The tunable permittivity of multi-walled carbon nanotubes/silver nanoparticles reinforced polyvinyl alcohol (PVA) nanocomposites at low frequency

• Main Authors: Yusof, Yusliza, Ng, Zi Yi, Wong, Yew Hoong, Johan, Mohd Rafie
• Format: Article
• Published: IOP Publishing 2018
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.um.edu.my/20233/; https://doi.org/10.1088/2053-1591/aad442
• Institution: Universiti Malaya

This paper is about tailoring high permittivity of multi-walled carbon nanotubes/silver nanoparticles (MWNT-AgNP) filled polyvinyl alcohol (PVA) nanocomposites at low frequency. PVA/MWNT-AgNP nanocomposites were synthesized via solution-casting technique at low MWNT content with different loading of AgNP. The nanocomposites showed a significant increment in ac conductivity, σ ac, and dielectric permittivity, ϵ′ by two orders of magnitude as compared to pure PVA. The maximum ϵ′ value was achieved about 600 at 1.0 wt% of AgNP due to the increased charge carriers density and high interfacial polarization within the nanocomposites. The relaxation frequency was shifted towards a higher value with the increased of AgNP content while the relaxation time was decreased by 40%. Field emission scanning electron microscopy (FESEM) images showed the enhanced distribution of MWNT in the presence of AgNP to provide conductive pathways in the matrix. This was confirmed by energy-dispersive x-ray (EDX) analysis and ultraviolet-visible (UV-vis) spectroscopy. As a result, PVA/MWNT-AgNP nanocomposites have great potential for electrical applications such as cable accessories, high charge-storage capacitor and electromagnetic interference shielding materials.