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Thermal and mechanical properties of PVDF/PANI blends
Malmonge, Luiz Francisco;Langiano, Simone do Carmo;Cordeiro, Jo?o Manoel Marques;Mattoso, Luiz Henrique Capparelli;Malmonge, José Antonio;
Materials Research , 2010, DOI: 10.1590/S1516-14392010000400007
Abstract: poly(vinylidene fluoride)/polyaniline blends of different composition were synthesized by chemical polymerization of aniline in a mixture of poly(vinylidene fluoride) and n,n-dimethylformamide and their thermal and mechanical behavior was investigated as a function of the polyaniline doping level and the composition using thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis and tensile tests techniques. the results showed the blend obtained presents a good thermal stability with low weight loss up to 300 oc, assigned to water and solvents evaporation. the glass transition and melting point is not affected by the pani content in the blend, showing that polymers are no miscible. the films produced present a good sustainability; however the presence of the conducting polymer in the blend increases the tensile strength and the young modulus, while diminishes the elongation at break, as compared to pure pvdf.
Medidor de energia para laser pulsado
CAMPOS, Jo?o Sinézio de Carvalho;SANTARINE, Gerson Antonio;
Eclética Química , 1997, DOI: 10.1590/S0100-46701997000100009
Abstract: this work describes the construction of a pyroeletric detector for measurements of laser pulse energy, using the polymer polyvinylidene fluorid (pvdf). the experimental data measured by detector showed a linear response for energy between 0,4 to 6,8 mj/pulse for 8,3 milisecond duration pulse.
Effect of doped and undoped POMA on the morphology and miscibility of blends with Poly(vinylidene fluoride) (PVDF)
Rocha, I.S.;Malmonge, L.F.;Mattoso, L.H.C.;Gregorio Jr., R.;
Materials Research , 1999, DOI: 10.1590/S1516-14391999000200004
Abstract: the effect of the addition of small amounts of doped and undoped poly(o-methoxyaniline) (poma) on the morphology of melt crystallized pvdf was investigated by means of polarized light optical microscopy. undoped poma (poma-eb) inhibits nucleation and growth of non ringed spherulites, partially formed by the polar gphase, whereas poma doped with toluene sulfonic acid (poma-tsa) favors this process. moreover, the doping of poma increases the miscibility between the components of the pvdf/poma blends, resulting in more homogeneous films. a possible cause of this miscibility increase and for the favoring of the polar gphase, is the higher polarity of the poma chains as a result of the doping.
Effect of doped and undoped POMA on the morphology and miscibility of blends with Poly(vinylidene fluoride) (PVDF)
Rocha I.S.,Malmonge L.F.,Mattoso L.H.C.,Gregorio Jr. R.
Materials Research , 1999,
Abstract: The effect of the addition of small amounts of doped and undoped poly(o-methoxyaniline) (POMA) on the morphology of melt crystallized PVDF was investigated by means of polarized light optical microscopy. Undoped POMA (POMA-EB) inhibits nucleation and growth of non ringed spherulites, partially formed by the polar gphase, whereas POMA doped with toluene sulfonic acid (POMA-TSA) favors this process. Moreover, the doping of POMA increases the miscibility between the components of the PVDF/POMA blends, resulting in more homogeneous films. A possible cause of this miscibility increase and for the favoring of the polar gphase, is the higher polarity of the POMA chains as a result of the doping.
PVDF Piezoelectric Film Based Force Measuring System
Yanshen Wang,Yuxian Gai,Long Kang,Jian Qu
Research Journal of Applied Sciences, Engineering and Technology , 2012,
Abstract: In this study, a force measuring system based on PVDF piezoelectric sensor was designed. Firstly, piezoelectric equation of PVDF was simplified for the following analysis. Secondly, circuits of charge amplifier and signal filter were designed. Noise induced by electronic components and 50 Hz power frequency were restrained heavily by 5th-order Butterworth low-pass filter and 50 Hz double T trap filter. Finally, a measuring circuit board was made based on the above research, so as to construct measuring system and measure experiment. Measuring experiment proved the effective of this system.
Effect of Solution Concentration on the Electrospray/Electrospinning Transition and on the Crystalline Phase of PVDF  [PDF]
Lígia Maria Manzine Costa, Rosário Elida Suman Bretas, Rinaldo Gregorio
Materials Sciences and Applications (MSA) , 2010, DOI: 10.4236/msa.2010.14036
Abstract: A study was conducted regarding the effect of concentration of poly (vinylidene fluoride) (PVDF)/N,N-dimethylformamide (DMF) and PVDF/DMF/acetone solutions on the transition between electrospray and electrospinning and on the formation of the ? and ? crystalline phases of PVDF. The crystalline phases present in the samples, crystallinity and morphology were determined by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM), respectively. Low concentration solutions resulted in films consisting of small droplets (electrospray) containing predominantly the ? phase. High concentration solutions resulted in a non-woven mesh of nano-to-micron diameter fibers (electrospinning) containing exclusively the ? phase. These results showed that, the formation of this phase in the electrospinning is related mainly to the solvent evaporation rate, and not to drawing experienced by the polymer during the process. Solvent type affected the amount of crystalline phase present, the boundary concentration between the two processes and the average diameter of fibers. Meshes processed by electrospinning display a degree of crystallinity higher than the films obtained by electrospray.
Short Circuit Thermally Stimulated Discharge Current Measurement on PMMA:PEMA:PVDF Ternary Blends  [PDF]
A. K Gupta, A. Tiwari, R Bajpai, J. M Keller
Materials Sciences and Applications (MSA) , 2011, DOI: 10.4236/msa.2011.28141
Abstract: The attainment of a better understanding and improvement of electrical properties of ternary blend is a task of particular scientific and economic importance. Ternary films of Poly (methylmethacrylate), Poly (ethlymathacrylate) and poly (vinlylidenefluoride) were prepared using solution cast technique. Thereafter, to study the hetro charges, homo-charges and interfacial charge formation in ternary system, the short circuit thermally stimulated discharge current (SC-TSDC) measurements were carried out on bilaterally metallized electrets. The ternary blend samples taken for the present investigations are hetrogeneous system involving three polymers differing in their conduction behaviour and dielectric property. Thus, unequal ohmic conduction currents arriving at the interface are expected to result in accumulation of charges at the interface or the Maxwell-Wagner effect. Clearly the Maxwell Wagner effect is expected to contribute discernibly to the observed TSDC’s of the ternary blends. The PMMA: PEMA: PVDF:: 100:100:50 blend exhibits highest tendency while 100:50:100 the least, towards the anomalous current flow. Moreover, the conductivity of 100: 100: 50 is found to be more and, therefore, a large amount of homocharge is injected leading to anomalous current.
AFM Image of Collagen on Induced Aligned Fluoropolymer Substrates
M.D. Rozana,M.J. Reece,L. Famiza,A.N. Arshad
Journal of Applied Sciences , 2012,
Abstract: Reconstituted collagen film formed from lyophilized collagen in acetic acid and deposited on glass slide substrate was found to be randomly orientated. In this study PVDF and its copolymer (PVDF-TrFE) were used as a template for depositing collagen, a type of protein abundantly found in human body. The objective of this study was to develop the nucleation and growth of the aligned PVDF and PVDF-TrFE crystals. Collagen films formed, showed strong affinity to these fluoropolymers. The PVDF/PTFE fibres initiated growth of collagen films present in coiled collagen twisted structures around the PVDF and PVDF-TrFE fibres. The thickness of the collagen on the PTFE film obtained from AFM approximately 15 nm. Upon deposition of collagen on PVDF-TrFE/PTFE films, the thickness increased to 40-110 nm. The collagen was observed to orientate in the direction of PVDF-TrFE/PTFE. The collagen film formed on 72-28 PVDF-TrFE/PTFE film template was observed to be relatively less disorder and can be used in biomedical application. The dielectric properties of the collagen may be investigated for the application in electro-mechanical applications.
倒相法制备多孔PVDF薄膜的条件探索
任旭梅,白莹,黄学杰
电化学 , 2001,
Abstract: 本文运用倒相法制备了适用于锂离子二次电池用的PVDF多孔隔膜材料,通过改变聚合物与溶剂、非溶剂之间的配比;控制温度、溶剂挥发速率、在非溶剂浴中的时间等条件,得到了一系列多孔PVDF薄膜,研究了涂敷溶液中溶剂与非溶剂的浓度对PVDF多孔膜的结构和性质的影响,得出了规律性的结论
PVDF压电薄膜传感器在便携式宫缩监测仪器中的应用
Application of PVDF Piezoelectric Film Sensor in Uterine Contraction Pressure Monitoring
 [PDF]

应红华, 干红, 梅秀峰, 张晓红
Instrumentation and Equipments (IaE) , 2015, DOI: 10.12677/IaE.2015.31002
Abstract:
针对于传统压力传感器在宫缩监测中普遍存在的测量精度低、舒适度差等问题,在分析PVDF薄膜压电效应基础上,探讨了用于便携式宫缩压力监测仪器的PVDF压电薄膜传感器制作工艺,设计了宫缩压力信号放大和滤波预处理电路。在医院临床对PVDF压电薄膜传感器进行性能测试,结果表明:此传感器能够精准地感测到孕妇的子宫收缩变化,降低对孕妇正常活动造成的影响,符合当前医疗设备向便携化、移动化、可穿戴发展的趋势。
For the low accuracy and poor comfort of traditional pressure sensors in uterine contraction pressure monitoring, a PVDF piezoelectric thin film sensor was fabricated. In this paper, PVDF film piezoelectric effect, fabrication process of sensors and design of signal preprocess were discussed. The performance testing in hospital for this sensor was made and the experimental results showed that this sensor can detect uterine contraction pressure accurately and reduce the impact on the normal activities of pregnant women, complying with the trend that current medical instrumenta-tion is becoming portable, mobile and wearable.
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