2005 12th International Symposium on Electrets最新文献

{"title":"Polymer light emitting devices with Langmuir Blodgett (LB) films of a polyfluorene derivative","authors":"C. A. Olivati, M. Ferreira, A. M. Machado, L. Akcelrud, O. Oliveira jr, J. Giacometti","doi":"10.1109/ISE.2005.1612418","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612418","url":null,"abstract":"Polyfluorenes are promising materials for the emitting layer of polymer light emitting devices (PLEDs) with blue emission. In this work, we report on PLEDs fabricated with Langmuir-Blodgett (LB) films of a polyfluorene derivative, namely poly(9,9-di-hexylfluorenediyl vinylene-alt-1,4-phenylenevinylene) (PDHF-PV). Y-type LB films were transferred onto ITO substrates at a surface pressure of 35 mN m/sup -1/ and with dipping speed of 3 mm min/sup -1/1. A thin aluminum layer was evaporated on top of the LB film, thus yielding a sandwich structure (ITO/PDHF-PV(LB)/Al). Current-voltage (I vs V) measurements indicate that the device displays a classical behavior of a rectifying diode. The threshold value is approximately 5 V, and the onset for visible light emission occurs at ca. 10 V. From the a.c. electrical responses we infer that the active layer has a typical behavior of PLEDs where the real component of ac conductivity obeys a power-law with the frequency. Cole-Cole plots (Im(Z) vs. Re(Z)) for the device exhibit a series of semicircles, the diameter of which decreases with increasing forward bias. This PLED structure is modeled by a parallel resistance and capacitance combination, representing the dominant mechanisms of charge transport and polarization in the organic layer, in series with a resistance representing the ITO contact. Overall, the results presented here demonstrate the feasibility of LEDs made with LB films of PDHF-PV.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"169 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128849778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ferroelectric switching and dielectric response of P(VDF-TrFE)/PMMA blends","authors":"R. L. Moreira, L. O. Faria, C. Wisniewski, J. Giacometti","doi":"10.1109/ISE.2005.1612349","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612349","url":null,"abstract":"The ferroelectric and the dielectric behaviors of binary blends formed by an equimolar Poly(vinylidene fluoride-trifluoroethylene) copolymer [P(VDF-TrFE)] and Poly(methyl methacrylate) [PMMA] were investigated, for several PMMA compositions. For 40 wt% or more PMMA contents, the blends are completely amorphous. Below this value, they crystallize in the usual Cm2m polar structure of P(VDF-TrFE). The ferroelectric switching characteristics and the dielectric response of the blends demonstrate the formation of dynamically stable ferroelectric domains. Moreover, the blended films are highly transparent in the optical region. Therefore, thin films of these binary blends are good candidates as host materials for nonlinear optical applications.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124795224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of fast electron irradiation on the dielectric and pyroelectric response of radially-oriented PVDF film","authors":"B. Hilczer, H. Smogór, J. Kutek, J. Goslar","doi":"10.1109/ISE.2005.1612333","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612333","url":null,"abstract":"Radiation-induced functionalization of ferroelectric P(VDF/TrFE) copolymers was found to be effective in production of polymer relaxors attractive for applications. We studied radiation-induced changes in the dielectric relaxation and pyroelectric response of radially oriented PVDF film irradiated with electrons of energies 0.5-1.5 MeV. Radiation damage to the samples was characterized by ESR and IR spectroscopy. An increase in activation energy of segmental motion of the polymer and a downward shift of the freezing temperature of segmental motion and the Curie temperature, induced by electron irradiation, was related to a damage in all-trans conformation of the polymer chain and formation of polar regions.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115296044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High dielectric constant polymer nano-composites actuator materials","authors":"C. Huang, K. Ren, S. Zhang, F. Xia, Q.M. Zhang","doi":"10.1109/ISE.2005.1612326","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612326","url":null,"abstract":"Charge transport plays very important role in many electronic materials. Recently, making use of the delocalized electrons in conjugated /spl pi/-electrons in organics, several all-polymer composites have been developed which exhibited dielectric constant higher than 1,000 and high electromechanical responses with much reduced electric field (for example, 14% strain induced under 25 MV/m with an elastic energy density of 0.85 J/cm/sup 3/). This talk will discuss these developments, including the significant enhancement of the dielectric and electromechanical responses in these composites when the inclusion size is reduced from sub-microns to nanometers. The interfacial polarization exchange effect and local field fluctuations in these nano-composites play very important role in enhancing the dielectric and electromechanical responses.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123682131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Layer-by-layer films of poly(o-ethoxyaniline) and chitosan-potly(methacrylic acid) nanoparticles","authors":"C. E. Borato, R. Goy, F. L. Leite, C. L. de Vasconcelos, C.G. da Trindade Neto, S. Filho, M. R. Pereira, J. Fonseca, O. N. Oliveira, L. Mattoso","doi":"10.1109/ISE.2005.1612324","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612324","url":null,"abstract":"Layer-by-layer (LbL) films have been produced with poly(o-ethoxyaniline) (POEA), chitosan and chitosan-poly(methacrylic acid) (CS-PMAA) nanoparticles. Because the adsorption of LbL films depends on ionic interactions and H-bonding, optimized conditions had to be established for the growth of multilayer films. Unusually thick films were obtained for POEA and CS-PMAA, thus demonstrating the importance of using chitosan in the form of nanoparticles","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122627714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmentally robust electret condenser microphone","authors":"Y. Yasuno, Y. Riko, N. Funakoshi, Takeshi Shimizu, G. Yamauchi","doi":"10.1093/ietfec/e89-a.8.2226","DOIUrl":"https://doi.org/10.1093/ietfec/e89-a.8.2226","url":null,"abstract":"A new structure of front filter of ECMs has been introduced to protect in practical use from such common hazards as water or alcohol. This protection structure is composed of acoustically transparent mesh with a water-repellent coating on an electrically-conductive layer. This water-repellent coating has a contact angle of more than 150 degree for water on the filter having less than 50 /spl mu/m aperture which chokes water invasion but is enough for acoustical transmission. The new protection structure also has an electrically conductive layer inside which copes with the induction noise problem by the effect of electrostatic shielding. The reliability of the coating was confirmed by several accelerated tests such as long term immersion in water, heat cycling in the presence of both high and low moisture, heat shocks and surface scratch. These tests showed no damage to the coating. The fabricated electret condenser microphone has met the requirements for the IEC 60526 class 7 which is 30 minutes under water at a depth of 1 meter. The induction noise was reduced by approximately 10 dB at 2 GHz.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"286 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115954195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of charging, transport and reaction processes in Ti/IrO/sub 2/-Nb/sub 2/O/sub 5/ anodes prepared by a sol-gel derived method","authors":"A. Terezo, V.A. Moura, M. Costa, E. Pereira","doi":"10.1109/ISE.2005.1612388","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612388","url":null,"abstract":"In the present work we investigate the charging, transport and reaction processes in Ti/IrO/sub 2/-Nb/sub 2/O/sub 5/ using electrochemical impedance spectroscopy (EIS). The electrochemical impedance response of the electrodes was modeled using the theory of porous electrodes. The spectra for the electrodes in a wide range of composition have shown the typical behavior of a porous structure, exhibiting a straight line with slope of 45/spl deg/ at high frequency and a CPE in the low frequency domain, depending on the applied dc-potential. The spectra were adjusted to the model and the impedance parameters were extracted and analyzed as function of the electrode composition and applied dc voltage.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132012559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Induction and switching of surface optical modes by constant electric field in plane dielectric waveguide","authors":"I. Chupis","doi":"10.1109/ISE.2005.1612433","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612433","url":null,"abstract":"Electromagnetic waves of IR and optical ranges of spectrum in uniaxial insulator with metallic covers in the presence of a constant electric field perpendicular to a waveguide surface have been considered. It is shown that dynamic magnetoelectric interaction induces toroidal excitations which decrease the energy of volume modes transforming it into the surface ones. This effect is proportional to the value of a static electric field and the thickness of the slab. Surface polariton of a given frequency propagates only along one boundary. The changes of the frequency branch or the direction of a constant electric field switch electromagnetic wave from given boundary to another one.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130691815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural rubber electrical conduction mechanism under high and low electrical field","authors":"E. L. Kowalski, R. Robert, J. Tomioka, J. Teixeira, J.C. Tosin, R.E. Clerise, E.O. Filho","doi":"10.1109/ISE.2005.1612391","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612391","url":null,"abstract":"The services in energized line become each more indispensable time and its efficiency depends on the electrician worker who executes this activity. The efficiency of the work passes for the security of the worker, who is protected by tools such as gloves, sleeves, blankets, flexible coverings among others manufactured in natural rubber. The use, storage and maintenance of these tools guarantee the principle the quality and durability of the material, since that its conformation takes care of certain criteria. However is observed that good tools of these materials disapproved when received from manufactures, or when they are removed of the warehouse for replace. This work the experimental results obtained of ageing in temperature of 100/spl deg/C for times the 48, 70 and 312 h, although applying DC electrical tension in samples and measuring leakage current are presented. The measurements in samples were carried out through on samples prepared from the deformulated of commercial materials and respective reformulated in thin films. The obtained results showed to the mechanisms of conduction of the samples in low high e electric field, also identifying the electric tension transition showing that in low fields it prevails to the Ohm law conduction and in high electric fields it is had conduction space charge limited current (SCLC). These results can support the natural rubber formulation process having main objective to reduce the mechanisms that occur high conduction current in high electric fields, which lead the material to dielectric breakdown. Raw natural rubber in Brazil is cropped in rubber tree (Hevea brasiliensis) farm in Sao Paulo State through using new plantation technology in smaller spaces, spaced in few meters between trees. In Amazon forest rubber tree is found naturally and its spacing may be a hundreds meters to kilometers between trees. It's necessary to research this raw material from different internationally standard clones to characterize dielectric and electric properties for industrial applications. Moreover this natural material has a low commercial price compared with synthetic and no necessary to build expensive and dangerous chemical plants.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114723091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reduction of switching transients in the operation of induction motor drives","authors":"M. Venu Gopala Rao, S. Naveed, J. Amaranath, S. Kamakshaiah, B.P. Singh","doi":"10.1109/ISE.2005.1612405","DOIUrl":"https://doi.org/10.1109/ISE.2005.1612405","url":null,"abstract":"The aim of the paper is the study of the over voltages due to switching and current chopping by vacuum circuit breaker in high voltage motor system. Hence these studies will provide means of introducing a suitable protective device surge arrester. The influences of the vacuum circuit breaker's high voltage interrupting capability, cable length, has been traced out to produce a sort of general view of the over voltage phenomena in actual network with surge arrestors. It is seen that high voltage interrupting capability is important for high power motors connected by cables to the vacuum circuit breakers. In the present work transients are reduced up to 21% by using surge arrester.","PeriodicalId":364651,"journal":{"name":"2005 12th International Symposium on Electrets","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116388080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}