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Doctoral Thesis
DOI
https://doi.org/10.11606/T.54.1990.tde-09062009-094916
Document
Author
Full name
Walter Katsumi Sakamoto
Institute/School/College
Knowledge Area
Date of Defense
Published
São Carlos, 1990
Supervisor
Committee
Gonzalez, Ernesto Rafael
Oliveira Junior, Osvaldo Novais de
Stradiotto, Nelson Ramos
Ticianelli, Edson Antonio
Zimmerman, Robert Lee
Title in Portuguese
Efeito da deformação mecânica no transporte iônico em filmes poliméricos.
Keywords in Portuguese
Absorção
Difusão
Pares iônicos
Permeabilidade
Potencial de membrana
Abstract in Portuguese
Recentemente um efeito piezoelétrico foi encontrado quando um filme polimérico, separando duas soluções de eletrólitos em diferentes concentrações, foi deformado. Este efeito foi atribuído à modulação da mobilidade dos íons no polímero. Foi observado que o efeito diminui com o aumento da concentração de eletrólitos. Para entender mais profundamente este último efeito, foram realizados estudos sobre o transporte de água e sal através do polímero, com e sem deformação, e os resultados podem ser resumidos como segue: a) O aumento da hidratação acarreta um aumento na porosidade e um decréscimo na cristalinidade do polímero. b) O aumento da concentração de sal, no interior do polímero acarreta um aumento na permeabilidade, sendo mais pronunciado na presença de deformação. Esses efeitos tornam mais difícil a modulação dos íons, diminuindo o sinal piezoelétrico observado.
Title in English
Effect of mechanical deformation on ionic transport in polimeric films.
Keywords in English
Absorption
Difusion
Ionic pair
Membrane potential
Permeability
Abstract in English
Recently a piezoelectric effect was found when a polymeric film, separating two electrolyte solutions at different concentrations, was deformed. This effect was attributed to the modulation of the mobility of the íons in the polymer. It was observed that the effect decreases as the electrolyte concentrations increases. In order to understand more deeply this last effect a study on water and salt transport through the polymer with and without deformation was carried out, and the results may be summarized as follows: a) An increase in hydration of the polymer leads to an increase in porosity and a decrease in cristallinity. b) An increase in the concentration of the salt leads to an increase in permeability, which is more pronounced in the presence of deformation. The effects make more difficult the modulation of the íons, so lower piezoelectric signals are observed.
 
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Publishing Date
2009-06-15
 
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