Combining good dispersion with tailored charge trapping in nanodielectrics by hybrid functionalization of silica
He Xiaozhen,
Rytöluoto Ilkka,
Anyszka Rafal,
Mahtabani Amirhossein,
Niittymäki Minna,
Saarimäki Eetta,
Mazel Christelle,
Perego Gabriele,
Lahti Kari,
Paajanen Mika,
Dierkes Wilma,
Blume Anke
Affiliations
He Xiaozhen
University of Twente, Faculty of Engineering Technology, Department of Mechanics of Solids, Surfaces and Systems (MS3), Chair of Elastomer Technology and Engineering, 7522 NB, Enschede, The Netherlands
Rytöluoto Ilkka
VTT Technical Research Centre of Finland Ltd, FI-33720, Tampere, Finland
Anyszka Rafal
University of Twente, Faculty of Engineering Technology, Department of Mechanics of Solids, Surfaces and Systems (MS3), Chair of Elastomer Technology and Engineering, 7522 NB, Enschede, The Netherlands
Mahtabani Amirhossein
University of Twente, Faculty of Engineering Technology, Department of Mechanics of Solids, Surfaces and Systems (MS3), Chair of Elastomer Technology and Engineering, 7522 NB, Enschede, The Netherlands
Niittymäki Minna
Tampere University, High Voltage Engineering, 33100, Tampere, Finland
Saarimäki Eetta
VTT Technical Research Centre of Finland Ltd, FI-33720, Tampere, Finland
Mazel Christelle
Nexans Research Center, 29 Rue Pré Gaudry, 69007 Lyon, France
Perego Gabriele
Nexans Research Center, 29 Rue Pré Gaudry, 69007 Lyon, France
Lahti Kari
Tampere University, High Voltage Engineering, 33100, Tampere, Finland
Paajanen Mika
VTT Technical Research Centre of Finland Ltd, FI-33720, Tampere, Finland
Dierkes Wilma
University of Twente, Faculty of Engineering Technology, Department of Mechanics of Solids, Surfaces and Systems (MS3), Chair of Elastomer Technology and Engineering, 7522 NB, Enschede, The Netherlands
Blume Anke
University of Twente, Faculty of Engineering Technology, Department of Mechanics of Solids, Surfaces and Systems (MS3), Chair of Elastomer Technology and Engineering, 7522 NB, Enschede, The Netherlands
Fumed silica-filled polypropylene (PP)-based nanodielectrics were studied in this work. To not only improve the dispersion of the silica but also introduce deep charge traps into the polymeric matrix, five types of modified silicas were manufactured with different surface modifications. The modified silica surfaces comprise an inner and a surface layer. The inner layer contains a polar urethane group for tailoring the charge trap properties of the PP/propylene–ethylene copolymer nanocomposites, whereas the surface layer consists of hydrocarbons (ethyl-, tert-butyl-, cyclopentyl-, phenyl-, or naphthalenyl moieties) in order to gain a good dispersion of the silica in the unpolar polymer blend. Scanning electron microscopic pictures proved that these tailored silicas show a much better dispersion than the unmodified one. Thermally stimulated depolarization current measurements revealed the ability of the silica to introduce deep charge traps with low trap density. The trap depth distribution depends on the type of the unpolar surface layer consisting of the different hydrocarbons. Among these five differently modified silicas, the introduction of the one with a surface layer consisting of tert-butyl moieties resulted in the lowest charge injection and the lowest charge current in the nanocomposite, proving good dielectric performance. Additionally, this silica exhibits good dispersion in the polymeric matrix, indicating a promising performance for nanodielectric application.