High Permittivity Nanocomposites Embedded with Ag/TiO2 Core–Shell Nanoparticles Modified by Phosphonic Acid

Abstract

In this paper, nanocomposites that contain core-shell Ag/TiO 2 particles as the filler and polytetrafluoroethylene (PTFE) as the matrix were investigated. Two surfactants, namely octyl phosphonic acid (OPA) and pentafluorobenzyl phosphonic acid (PFBPA), were applied to modify Ag/TiO 2 fillers for uniform dispersion in the matrix. Fourier transform infrared spectroscopy analysis of bonds between the TiO 2 shells and the phosphonic modifiers shows Ti–O–P chemical bonding between the Ag/TiO 2 fillers and the modifiers. Thermogravimetric analysis results show a superior adsorption effect of PFBPA over OPA on the Ag/TiO 2 filler surface at the same weight percentage. For nanocomposites that contain modified Ag/TiO 2 nanoparticles, the loss was reduced despite the high permittivity at the same loading. The permittivity of the nanocomposites by PFBPA is larger than that of OPA, because the more uniform dispersion of inorganic particles in the PTFE matrix enhances the interfacial polarization effect. The mechanism of enhanced dielectric performance was studied and discussed.

Enhanced Dielectric Performance of P(VDF-HFP) Composites with Satellite–Core-Structured Fe2O3@BaTiO3 Nanofillers

“…Two main strategies have been developed by researchers to enhance the dielectric permittivity [5,6,7,8,9,10,11,12]. One is incorporating ceramic fillers with intrinsically high dielectric constants (e.g., BaTiO 3 , Ba x Sr 1-x TiO 3 , CaCu 3 Ti 4 O 12 ) [13,14,15,16,17,18,19,20] into the polymer matrix; the other strategy is employing conductive fillers, including metals (e.g., Ag, Ni, Al) [21,22,23,24,25], carbon materials (e.g., carbon nanotubes, graphene) [26,27,28,29,30,31,32], semiconductors (e.g., ZnO) [33], and conductive polymers (e.g., polyaniline (PANI)) [34,35,36,37]. With ceramic/polymer composites, the merits of high ε r from ceramic fillers and high breakdown strength from polymers are combined.…”

Antibacterial coatings on orthopedic implants

“…Therefore, how to effectively realize the uniform dispersion of nanoparticles in polymer substrate is still a difficult problem to be solved. To address this problem, researchers have also adopted surface modification and in situ generation of nanoparticles [ [199] , [200] , [201] , [202] , [203] , [204] ], but most of the methods involved are complicated and introduce other redundant substances, potentially harming the clinical use, and it is still difficult to achieve uniform dispersion in the real sense. Therefore, more effective and environmentally friendly methods that can realize uniform dispersion of metal nanoparticles remain to be studied.…”

Synthesis, Dielectric and Electrical Properties of Silver-Polymer Nanocomposites

“…Thus, the results showed that the nanocomposites by PFBPA exhibits higher permittivity than the OPA because of its uniform dispersion stability of inorganic fillers into the PTFE polymer matrix and results increase the interfacial polarization effect. Therefore, nanocomposites could be used as better promising materials for applications of embedded devices and high frequency fields in electronics [87].…”