Narrow Results

The composite (PPy/CuO) films are created using the solution casting solution method by mixing the polymer polypyrrole (PPy) with copper oxide nanoparticles (CuONPs) at different concentrations of CuO (4%, 6% and 8%). The XRD confirms the effective fabrication of the composite (PPy/CuO). The impact of CuO on the optical and structural characteristics was studied. The addition of CuO enhances the refractive indices ($n_o)$ of PPy from 1.42 for pure PPy to 1.55 for PPy with 4% CuO, and further to 1.69 for PPy with 8% CuO. The dispersion energy of pure polypyrrole (PPy) is 4.55eV, which increased to 5.31eV when doped with 4% CuO. Furthermore, the increasing of CuO concentration to 6% and 8% resulted in higher dispersion energies, respectively, of 5.87 and 6.14eV. The oscillation energy $E_0$ decreased from 4.43eV for PPy to 3.76, 3.41 and 3.25eV for PPy/4%CuO, PPy/6%CuO and PPy/8%CuO, correspondingly. The introduction of CuO into the PPy polymer results in modifications to its optical characteristics. Additionally, there was an observed rise in the plasma frequency from $0.04\times 10^{14}$${\text{s}}^{-1}$ for PPy to $0.14\times 10^{14}$${\text{s}}^{-1}$ for PPy/8%CuO. The findings of this study offer empirical support for the possible use of PPy/CuO films in optical devices.

We present the results of extensive numerical integration in (1 +1) dimensions of a set of continuum equations which was recently proposed for describing the growth of thin composite solid films composed of two types of particles. In this model, the Kardar–Parisi–Zhang (KPZ) equation, which describes the growth of the films, is coupled to the time-dependent Ginzburg–Landau (TDGL) equation for the order parameter. We study the effect of the model's parameters on the universality of the scaling exponents that characterize the power-law behavior of the various properties of interest, and the transitions in the films' morphology that result from varying the parameters. We find that the scaling properties of the model are nonuniversal. Phase diagrams that identify the various scaling regimes, as well as the morphological transitions, are obtained. Thus, neither the dynamics of the domains' growth is governed by the TDGL equation, nor is the scaling of the films' surface structure described by the KPZ equation.

As a new nanomaterial, HgWO₄ nanofilms are prepared by the self-inventive technique of collodion nanoparticles-dispersal and film-formation. Their photoluminescent properties are enhanced and then controlled through nano-TiO₂ doping. These approaches not only ensure film uniformity and fluorescence (FL) enhancement, but also realize a FL increase/decrease conversion effect. The relationships between HgWO₄ nanofilms' PL intensities and TiO₂ doped amounts are in good agreement with Gaussion function, and maximum PL intensities of HgWO₄ nanofilms are located at 3.8% ratio of TiO₂ nanoparticles.

In this work, Ag nanoparticle/Ag-doped SiO₂ composite films were prepared with AgNO₃ and tetraethoxysilane precursors through a simple and environmentally friendly sol–gel method under high annealing temperatures. The effect of different annealing temperatures (400${}^{\circ }$C, 500${}^{\circ }$C, 600${}^{\circ }$C, and 700${}^{\circ }$C) on the structural and optical characters of the composite films was investigated. The localized surface plasmon resonance (LSPR) effect of the Ag nanoparticle/Ag-doped SiO₂ composite films enhanced the fluorescence intensity of CdSe quantum dots (QDs). Scanning electron microscopy (SEM), UV-vis spectrophotometer and photoluminescence (PL) spectroscopy were used to characterize the morphology and optical properties of the composite nanostructure.

In order to develop infinite capacitive materials with high dielectric constant and low dielectric loss, influences of Y/Mn co-doping and ZrO₂ coating on the dielectric properties of barium strontium tinanate/polyvinylidene fluoride (BST/PVDF) composite films were systematically investigated with fixing Y concentration as 0.3 at.% and varying Mn concentration from 1 at.% to 4 at.%. The experimental results show that the dielectric constant of BST@ZrO₂/PVDF composite increases by 50% relative to BST/PVDF and the dielectric loss is evidently depressed. In comparison with BST@ZrO₂/PVDF sample, furthermore, the dielectric constant of Y/Mn co-doped BST@ZrO₂/PVDF samples increases by about 60% and the dielectric loss further reduces at 1 kHz. The promoted dielectric performances of composite originate from the space charge separation formed by Y/Mn co-doping and the limitation of electronic mobility by coated ZrO₂. Y/Mn co-doped BST@ZrO₂/PVDF composite film with 3% Mn has a dielectric constant of 37.9, a dielectric loss of 0.0117, superior dielectric temperature stability (3.1% from −5${}^{\circ }$C to 45${}^{\circ }$C at 1 kHz), and a discharged energy density of 5.67 J/cm³ at 600 kV/cm. The simultaneous optimization of dielectric constant and dielectric loss of BST/PVDF composite is realized in this experiment. The superior dielectric temperature stability suggests the application potential of Y/Mn co-doped BST@ZrO₂/PVDF as wearable capacitors.