Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites
This thesis examines the value of using dispersed conductive fillers as a stress/strain sensing material. The effect of the intrinsic conductivity of the filler on the ability to be effective and the influence of filler concentration on the conductivity are also examined. To meet these objectives, n...
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ndltd-unt.edu-info-ark-67531-metadc680592020-07-15T07:09:31Z Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites Vidhate, Shailesh CNT structural health monitoring PVDF CNF This thesis examines the value of using dispersed conductive fillers as a stress/strain sensing material. The effect of the intrinsic conductivity of the filler on the ability to be effective and the influence of filler concentration on the conductivity are also examined. To meet these objectives, nanocomposites of polyvinylidene fluoride (PVDF) with carbon nanofibers (CNFs) and carbon nanotubes (CNTs) were prepared by melt-blending using a twin screw extruder. Since PVDF has a potential to be piezoresistive based on the type of crystalline phase, the effect of CNFs on PVDF crystallinity, crystalline phase, quasi static and dynamic mechanical property was studied concurrently with piezoresponse. Three time dependencies were examined for PVDF/CNTs nanocomposites: quasi-static, transient and cyclic fatigue. The transient response of the strain with time showed viscoelastic behavior and was modeled by the 4-element Burger model. Under quasi-static loading the resistance showed negative pressure coefficient below yield but changed to a positive pressure coefficient after yield. Under cyclic load, the stress-time and resistance-time were synchronous but the resistance peak value decreased with increasing cycles, which was attributed to charge storage in the nanocomposite. The outcomes of this thesis indicate that a new piezoresponsive system based on filled polymers is a viable technology for structural health monitoring. University of North Texas D'Souza, Nandika Anne, 1967- Vaidyanathan, Vijay Brostow, Witold, 1934- Shepherd, Nigel Chung, Jaycee 2011-05 Thesis or Dissertation Text https://digital.library.unt.edu/ark:/67531/metadc68059/ ark: ark:/67531/metadc68059 English Public Copyright Vidhate, Shailesh Copyright is held by the author, unless otherwise noted. All rights reserved. |
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CNT structural health monitoring PVDF CNF |
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CNT structural health monitoring PVDF CNF Vidhate, Shailesh Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites |
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This thesis examines the value of using dispersed conductive fillers as a stress/strain sensing material. The effect of the intrinsic conductivity of the filler on the ability to be effective and the influence of filler concentration on the conductivity are also examined. To meet these objectives, nanocomposites of polyvinylidene fluoride (PVDF) with carbon nanofibers (CNFs) and carbon nanotubes (CNTs) were prepared by melt-blending using a twin screw extruder. Since PVDF has a potential to be piezoresistive based on the type of crystalline phase, the effect of CNFs on PVDF crystallinity, crystalline phase, quasi static and dynamic mechanical property was studied concurrently with piezoresponse. Three time dependencies were examined for PVDF/CNTs nanocomposites: quasi-static, transient and cyclic fatigue. The transient response of the strain with time showed viscoelastic behavior and was modeled by the 4-element Burger model. Under quasi-static loading the resistance showed negative pressure coefficient below yield but changed to a positive pressure coefficient after yield. Under cyclic load, the stress-time and resistance-time were synchronous but the resistance peak value decreased with increasing cycles, which was attributed to charge storage in the nanocomposite. The outcomes of this thesis indicate that a new piezoresponsive system based on filled polymers is a viable technology for structural health monitoring. |
author2 |
D'Souza, Nandika Anne, 1967- |
author_facet |
D'Souza, Nandika Anne, 1967- Vidhate, Shailesh |
author |
Vidhate, Shailesh |
author_sort |
Vidhate, Shailesh |
title |
Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites |
title_short |
Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites |
title_full |
Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites |
title_fullStr |
Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites |
title_full_unstemmed |
Piezoresistive Polyvinylidene Fluoride/Carbon Filled Nanocomposites |
title_sort |
piezoresistive polyvinylidene fluoride/carbon filled nanocomposites |
publisher |
University of North Texas |
publishDate |
2011 |
url |
https://digital.library.unt.edu/ark:/67531/metadc68059/ |
work_keys_str_mv |
AT vidhateshailesh piezoresistivepolyvinylidenefluoridecarbonfillednanocomposites |
_version_ |
1719328965533892608 |