Schulich School of Engineering
Effect of Processing Techniques and Blend Compositions on Electrical Properties of Immiscible Polymer Blend/MWCNT Nanocomposites
Abstract
dc:description.abstractElectronic devices radiate harmful electromagnetic (EM) waves, which cause EM pollution. We need to shield EM pollution to protect human health and to ensure efficiency of electronic devices. Conductive polymer blend nanocomposite is a potential option to mitigate the challenges associated with commercially-used metal shields. This work aims to attain improved electrical conductivity, electromagnetic interference shielding effectiveness (EMI SE) and dielectric property in immiscible polymer blend nanocomposites. In chapter 4, we have reported three strategies to mix 3 wt % multi-walled carbon nanotube (MWCNT) in five blend compositions of polystyrene (PS)/poly (vinylidene fluoride) (PVDF) blend system. In chapter 5, six techniques are mentioned to mix 2.7 vol % MWCNT in three compositions of PS/poly (methyl methacrylate) (PMMA) blend. Mixing strategy influences filler localization and dispersion. Consequently, we see variations in electrical conductivity, EMI SE and dielectric properties in the blend nanocomposites. The strategy of premixing 3 wt % MWCNT with PS phase has attained 19 dB EMI SE (commercially-significant value) in 1 mm thick PS/PVDF (70:30) blend nanocomposite at a much lower cost than PVDF/MWCNT nanocomposite, reported in chapter 4. Moreover, EMI SE and complex permittivity are found to show a linear correlation (R2 ≥ 0.94). This observation is valid for all the processing techniques and blend compositions, explored in PS/PVDF/MWCNT system. This finding shows the significance of dielectric parameters to attain improved EMI SE in immiscible polymer blend nanocomposite. It has been reported in chapter 5 that one-step solution mixing technique exhibits more than 20 dB EMI SE in 0.8 mm thick samples of PS/PMMA (20:80) and (80:20) nanocomposites, containing 2.7 vol % MWCNT.EMI SE of nanocomposites is observed to increase with sample thickness. This increment is higher in blend nanocomposites than in single polymer/MWCNT nanocomposites. Improved EMI SE in immiscible blend nanocomposites is attributed to selective localization-assisted interphase scattering and better dispersion-promoted intertube scattering of incident EM wave. However, only intertube scattering is active in single polymer/MWCNT nanocomposite. This thesis provides detailed information about the effect of processing techniques and blend compositions on nanofiller localization, dispersion and finally electrical properties of immiscible polymer blend nanocomposites.
Degree
thesis:*- Name thesis:degree_name
- Master of Science (MSc)
- Discipline thesis:degree_discipline
- Engineering – Chemical & Petroleum
- Grantor dc:publisher.institution
- Schulich School of Engineering
- Year dc:date.issued
- 2019
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Sultana, S. M. Nourin
- Advisor dc:contributor.advisor
-
- Sundararaj, Uttandaraman
- Committee members dc:contributor.committeemember
-
- Ponnurangam, Sathish
- Sudak, Leszek Jozef
Subjects
dc:subject × 6Rights
dc:rights- Statement dc:rights
-
- University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
- Language dc:language.iso
- en
Identifiers
dc:identifier.*- OAI identifier oai:identifier
- oai:ucalgary.scholaris.ca:1880/109928