Electro-Mechanical Integrity of Nanocellulose- Carbon Nanotube Films
Räty, Anna (2018)
2018
Materiaalitekniikka
Teknisten tieteiden tiedekunta - Faculty of Engineering Sciences
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Hyväksymispäivämäärä
2018-01-10
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201712282500
https://urn.fi/URN:NBN:fi:tty-201712282500
Tiivistelmä
Conducting polymer composites offer an interesting and novel field of applications in electronics for example. Most conventional polymers lack the conducting ability, thus conducting fillers are added. One way to achieve conducting network is the addition of carbon nanotubes (CNTs). Selecting nanocellulose as the matrix material in the nanocomposite offers environmentally friendly and inexhaustible raw material. Important aspect of composite processing is to achieve homogenous and stable dispersion of CNTs in the matrix material.
The purpose of this thesis was to examine the effects of dispersion process parameters. Parameters were the surfactant type and the sonication process, which both were used to enhance the dispersion of conductive fillers. Optimizing the process will give important information and helps further research regarding dispersion of nanocellulose and CNTs. The final outcome is to have optimal dispersion that can be used in future applications. The quality of the dispersions are assessed by analyzing the properties of films which were manufactured from the dispersions. These conductive nanocomposites were manufactured using nanocellulose as the matrix and CNTs as the filler. Four types of surfactants were used to study the influence of different dispersants. The influence of sonication was measured as a function of sonication energy. The primarily interest were electro-mechanical properties of the films. In addition, contact angles measurements and scanning electron microscopy (SEM) imaging were used to characterize surface properties of selected films.
This thesis determined that the optimal surfactant for NFC-CNT combination, based on conductivity of the films, was nonionic by ionic nature. The surfactant was observed to act like a plasticizer in the nanocomposite films, thus removal of surfactant with solvent is recommended to enhance the electro-mechanical properties. The dispersion quality was successfully optimized with sonication and surfactant, which was determined by the fact that no sedimentation occurred in the films. Further research is needed to fully understand the effect of sonication process and the interactions between the materials. Fine adjustment in the composite manufacture and composite composition can have significant outcome and needs to be studied further.
The purpose of this thesis was to examine the effects of dispersion process parameters. Parameters were the surfactant type and the sonication process, which both were used to enhance the dispersion of conductive fillers. Optimizing the process will give important information and helps further research regarding dispersion of nanocellulose and CNTs. The final outcome is to have optimal dispersion that can be used in future applications. The quality of the dispersions are assessed by analyzing the properties of films which were manufactured from the dispersions. These conductive nanocomposites were manufactured using nanocellulose as the matrix and CNTs as the filler. Four types of surfactants were used to study the influence of different dispersants. The influence of sonication was measured as a function of sonication energy. The primarily interest were electro-mechanical properties of the films. In addition, contact angles measurements and scanning electron microscopy (SEM) imaging were used to characterize surface properties of selected films.
This thesis determined that the optimal surfactant for NFC-CNT combination, based on conductivity of the films, was nonionic by ionic nature. The surfactant was observed to act like a plasticizer in the nanocomposite films, thus removal of surfactant with solvent is recommended to enhance the electro-mechanical properties. The dispersion quality was successfully optimized with sonication and surfactant, which was determined by the fact that no sedimentation occurred in the films. Further research is needed to fully understand the effect of sonication process and the interactions between the materials. Fine adjustment in the composite manufacture and composite composition can have significant outcome and needs to be studied further.