Development, characterization, energy storage and interface dielectric properties in SrFe 12 O 19 / epoxy nanocomposites

Sanida, A.; Stavropoulos, S.G.; Speliotis, Th.; Psarras, G. C.

doi:10.1016/j.polymer.2017.05.043

Cited by 40 publications

(17 citation statements)

References 31 publications

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“…The loss peaks for the GnP filled nanocomposites remain invariable with filler concentration. This behaviour is attributed to the good adhesion of the filler with the polymer matrix and an equilibrium between the macromolecules-particles and particlesparticles interactions [29,30]. The variations of the electrical response induced by the different carbon allotropes are clearly illustrated at Figure 7, which depicts the real part of dielectric permittivity (as an inset) and the AC conductivity versus frequency respectively, at 30°C for nanocomposites with different nanoinclusions at the same filler content.…”

Section: Resultsmentioning

confidence: 97%

A comparative study on the electrical properties of different forms of carbon allotropes – epoxy nanocomposites

Stavropoulos¹,

Sanida²,

Psarras³

2020

Express Polym. Lett.

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In this study, series of nanocomposites consisting of an epoxy matrix and different carbon nanoinclusions (Carbon Black, Multiwall Carbon Nanotubes (MWCNT), Graphene nanoplatelets (GnP) and nanodiamonds) were developed, and their electrical response was examined in wide frequency and temperature ranges. Depending on the filler type and concentration, nanocomposites exhibited either insulator to conductor transitions or dielectric relaxation phenomena. Recorded relaxations were attributed to interfacial polarization, glass to rubber transition and motion of polar side groups. Nanocomposites integrating carbon black or MWCNTs exhibit an abrupt increase in permittivity and conductivity at a critical concentration (or percolation threshold). The insulator to conductor transition is described by means of percolation theory and critical concentration and exponent are determined. Conductance mechanisms are investigated in all sets of nanocomposites, by accounting the influence of temperature on conductivity and by applying the Variable Range Hopping model. Further, analysis reveals hopping conductivity as the main charge migration process below critical concentration, while hopping and metallic-like conduction coexist above it.

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Section: Resultsmentioning

confidence: 97%

A comparative study on the electrical properties of different forms of carbon allotropes – epoxy nanocomposites

Stavropoulos¹,

Sanida²,

Psarras³

2020

Express Polym. Lett.

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“…Charge transport properties in polymer matrix nanocomposites are affected by several parameters, including the geometric characteristics of the nanoinclusions, the interaction between particles, the interactions between macromolecules and inclusions, the extent of aggregation of filler particles, the extend and properties of interface, the strength of disorder and the rheological behaviour of the matrix [8]. Particle-particle interactions and macromolecules-particles interactions constitute two competitive mechanisms influencing the mobility of polar parts of the polymer chains, interface response, and possibly trapping of charge carries at the systems' interface or isolated conductive sites [19,20]. Under this point of view, activation energy could vary with filler content reflecting the prevalent type of interactions, each time.…”

Section: Conductivity/theoretical Considerations and Calculationsmentioning

confidence: 99%

Barium titanate/epoxy resin composite nanodielectrics as compact capacitive energy storing systems

Manika¹,

Psarras²

2019

Express Polym. Lett.

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Barium titanate/epoxy resin composite nanodielectrics were manufactured and their capability to store and harvest energy, upon request under DC conditions, was studied in this work. Morphological characterization in all nanocomposites was performed via scanning electron microscopy images and X-ray diffraction spectra, indicating the successful nanofiller's integration and dispersion within the polymer matrix. Applied DC voltage level varied from 10 to 240 V and the measurements were performed in the temperature range from 30 to 160°C. Filler content enhances the energy efficiency of the manufactured systems, reaching the highest value of 58.2% for the 7 phr BaTiO 3 nanocomposite. Increase of temperature results in an exponential decay of the coefficient of energy efficiency (n eff), indicating leakage currents' augment. DC and AC conductivity have been determined as a function of temperature for all nanodielectric systems. The temperature dependence of conductivity under DC and AC condition follows an Arrhenius form, which allowed the determination of activation energy in both cases.

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“…With the aim of elucidating the processes involved in conduction in cement-based materials and, in particular, of investigating the role of water molecules and the indirect impact of the addition of fillers, we studied graphene nanoplatelets/cement composite by means of dielectric spectroscopy technique at different temperatures. Such a technique, commonly used to study conductivity in ceramic materials [47][48][49][50][51][52] and dielectric and electrical properties of porous systems [53][54][55][56][57][58][59][60] and polymer composite [61][62][63][64][65][66][67][68], is a very suitable tool due to its unique properties. In fact, due to its large frequency range, it is possible to investigate the impedance and dielectric response of the material on different time scale and, therefore, to obtain information on the different processes involved in the ionic and electronic conduction phenomena.…”

Section: Introductionmentioning

confidence: 99%

Elucidation of Conduction Mechanism in Graphene Nanoplatelets (GNPs)/Cement Composite Using Dielectric Spectroscopy

Goracci

Dolado

2020

Materials

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Understanding the mechanisms that govern the conductive properties of multifunctional cement-materials is fundamental for the development of the new applications proposed to enhance the energy efficiency, safety and structural properties of smart buildings and infrastructures. Many fillers have been suggested to increase the electrical conduction in concretes; however, the processes involved are still not entirely known. In the present work, we investigated the effect of graphene nanoplatelets (1 wt% on the electrical properties of cement composites (OPC/GNPs). We found a decrease of the bulk resistivity in the composite associated to the enhancement of the charge transport properties in the sample. Moreover, the study of the dielectric properties suggests that the main contribution to conduction is given by water diffusion through the porous network resulting in ion conductivity. Finally, the results support that the increase of direct current in OPC/GNPs is due to pore refinement induced by graphene nanoplatelets.

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Development, characterization, energy storage and interface dielectric properties in SrFe 12 O 19 / epoxy nanocomposites

Cited by 40 publications

References 31 publications

A comparative study on the electrical properties of different forms of carbon allotropes – epoxy nanocomposites

A comparative study on the electrical properties of different forms of carbon allotropes – epoxy nanocomposites

Barium titanate/epoxy resin composite nanodielectrics as compact capacitive energy storing systems

Elucidation of Conduction Mechanism in Graphene Nanoplatelets (GNPs)/Cement Composite Using Dielectric Spectroscopy

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