Crystal forms and ferroelectric properties of poly(vinylidene fluoride)/polyamide 11 blends prepared by high-shear processing

2007 ◽  
Vol 45 (19) ◽  
pp. 2707-2714 ◽  
Author(s):  
Yongjin Li ◽  
Hiroshi Shimizu ◽  
Toshiaki Furumichi ◽  
Yoshiyuki Takahashi ◽  
Takeo Furukawa
2008 ◽  
Vol 8 (4) ◽  
pp. 1714-1720 ◽  
Author(s):  
Yongjin Li ◽  
Yuko Iwakura ◽  
Hiroshi Shimizu

Polyamide 11 (PA11)/clay, Poly(vinylidene fluoride) (PVDF)/clay and PVDF/PA11/clay nanocomposites were prepared by melt processing using a high shear extruder. Two types of organoclay with different modified alkyl tails and different polarities were used for PA11 and PVDF nanocomposites. PA11 nanocomposites derived from an organoclay having one alkyl tail show a well-exfoliated morphology but no crystal form transformation, whereas those derived from an organoclay having two alkyl tails give a little worse clay dispersion with the clear α to γ crystal form transition with the addition of the clay. In contrast, the PVDF composites derived from the two organoclays result in a poor dispersion. In addition, PVDF/PA11 blend nanocomposites with a novel morphology have been fabricated using the high-shear extruder. It was found that the clay platelets were selectively dispersed in the PA11 phase with the size of larger than 200 nm, while no clay platelets were located in the PVDF phase and in the PA11 nanodomains with the size of smaller than 200 nm. Moreover, the addition of organoclay shows significant effects on the phase structure of PVDF/PA11 blends.


Author(s):  
Guanchun Rui ◽  
Yanfei Huang ◽  
Xinyue Chen ◽  
Ruipeng Li ◽  
Dingrui Wang ◽  
...  

Oriented amorphous fraction in biaxially oriented poly(vinylidene fluoride) gives it significantly enhanced dielectric and ferroelectric properties.


2001 ◽  
Vol 665 ◽  
Author(s):  
Feng Xia ◽  
H.S. Xu ◽  
Babak Razavi ◽  
Q. M. Zhang

ABSTRACTFerroelectric polymer thin films are attractive for a wide range of applications such as MEMS, IR sensors, and memory devices. We present the results of a recent investigation on the thickness dependence of the ferroelectric properties of poly(vinylidene fluoridetrifluoroethylene) copolymer spin cast films on electroded Si substrate. We show that as the film thickness is reduced, there exist two thickness regions. For films at thickness above 100 nm, the thickness dependence of the ferroelectric properties can be attributed to the interface effect. However, for thinner films, there is a large change in the ferroelectric properties such as the polarization level, the coercive field, and polarization switching speed, which is related to the large drop of the crystallinity in the ultrathin film region (below 100 nm). The results from Xray, dielectric measurement, and AFM all indicate that there is a threshold thickness at about 100 nm below which the crystallinity in the film reduces abruptly.


2018 ◽  
Vol 52 (1) ◽  
pp. 385-394 ◽  
Author(s):  
Jipeng Guan ◽  
Jieqing Shen ◽  
Xingru Chen ◽  
Hengti Wang ◽  
Qin Chen ◽  
...  

2008 ◽  
Vol 1071 ◽  
Author(s):  
Koji Aizawa

AbstractCharacterization of 700-nm-thick poly(vinylidene fluoride/trifluoroethylene) [P(VDF/TrFE)]/TiO2/Al-doped ZnO (AZO) structures on a glass substrate were investigated. In this study, the sputtered TiO2 films as insulator were used for the reduction of leakage current. The leakage current density of the fabricated Pt/P(VDF/TrFE)/AZO and Pt/P(VDF/TrFE)/170-nm-thick TiO2/AZO structures were approximately 8.7 and 3.9 nA/cm2 at the applied voltage of 10 V, respectively. In the polarization vs. voltage characteristics, the fabricated Pt/P(VDF/TrFE)/TiO2/AZO structures showed hysteresis loops caused by ferroelectric polarization. The remnant polarization (2Pr) and coercive voltage (2Vc) measured from a saturated hysteresis loop at the frequency of 50 Hz were approximately 12 μC/cm2 and 105 V, respectively. These results suggest that the insertion of TiO2 film is available for reducing the gate leakage current without changing the ferroelectric properties.


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