The nanocomposites show Epacadostat ic50 a low composition dependency at higher frequencies, since the dielectric behavior is dominated by the copolymer phase. The PVP films exhibit lower dielectric permittivity (Figure 4d) because the PVP polymer possesses a lower intrinsic dielectric constant of 5.1 (at 100 Hz) [29]. Figure 4 Effective permittivity and loss tangent of the ferrites / polymer thin films. Effective permittivity (a) and loss tangent (b) of CFO/P (VDF-HFP) nanocomposite thin films
with CFO Citarinostat molecular weight fractions from 0 to 30 wt.%. (c) Effective permittivity of the CFO/P(VDF-HFP) as a function of composition at 100 to 1 MHz. (d) Effective permittivity of CFO/PVP films. For 0–3 type nanocomposites with high permittivity nanocrystal fillers discretely distributed in a ferroelectric polymer matrix, the effective permittivity of the films is calculated by the Emricasan modified Kerner model (or Kerner equation) [30, 31] as shown in Equation 1: (1) where (2) and (3) The effective permittivity of the films, ϵ eff, is predicted using an average of the host and the filler particle permittivities (ϵ h and ϵ f), wherein the contributions are weighted by the fraction of each component (f f for filler and f h for host, Equation 1). The measured effective permittivities and those calculated from the modified Kerner
model for both PVDF-HFP and PVP films are summarized in Table 1. Table 1 Comparison of effective permittivity of the CFO/polymer films at 100 kHz from experimental and modified Kerner model Sample PRKD3 ϵ eff(measured)
ϵ eff(calculated from Kerner equation) Δϵ eff P(VDF-HFP) films 10 wt.% CFO 9.1 7.3 +1.8 20 wt.% CFO 19.08 13.44 +5.64 30 wt.% CFO 28.56 19.71 +8.85 PVP films 10 wt.% CFO 9.17 8.82 +0.35 20 wt.% CFO 14.59 13.62 +0.97 30 wt.% CFO 18.05 19.90 −1.85 The effective permittivity of the CFO/P(VDF-HFP) films shows a distinctive and continuous increase relative to the theoretical value estimated by the Kerner model, contrary to the expectations based solely on a composited effective dielectric constant. This can be contrasted with CFO/PVP, which shows significantly less deviation between experiment and theory, and follows expected behavior for a simple combination of two components for ϵ eff . This observation, of deviating behavior in the case of CFO/P(VDF-HFP), is interesting and strongly suggests additional interactions between the polymer and nanoparticle. The phenomenon is ascribed to interfacial interactions between the magnetic filler and the piezoelectric matrix. P(VDF-HFP) undergoes lattice distortion under an applied electric field due to the piezoelectric effect, which introduces local stresses and strain at the ferrite-copolymer interface. Since the thermal shrinkage nature of the P(VDF-HFP) makes complete mechanical coverage of the copolymer over the CFO nanocrystals, and both CFO and P(VDF-HFP) are mechanically hard phases, with Young’s modulus of 141.
Related posts:
- We examine how well the new model fits the data, and show that it
- Methods In this manuscript, we only consider the case of weak QE-
- The larger particles, which have a nominal stress response that a
- J Non-Crystalline Solids 2008, 354:2809–2815 CrossRef 10 Alberti
- The data show that, in contrast to humans, pDC in macaques are ab