Effect of Silica Modification on Charge Trapping Behavior of PP blend/Silica Nanocomposites

Mahtabani, Amirhossein; He, Xiaozhen; Rytöluoto, Ilkka; Paajanen, Mika; Saarimäki, Eetta; Anyszka, Rafał; Dierkes, Wilma K.; Blume, Anke

doi:10.1109/icempe.2019.8727245

Cited by 4 publications

(2 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the influence of modified nanofillers having different surface polarities on the charge trapping properties of the dielectric materials is studied. Previously, the introduction of different polar functional groups on the silica surface resulted in significant differences in charge trapping properties of the nanocomposites [13], [14]. Following up our previous study [14], the current research not only covers the phenomenon of charge trapping properties, but also includes various characterization methods to investigate the mechanism of it.…”

Section: Introductionmentioning

confidence: 92%

Silica Surface-Modification for Tailoring the Charge Trapping Properties of PP/POE Based Dielectric Nanocomposites for HVDC Cable Application

Rytöluoto

Anyszka

et al. 2020

IEEE Access

Self Cite

View full text Add to dashboard Cite

This paper focuses on novel insulation polypropylene/poly(ethylene-co-octene) (PP/POE) nanocomposites for High Voltage Direct Current (HVDC) cable application. The composites contain silica modified by a solvent-free method using silanes differing in polarity and functional moieties. Thermogravimetric Analysis and Fourier Transform Infrared Spectroscopy showed that the solvent-free method is an effective way to modify silica by silanes. Silica/PP/POE nanocomposites were prepared in a mini twin-screw compounder, and the effect of silica on crystallization, dispersibility and dielectric properties of the samples was investigated. Differential Scanning Calorimetry results showed that the unmodified and modified silicas acted as nucleation agents and increased the onset of the crystallization temperature of the polymeric matrix. Scanning Electron Microscopy images showed that the silica is mostly located in the PP phase matrix. For the PP/POE nanocomposites filled with unpolar silica, a higher trap density (measured by Thermally Stimulated Depolarization Current, TSDC) was found; this might be caused by the larger interfacial area due to a better dispersion of the unpolar silica in the polymeric matrix. Polar silicas introduce deeper traps than the unpolar ones, which is most likely due to the hetero-atom introduction. Nitrogen atoms were found to have the strongest effect on the charge trapping properties. According to these results, amine-modified silica is a promising candidate for PP/POE nanocomposites for HVDC cable applications.

show abstract

Section: Introductionmentioning

confidence: 92%

Silica Surface-Modification for Tailoring the Charge Trapping Properties of PP/POE Based Dielectric Nanocomposites for HVDC Cable Application

Rytöluoto

Anyszka

et al. 2020

IEEE Access

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is evident that upon incorporation of the unmodified NPs, the onset of crystallization decreases despite the expected nucleating effect of NPs [40,41]. This is likely due to the adsorption of the polar antioxidant particles onto the silica surface, resulting in fewer nucleating sites in the matrix [42,43]. For the same reason, the degree of crystallinity is not affected by the addition of the untreated silica.…”

Section: Figure 3 Drifts Spectra For the Modified And Unmodified Npsmentioning

confidence: 98%

Deposition of Ureido and Methacrylate Functionalities Onto Silica Nanoparticles and its Effect on the Properties of Polypropylene-Based Nanodielectrics

Mahtabani¹,

Niittymaki

Anyszka

et al. 2021

IEEE Access

Self Cite

View full text Add to dashboard Cite

Surface modification of nanoparticles is often utilized to tailor the interfacial properties in dielectric nanocomposites. Introducing different functional groups to the nanoparticles' surface may induce localized states (traps) that can enhance the dielectric performance of the material depending on their density and energy levels. Furthermore, surface modification of the filler can affect the dispersion quality and crystallization of the nanocomposites which can ultimately alter the dielectric response of the material. In this study, functionalization of silica nanoparticles is demonstrated using 3-(trimethoxysilyl)propyl methacrylate (TMPM) and 1-[3-(trimethoxysilyl)propyl]urea (TMPU) as modifying agents. The effect of such modifications on the crystallization behavior, dispersion quality of the nanoparticles, as well as charge trapping and transport under a medium DC field is studied in nanocomposites based on polypropylene (PP)/ethylene-octene-copolymer (EOC) blends at 1% and 5% of filler concentrations. The results show that both ureido and methacrylate functional groups introduce localized states, but with different energy levels. Nitrogen containing ureido groups in TMPU tend to introduce deeper traps to the filler-polymer interfaces, compared to the methacrylate silane modification. Comparing the two types of surface functionalization, the ureido-functionalized silica resulted in a suppression of space charge formation at the interfaces under a medium DC electric field, despite the relatively larger mean cluster size of nanoparticles.

show abstract

Molecular Layer Deposition of Polyurea on Silica Nanoparticles and Its Application in Dielectric Nanocomposites

et al. 2023

Self Cite

View full text Add to dashboard Cite

Polymer nanocomposites (NCs) offer outstanding potential for dielectric applications including insulation materials. The large interfacial area introduced by the nanoscale fillers plays a major role in improving the dielectric properties of NCs. Therefore, an effort to tailor the properties of these interfaces can lead to substantial improvement of the material’s macroscopic dielectric response. Grafting electrically active functional groups to the surface of nanoparticles (NPs) in a controlled manner can yield reproducible alterations in charge trapping and transport as well as space charge phenomena in nanodielectrics. In the present study, fumed silica NPs are surface modified with polyurea from phenyl diisocyanate (PDIC) and ethylenediamine (ED) via molecular layer deposition (MLD) in a fluidized bed. The modified NPs are then incorporated into a polymer blend based on polypropylene (PP)/ethylene-octene-copolymer (EOC), and their morphological and dielectric properties are investigated. We demonstrate the alterations in the electronic structure of silica upon depositing urea units using density functional theory (DFT) calculations. Subsequently, the effect of urea functionalization on the dielectric properties of NCs is studied using thermally stimulated depolarization current (TSDC) and broadband dielectric spectroscopy (BDS) methods. The DFT calculations reveal the contribution of both shallow and deep traps upon deposition of urea units onto the NPs. It could be concluded that the deposition of polyurea on NPs results in a bi-modal distribution of trap depths that are related to each monomer in the urea units and can lead to a reduction of space charge formation at filler-polymer interfaces. MLD offers a promising tool for tailoring the interfacial interactions in dielectric NCs.

show abstract

Effect of Silica Modification on Charge Trapping Behavior of PP blend/Silica Nanocomposites

Cited by 4 publications

References 17 publications

Silica Surface-Modification for Tailoring the Charge Trapping Properties of PP/POE Based Dielectric Nanocomposites for HVDC Cable Application

Silica Surface-Modification for Tailoring the Charge Trapping Properties of PP/POE Based Dielectric Nanocomposites for HVDC Cable Application

Deposition of Ureido and Methacrylate Functionalities Onto Silica Nanoparticles and its Effect on the Properties of Polypropylene-Based Nanodielectrics

Molecular Layer Deposition of Polyurea on Silica Nanoparticles and Its Application in Dielectric Nanocomposites

Contact Info

Product

Resources

About