Polymer Composites for Electrical Engineering. Группа авторов

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Polymer Composites for Electrical Engineering - Группа авторов

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in optimizing the dielectric properties of the shell layer. The mismatch of the electrical parameters (i.e. dielectric constant and electrical resistivity) of the nanofillers and polymer matrix would result in local electric field concentration at the nanofiller/polymer interface, which largely decreases the electrical breakdown strength of the polymer composites. In order to mitigate the electric field concentration, the shell layer of the core‐shell structured nanofillers can act as a buffer layer by carefully controlling the electrical parameters of the shell layer. For example, the shell layer with medium dielectric constant between the high‐dielectric‐constant nanofillers and the low‐dielectric‐constant polymer matrix can obviously mitigate the local electric field distortion.

Schematic illustration of (a) the preparation process of the core-shell structured polymer@BT nanoparticles by surface-initiated RAFT, (b) breakdown strength, and (c) leakage current density at 100 kV/mm of the polymer@BT-based PVDF composites.

      Source: Zhu et al. [63]. Reproduced with permission of American Chemical Society.

      In addition to the polymer shell layers, inorganic materials including SiO2, TiO2, and Al2O3 have been employed as the shell layers of the core‐shell structured nanofillers [70–74]. The highly insulated shell layers, such as SiO2 and Al2O3, can serve as a barrier layer to suppress the electrical conduction and breakdown, yielding increased electrical breakdown strength and charge/discharge efficiency. The shell layers with medium dielectric constant, such as TiO2, can act as a buffer layer to mitigate the local electric field distortion in the high‐dielectric‐constant nanofiller/polymer composites. Moreover, the core‐shell structured strategy is also applicable to the high‐aspect‐ratio 1D and 2D nanofillers.

      Schematic illustration of (a) the preparation of the core-shell structured pp-mah-mgo nanoparticles, (b) tem image of the pp-mah-mgo nanoparticle, (c) local charge trap level distribution at the interfacial region obtained from nano-ispd measurement, (d) frequency-dependent dielectric constant and dissipation factor at room temperature, (e) temperature-dependent breakdown strength, and (f) discharged energy density and charge/discharge efficiency at 120 °C. Schematic illustration of (a) thepreparation of the core-shell structured pp-mah-mgo nanoparticles, (b) tem image of the pp-mah-mgo nanoparticle, (c) local charge trap level distribution at the interfacial region obtained from nano-ispd measurement, (d) frequency-dependent dielectric constant and dissipation factor at room temperature, (e) temperature-dependent breakdown strength, and (f) discharged energy density and charge/discharge efficiency at 120 °C.

      Source: zhou et al. [69]. Reproduced with permission of elsevier.

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