A STUDY ON THERMO-OPTIC EFFECT OF β POLY(VINYLIDENE FLUORIDE) THIN FILMS PREPARED BY SOLUTION CASTING METHOD

2008 ◽  
Vol 15 (01n02) ◽  
pp. 175-181 ◽  
Author(s):  
YINGXUE XI ◽  
HUIQING FAN ◽  
WEIGUO LIU ◽  
CHEN YANG ◽  
XIAOLING NIU
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Infrared Imaging ◽  
Vinylidene Fluoride ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Long Wavelength ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
Solution Casting Method

The Poly(vinylidene) fluoride (PVDF) thin films with a high content of β-phase were prepared by controlling heat-treatment temperature using casting from the poled solvents. The crystallite microstructure of thin films was depicted by the techniques of X-ray diffraction and FTIR. The results showed that heat treatment was favorable for inducing the β- and γ-phase formation of PVDF. The β phase films were obtained with heat treatment at temperatures ranging from 60°C to 120°C and annealing at 120°C after casting from DMF. The thermo-optical effect of β phase PVDF films was investigated using a spectroscopic ellipsometer. At temperatures ranging from 20°C to 100°C, the refractive index of PVDF was negatively correlated with the temperature between 350 and 1500 nm. The value of the t.o. coefficient of PVDF films was calculated at all temperatures. The maximum value of the t.o. coefficient was about 3.3 × 10-4/°C at the ascending stage of temperature and 3.0 × 10-4/°C at the descending stage of temperature. Therefore, it is possible to use the thermo-optic effect of the β phase PVDF for long wavelength infrared imaging.

scholarly journals Structural and Optical Properties of CuInS2Thin Films Prepared by Magnetron Sputtering and Sulfurization Heat Treatment

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Rongfeng Guan ◽  
Xiaoxue Wang ◽  
Qian Sun
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Magnetron Sputtering ◽  
Treatment Temperature ◽  
Gas Pressure ◽  
X Ray Diffraction ◽  
Raman Spectrometry ◽  
Optimization Of Process Parameters ◽  
Sputtering Power ◽  
Good Crystallinity

CuInS2thin films were prepared by sulfurization of Cu-In precursor films through magnetron sputtering and the resulting films characterized using X-ray diffraction, Raman spectrometry, and UV-Vis spectrophotometry. The results demonstrate that a sputtering power of 80–120 W is more suitable for sputtered Cu-In precursor films and can be used to obtain CuInS2films with good crystallinity through vulcanization heat treatment. The sputtering gas pressure and sulfurization temperature were shown to impact on the film quality due to improper processes during the CuInS2phase. Some of the CuIn11S17and CuS2impurities were observed in the composition of the prepared CuInS2thin films. Optimization of process parameters obtained from the experimental data was determined as a sputtering power of 80~120 W, a sputtering gas pressure of 0.6–0.8 Pa, a heat treatment temperature of 450~470°C, and a holding time of 2~3 hours. The optical band gap obtained for CuInS2thin films is between 1.48 and 1.5 eV.

Enhancement of β phase crystallization and dielectric behavior of kaolinite/halloysite modified poly(vinylidene fluoride) thin films

2014 ◽  
Vol 99 ◽  
pp. 149-159 ◽  
Author(s):  
Pradip Thakur ◽  
Arpan Kool ◽  
Biswajoy Bagchi ◽  
Sukhen Das ◽  
Papiya Nandy
Keyword(s):  
Thin Films ◽  
Vinylidene Fluoride ◽  
Dielectric Behavior ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

The role of cerium(iii)/yttrium(iii) nitrate hexahydrate salts on electroactive β phase nucleation and dielectric properties of poly(vinylidene fluoride) thin films

RSC Advances ◽  
2015 ◽  
Vol 5 (36) ◽  
pp. 28487-28496 ◽  
Author(s):  
Pradip Thakur ◽  
Arpan Kool ◽  
Biswajoy Bagchi ◽  
Nur Amin Hoque ◽  
Sukhen Das ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Nitrate Hexahydrate ◽  
Yttrium Nitrate ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
Phase Nucleation ◽  
Yttrium Nitrate Hexahydrate

Electroactive β phase nucleation in cerium/yttrium nitrate hexahydrate salt modified PVDF thin filmsviaformation of hydrogen bonds.

scholarly journals Influence of molecular weight on dielectric properties and piezoelectric constant of poly(vinylidene fluoride) membranes obtained by electrospinning

Polimery ◽  
2021 ◽  
Vol 66 (10) ◽  
pp. 532
Author(s):  
Aminatul Sobirah Zahari ◽  
Muhammad Hafiz Mazwir ◽  
Izan Izwan Misnon
Keyword(s):  
Molecular Weight ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Piezoelectric Constant ◽  
Phase Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

A significant influence of the molecular weight on the dielectric properties and piezoelectric constant of poly(vinylidene fluoride) (PVDF) membranes obtained by electrospinning was demonstrated. Electrochemical impedance spectroscopy and d33 meter were used to evaluate dielectric properties and piezoelectric constant respectively. The presence of the β-phase was determined by Fourier transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD). The membranes with the lowest molecular weight (180,000 g/mol) possessed the best dielectric properties. They also had the highest piezoelectric constant (21 pC/N) and dielectric constant (2.9 at 50 Hz) as well as the highest β-phase content (80.25%).

Immobilized ionic liquid induced electroactive β-phase in poly(vinylidene fluoride) thin films

Polymer ◽  
2019 ◽  
Vol 181 ◽  
pp. 121784 ◽  
Author(s):  
Shumin Yang ◽  
Fang Wang ◽  
Xiaohui Li ◽  
Yangjiang Wu ◽  
Tongxin Chang ◽  
...  
Keyword(s):  
Thin Films ◽  
Ionic Liquid ◽  
Vinylidene Fluoride ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

Improvement of electroactive β phase nucleation and dielectric properties of WO3·H2O nanoparticle loaded poly(vinylidene fluoride) thin films

RSC Advances ◽  
2015 ◽  
Vol 5 (77) ◽  
pp. 62819-62827 ◽  
Author(s):  
Pradip Thakur ◽  
Arpan Kool ◽  
Biswajoy Bagchi ◽  
Nur Amin Hoque ◽  
Sukhen Das ◽  
...  
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Nucleation Mechanism ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
Phase Nucleation

Electroactive β phase nucleation mechanism and promising dielectric properties of WO3·H2O nanoparticle loaded PVDF thin films.

Stretching Induced Crystalline-Phase Transition in Energy-Conversion Poly(Vinylidene Fluoride) (PVDF) Films

2014 ◽  
Vol 1070-1072 ◽  
pp. 589-593
Author(s):  
Fei Peng Wang ◽  
Zheng Yong Huang ◽  
Jian Li
Keyword(s):  
Phase Transition ◽  
Crystalline Phase ◽  
High Speed ◽  
Vinylidene Fluoride ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Poly Vinylidene Fluoride ◽  
Crystalline Phase Transition

Commercial poly (vinylidene fluoride) (PVDF) films are uniaxially stretched with varying rates at 110 °C in order to endow PVDF piezo-and pyroelectric by crystalline-phase transition from α to β during the stretching. The crystalline phases are determined by infrared spectroscopy. The β-phase content and its fraction in films increase as a result of stretching with high rates. In addition, higher stretching rates yield a slight increase of γ phase. The crystallite size is evaluated by means of X-ray diffraction. It is found that the β-phase crystallites become smaller with fast stretching, whereas the α-phase crystallites are cracked and disappear at high-speed stretching of 2.5 /min.

Effect of in situ synthesized Fe2O3and Co3O4nanoparticles on electroactive β phase crystallization and dielectric properties of poly(vinylidene fluoride) thin films

2015 ◽  
Vol 17 (2) ◽  
pp. 1368-1378 ◽  
Author(s):  
Pradip Thakur ◽  
Arpan Kool ◽  
Biswajoy Bagchi ◽  
Sukhen Das ◽  
Papiya Nandy
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Dielectric Constants ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

In situsynthesis of Fe2O3–Co3O4nanoparticles stabilized electroactive PVDF thin films with colossal dielectric constants.

Improving the thermal stability, electroactive β phase crystallization and dielectric constant of NiO nanoparticle/C–NiO nanocomposite embedded flexible poly(vinylidene fluoride) thin films

RSC Advances ◽  
2016 ◽  
Vol 6 (31) ◽  
pp. 26288-26299 ◽  
Author(s):  
Pradip Thakur ◽  
Arpan Kool ◽  
Nur Amin Hoque ◽  
Biswajoy Bagchi ◽  
Swagata Roy ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Dielectric Constant ◽  
Vinylidene Fluoride ◽  
Β Phase ◽  
Poly Vinylidene Fluoride ◽  
Phase Nucleation ◽  
Nio Nps ◽  
High Dielectric

Increasing β phase nucleation and formation of microcapacitors in flexible high dielectric NiO NPs/C–NiO NCs modified PVDF films.

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