In this study, MWCNTs were used as a filler for epoxy thin film composites, where the thin film was fabricated using the spin coating method. We investigated the dielectric properties of the MWCNT-filled epoxy composite, with filler loading in the range from 0 to 1.5 vol%. Additionally, the effect of various type of MWCNT filler treatments using polyoxyethylene octyl phenyl ether (Triton X-100), sodium dodecyl sulfate (SDS) and 3-aminopropyltriethoxy silane (AMPTES) on the dielectric properties of epoxy thin film composites were investigated. The results showed that the increment of MWCNT loading increased the dielectric properties of the composite system. Meanwhile, chemically treated MWCNTs, especially MWCNT treated with SDS, showed good dielectric properties. Furthermore, morphological study showed an improvement in the dispersion of filler throughout the epoxy matrix in the treated composite system compared to the untreated system. TEM images also showed that treated MWCNT filler increased wall thickness of nanotube.

The minerals silica, mica, and calcium carbonate (CaCO3) were used as fillers to produce epoxy thin film composites for capacitor application. The effects of filler loading and type on the morphology, tensile, dielectric, and thermal properties of the epoxy thin film composites were determined. Results showed that epoxy thin films with 20 vol% filler loading showed good dielectric properties, thermal conductivity, and thermal stability. However, the tensile properties of the thin films were reduced as the filler loading was increased due to brittleness. Dielectric constant and dielectric loss of epoxy/inorganic composite films generally increased with increasing mineral filler loading. Meanwhile, the presence of mineral filler improved the thermal stability of the thin film composites. The highest dielectric constant of 5.75 with 20 vol% filler loading at a frequency of 1 MHz was exhibited by the epoxy/CaCO3 composite, followed by epoxy/mica and epoxy/silica. Therefore, the epoxy/CaCO3 composite is the most potential candidate for capacitor application. Moreover, precipitated CaCO3 provided better tensile properties and slightly improved the dielectric properties compared with mineral CaCO3.

olymer ceramic composite materials are candidate material for capacitor application. In this research, MWCNT and BaTiO3 were used as fillers in epoxy thin film composites where the filler loading was in the range of 0 to 2.0 vol%. The thin film composites were fabricated by using spin coating method. The dielectric constant and dielectric loss were measured at 100 Hz to 1 MHz. The dielectric constant of CNT was in the range of 3.5 to 243.7 whereas the dielectric constant of BaTiO3 was 3.5 to 33.7 at 1 kHz. Meanwhile the dielectric loss of MWCNT was 0.009 to 6.83 while dielectric loss of BaTiO3 was 0.009 to 0.016 at 1 kHz. In general, it was found that MWCNT filler provide high dielectric constant value compare to BaTiO3 this is because MWCNT is more conductive than BaTiO3. However MWCNT/epoxy composites exhibit higher dielectric loss compare to BaTiO3/epoxy composites.

In this study, the authors attempted to enhance the flexural and dielectric properties of epoxy resin using advanced carbon nanotube–alumina (CNT–Al2O3) hybrid filler system that was chemically synthesised via chemical vapor deposition (CVD). The hybrid CNT–Al2O3 filled epoxy composite was compared to the physically mixed CNT–Al2O3 filled epoxy composites. The assessment showed that the CNT–Al2O3 hybrid filler produced more homogeneous dispersion in the epoxy matrix with higher flexural and dielectric properties as compared to the physically mixed CNT–Al2O3 filler. The flexural strength, flexural modulus and dielectric constant of CNT–Al2O3 hybrid epoxy composites improved significantly up to 30%, 35% and 20%, respectively, compared to the neat epoxy.

This paper presents the properties of epoxy nanocomposites, prepared using a synthesized hybrid carbon nanotube–alumina (CNT–Al2O3) filler, via chemical vapour deposition and a physically mixed CNT–Al2O3 filler, at various filler loadings (i.e., 1–5%). The tensile and thermal properties of both nanocomposites were investigated at different weight percentages of filler loading. The CNT–Al2O3 hybrid epoxy composites showed higher tensile and thermal properties than the CNT–Al2O3 physically mixed epoxy composites. This increase was associated with the homogenous dispersion of CNT–Al2O3 particle filler; as observed under a field emission scanning electron microscope. It was demonstrated that the CNT–Al2O3 hybrid epoxy composites are capable of increasing tensile strength by up to 30%, giving a tensile modulus of 39%, thermal conductivity of 20%, and a glass transition temperature value of 25%, when compared to a neat epoxy composite.

This paper presents the multi-scale hybridization of carbon nanotube (CNT) with microparticles in polymers which offers new opportunity to develop high performance multifunctional composites. The hybrid carbon nanotube-alumina (CNT-Al2O3) compound was synthesized via chemical vapour deposition (CVD) by direct growth of CNT on alumina particles. This hybrid CNT-Al2O3 compound was incorporated into the epoxy matrix at various filler loadings (i.e., 1–5%) and compared to physically mixed CNT-Al2O3. The CNT-Al2O3 hybrid epoxy composites showed higher hardness compared to the CNT-Al2O3 physically mixed epoxy composites. This enhancement was associated with the homogenous dispersion of CNT-Al2O3 hybrid compound in the epoxy matrix.

A novel hybrid carbon nanotube-muscovite (CNT-muscovite) compound was synthesized via chemical vapour deposition (CVD) by directly grown CNT on muscovite particles. The synthesis of CNT using nickel catalyst and muscovite as a substrate material is rarely found. Morphological analysis using scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) showed that the CNT was successfully grown on muscovite flaky particles. The CNT-muscovite compound can be potentially used as a new class of filler in polymer composites technology.

This paper presents a case study of an intermittent audio failure analysis of a remote speaker-microphone module for a two-way radio. A root cause analysis was undertaken to identify probable causes of the intermittent failure, followed by a series of experiments to determine the strength and the intermittent audio failure load of cable components and the fully assembled cable. The combined experimental and finite element results demonstrated that the main contributor of the intermittent audio failure was the micro surface cracks on the copper conductor strands. In addition, the combination of the component materials and design of the cable have also contributed to the non-uniform state of residual stress induced in the copper conductors which have reduced the ability of the copper conductors to withstand the normal handling load under the influence of micro surface cracks.