane with various microsized pores. The concentration and surface area of aprotein dotted on the membrane surface were measured by staining with Ponceau S dye. The dotted protein was further scanned and analysed to perform quantitative measurements for relative comparison. The intensity of the red protein spot and its surface area varied depending on the membrane pore size, demonstrating the dependence of protein immobilization on this factor. The membrane with the smallest pore size (M3) showed the highest protein spot intensity and surface area when examined at different protein concentrations. An increase in the applied protein volume showed a linearity proportional trend to the total surface area, and an uneven round dot shape was observed at a large applied volume of protein solution.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Enhanced Energetic Performance of Polyvinylidene Fluoride-Coated Zirconium Particle
Autorzy:: Heo, Won Young
Bae, Sung Hwa
Son, Injoon
Tematy:: PVDF
zirconium
coating
energetic behaviors; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2049255.pdf Link otwiera się w nowym oknie
Opis:: In this study, energetic behaviors of polyvinylidene fluoride (PVDF)-coated zirconium (Zr) powders were investigated using thermogravimetric analyzer-differential scanning calorimetry (TGA-DSC). PVDF-coated Zr powder had 1.5 times higher heat flow than ZrO2-passivated Zr powder. PVDF-coated Zr powder had a Zr-F compound formed on its surface by its strong chemical bond. This compound acted as an oxidation-protecting layer, providing an efficient combustion path to inner pure Zr particle while thermal oxidation was progressing at the same time. PVDF coating layers also made thermal reaction start at a lower temperature than ZrO2-passivated Zr powder. It was obtained that the surface PVDF coating layer evaporated at approximately 673 K, but the surface oxide layer fully reacted at approximately 923 K by DSC analysis. Hence, Zr powders showed enhanced energetic properties by the PVDF-coated process.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Nanocomposite Sulfonated PVDF-TiO2 Membranes as a Potential Alternative for Nafion
Autorzy:: Juliandri, Juliandri
Rukiah, Rukiah
Ernawati, E. E.
Handika, R. S.
Nasir, M.
Tematy:: PVDF membrane
conductivity
nanocomposites
titanium oxide; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1165508.pdf Link otwiera się w nowym oknie
Opis:: Fuel cell is an alternative renewable energy source which potentially able to replace a fossil fuel. Nowadays, common fuel cell membrane generally used is Nafion. PVDF polymer is another synthetic polymer which has excellent physical and chemical properties. The purpose of this research is to synthesize an alternative fuel cell membrane, using sulfonated PVDF doped with TiO2 nanoparticles. Sol-gel method was performed to synthesize TiO2 nanoparticles, with TiCl4 as precursor. PVDF membranes with variation of TiO2 composition (0, 1, 1.5, and 2%) were prepared with ultrasonic method. The composite membranes then were sulfonated with concentrated sulfuric acid. The composite membranes were characterized with FTIR for functional group analysis, SEM-EDX for morphology analysis, acid-base titration for degree of sulfonation, weight difference for degree of water uptake, and four point lines for conductivity. FTIR spectra of the sulfonated membrane show the existence of sulfonic group at wavenumber of 601, 1400, and 1454 cm-1. The result of SEM-EDX analysis shows that the nanoparticles of TiO2 were not distributed homogenously. Degree of sulfonation of the PVDF-TiO2 2% composite membrane is 19.54%, and its water uptake is 23.34%. The highest conductivity is about 3.17 × 10-3 S cm-1 for the PVDF-TiO2 2% composite membrane that is very close to Nafion’s conductivity, 6.08 × 10-3 S cm-1.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Synthesis and Characterization of Nanocomposite Sulfonated PVDF Membrane
Autorzy:: Juliandri, Juliandri
Rukiah, Rukiah
Ernawati, E. E.
Silitonga, M. P. R.
Nasir, M.
Tematy:: PVDF membrane
nanocomposites
silicon oxide
titanium oxide; Pokaż więcej
Wydawca:: Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Powiązania:: https://bibliotekanauki.pl/articles/1167197.pdf Link otwiera się w nowym oknie
Opis:: As a commercial fuel cell membrane, Nafion has disadvantages such as low stability at high temperature and low conductivity at low humidity. Sulfonated Polyvinylidene fluoride (PVDF) is known for good mechanical and thermal properties as a membrane. The purpose of this research is to synthesis a nanocomposite PVDF-TiSiO4 membrane as a potential replacement of Nafion. PVDF sulfonation was performed using concentrated sulfuric acid. The nanocomposites TiSiO4 were synthesized from TiCl4 and TEOS. Ultrasonification was used to insert the nanomaterial to the sulfonated membrane. The infrared spectra analysis shows the peak for the Ti-O-Si angel. SEM-EDX analysis shows that the nanocomposite PVDF-TiSiO4 membrane contents titanium oxide. The conductivity analysis shows the increasing of conductivity on addition of nanomaterials.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Pomiar ciśnienia fali uderzeniowej za pomocą polimerowego czujnika piezoelektrycznego
Shockwave pressure measurement with the use of polymer piezoelectric pressure gauge
Autorzy:: Sarzyński, A.
Tematy:: fala uderzeniowa
obróbka laserowa
laserowe umacnianie udarowe
czujnik ciśnienia PVDF
shock wave
laser processing
laser shock processing (LSP)
PVDF pressure gauge; Pokaż więcej
Wydawca:: Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Powiązania:: https://bibliotekanauki.pl/articles/151614.pdf Link otwiera się w nowym oknie
Opis:: W pracy zamieszczono literaturowe informacje dotyczące piezoelektrycznych czujników ciśnienia typu PVDF, pozwalających mierzyć ciśnienie fali uderzeniowej o amplitudzie do 45 GPa z rozdzielczością czasową 5 ns. Zamieszczono formuły wzorcowania czujników. Opisano przykłady wykorzystania czujników w takich dziedzinach jak: kontrola ruchu drogowego, badanie właściwości materiałowych, pomiar ciśnienia fali uderzeniowej. Przedstawiono wyniki własnych pomiarów fal uderzeniowych wzbudzanych przez impuls promieniowania laserowego.
The review of publications on the subject of PVDF piezoelectric pressure gauges is presented in the paper. PVDF gauges allow to measure pressures up to 45 GPa with temporal resolution of about 5 ns. The calibration formulas of pressure gauges are included (fig. 1). Some examples of application of PVDF gauges in such areas like medicine, traffic control, material properties investigation and shockwave are presented. Results of author's measurements of laser induced shockwave are described (fig. 4 - 6). Influence of such parameters as sample thickness and acoustic impedance of layers on pressure profile is shown. The experimental setup will be used for optimization of laser shock processing technology.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Fabrication and Characterization of Photochromic Spirooxazine/Polyvinylidene Fluoride Fiber Membranes via Electrospinning
Wytwarzanie za pomocą elektroprzędzenia i charakterystyka fotochromowych membran światłowodowych z spiroksazyny i fluorku poliwalildanu
Autorzy:: Peng, L.
Guo, R.
Lan, J.
Jiang, S.
Tematy:: PVDF
spirooxazine
electrospinning
photochromic
hydrophobic
spiroksaksyna
elektroprzędzenie
membrany światłowodowe; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Powiązania:: https://bibliotekanauki.pl/articles/946161.pdf Link otwiera się w nowym oknie
Opis:: In this study, photochromic spirooxazine material of N-methyl-3,3-dimethyl-9'-hydroxy-spiro[2H-indole-2-[3H] naphtho [2,1-b] [1,4] oxazine] was synthesised. Spirooxazine/PVDF fiber (SPF) membranes with different contents ofspirooxazine were successfully prepared by electrospinning. The SPF membranes were characterised by FTIR and SEM.The photochromic properties and contact angle of the SPF membranes were evaluated. The results show that the SPF membranes change from colorless to blue whenexposed to UV light, but they revert to their original colour after the UV light disappears. The colour difference and contact angle of the SPF membranes firstly increase and then decrease with a rise in the content of spirooxazine.
W pracy otrzymano fotochromowy materiał spirooksazynowy N-metylo-3,3-dimetylo-9'-hydroksy-spiro [2H-indolo-2 - [3H] nafto [2,1-b] [1,4] oksazyny]. Za pomocą elektroprzędzenia wytworzono membrany z spiroksaksyny i fluorku poliwalildanu PVDF (SPF) o różnej zawartości spiroksaksyny. Błony SPF scharakteryzowano za pomocą FTIR i SEM. Oceniono właściwości fotochromowe i kąt zwilżania błon SPF. Wyniki pokazały, że membrany SPF zmieniają kolor z bezbarwnego na niebieski po ekspozycji na światło UV, ale powracają do swojego pierwotnego koloru po zaniku światła UV. Różnica barwy i kąt zwilżania membran SPF najpierw wzrastają, a następnie zmniejszają się wraz ze wzrostem zawartości spirooksazyny.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Application of Piezofilms for Excitation and Active Damping of Blade Flexural Vibration
Autorzy:: Pešek, L.
Půst, L.
Bula, V.
Cibulka, J.
Tematy:: vibration suppression
parametric antiresonance
active damping
PVDF films; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/177268.pdf Link otwiera się w nowym oknie
Opis:: The steam turbine blades of low pressure stages are endangerd by the high-cyclic fatigue due to the combined loading of dynamic stresses by the steam time-variant pressure and the pre-stress from centrifugal forces. Therefore, the importance of their experimental dynamic analysis in the design stage is critical. For laboratory tests of the blades, the piezo actuators placed on the blades, unlike electromagnets placed in the stationary space, give a possibility to excite the flexural vibration of the blades within the bladed disk by time continuous forces independently of the rotor revolutions. In addition, the piezo actuators can be also used to control the vibrations of the blade. Therefore, several dynamic experiments of the clamped model blade equipped with PVDF films were performed for the force description of the piezo foils and their behavior as actuators of the blade vibration. The numerical beam models were used for numerical analysis of the vibration suppression effects both by additional parametric excitation and by active damping. The optimal phase shift of piezo actuator voltage supply was ascertained both for amplitude amplification and suppression. The results contribute to the knowledge of the actuation and active damping of blade vibration by the piezo elements.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Conductive polymer based nanocomposite membranes for biomedical applications
Autorzy:: Stodolak-Zych, E.
Chmielewska, M.
Jeleń, P.
Tematy:: porous membranes
carbon fillers
polyvinylidene difluoride (PVDF)
conductive
phase inversion; Pokaż więcej
Wydawca:: Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Polskie Towarzystwo Biominerałów
Powiązania:: https://bibliotekanauki.pl/articles/284370.pdf Link otwiera się w nowym oknie
Opis:: The aim of this work was to examine composite membranes obtained by means of phase inversion from a synthetic stable polymer – polyvinylidene difluoride (PVDF). The piezoelectric polymer was modified with 0.5-1wt% addition of commercial carbon fillers: graphite oxide (GO, 1wt%), multiwalled carbon nanotubes (CNT, 1wt%) and functionalized nanotubes (CNT-COOH, 0.5wt%). The membranes were obtained by solidification of nanocomposite solutions in coagulation bath (CH3OH). The obtained series of materials differed in surface porosity (P), electric conductivity (σ) and surface free energy (SFE). It was proved that presence of carbon nanoadditive influenced microstructure of the membranes: the mean size of pores in the membrane rose in the following order: GO→CNT→CNT-COOH. The very same system depicted the influence of the filler on the membrane structure: the increase in membrane crystallinity (λ) and the β phase share (FT Raman). From all the examined nanocomposite systems, the PVDF modified with 0.5wt% CNT-COOH displayed the most advantageous electric properties. These nanocomposite membrane (PVDF/CNT-COOH) could be used as a low-voltage electrodes in biomedical application. Yet, taking into account the other physicochemical, mechanical and structural properties, the membranes modified with 1wt% CNT and 1wt% GO were also interesting.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Deposition of a polymeric porous superhydrophobic thin layer on the surface of poly(vinylidenefluoride) hollow fiber membrane
Autorzy:: Ahmad, A. L.
Mohammed, H. N.
Ooi, B. S.
Leo, C. P.
Tematy:: Superhydrophobic layer
PVDF
Gas-liquid contactor
CO2
porous; Pokaż więcej
Wydawca:: Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Powiązania:: https://bibliotekanauki.pl/articles/778912.pdf Link otwiera się w nowym oknie
Opis:: Porous superhydrophobic layer of low-density polyethylene (LDPE) was created by a simple approach on the Poly(vinylidenefluoride) (PVDF) hollow fiber membranes. Acetone and ethanol mixtures with different volume ratios were used as the non-solvent on the coating surface. A 5:1 (v/v) acetone/ethanol ratio provided a porous surface with a 152° ± 3.2 water contact angle. The high contact angle could reduce membrane wettability for better carbon dioxide capture when the membrane was used as gas-liquid contactor in absorption processes. To assess the effect of the created superhydrophobic layer, the pristine and modified membranes were tested in a CO2 absorption system for ten days. The results revealed that the absorption flux in the modified membrane was higher than that of pristine membrane.
Dostawca treści:: Biblioteka Nauki

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