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Herein, we are reporting the synthesis of polythiophene, polypyrrole, and reinforced nickel oxide (NiO) hybrid nanocomposites by an in-situ chemical oxidative polymerization of thiophene and pyrrole in the presence of NiO nanoparticles. The polymerized nanocomposites were thoroughly characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) studies, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The concentration of polymer-NiO hybrids varied between different ratios of PTh, PPy and NiO contents. A maximum dielectric constant of ≈ 1×106 was observed at a higher ratio of polymer-filler contents. The PTh-PPy-NiO hybrid nanocomposite structure and crystallinity were verified by X-ray diffraction (XRD), and the FTIR approach demonstrated a robust interaction between PTh, PPy, and NiO particles. The surface morphology analysis revealed that NiO particles were successfully integrated with PTh, PPy during the polymerization process by forming a network. The dielectric constant values of the resultant nanocomposites were obtained from capacitance measurements. The dielectric constant for the higher concentration ratio of polymer-NiO hybrids was much higher than that of the pristine PTh, PPy matrix. A significant increase in dielectric loss and AC conductivity was observed for the higher concentration of PTh-PPy-NiO ternary nanocomposites. These PTh-PPy-NiO hybrid nanocomposites can potentially be useful in developing high-performance composite materials in the electronic field. Herein, we are reporting the synthesis of polythiophene, polypyrrole, and reinforced nickel oxide (NiO) hybrid nanocomposites by an in-situ chemical oxidative polymerization of thiophene and pyrrole in the presence of NiO nanoparticles. The concentration of polymer-NiO hybrids varied between different ratios of PTh, PPy, and NiO contents. A maximum dielectric constant of ≈ 1×106 was observed at a higher ratio of polymer-filler contents. The dielectric constant for the higher concentration ratio of polymer-NiO hybrids was much higher than that of the pristine PTh, PPy matrix. A significant increase in dielectric loss and AC conductivity was observed for the higher concentration of PTh-PPy-NiO ternary nanocomposites. These PTh-PPy-NiO hybrid nanocomposites can potentially help develop high-performance composite materials in the electronic field. [ABSTRACT FROM AUTHOR]

Cefuroxime axetil is a significantly used in drug formulation. Therefore, this study aimed to prepare a nanosuspension of cefuroxime axetil, a poorly water-soluble drug, using an antisolvent precipitation method, followed by ultrasonication. A 32 factorial design was used, and the effects of stirring speed (X1) and poloxamer 188 concentration (X2) on the particle size (Y1) and entrapment efficiency (Y2; %EE) of the prepared nanosuspension were investigated. The nanoparticles were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR), powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), and zeta potential analysis. The bioavailability of the formulation was assessed in rats. The results indicated that increasing the stirring speed and reducing the poloxamer concentration decreased the size of the nanoparticles. The optimized formulation showed particle size and zeta potential of 170 nm and − 31.3 mV, respectively. FTIR analysis revealed no incompatibilities between the formulation components. XRD and DSC analyses confirmed the amorphization of cefuroxime axetil in the nanosuspension. The developed nanoformulation showed 10.98-fold improvement in the oral bioavailability of cefuroxime axetil. The anti-solvent precipitation process successfully produced a stable amorphous nanosuspension with a notably reduced particle size and improved bioavailability by evaluating and optimizing the critical process and formulation parameters. [ABSTRACT FROM AUTHOR]

The tri-phase PMMA-NaNbO3-CQD composite films consisting of surface hydroxylated sodium niobate and carbon quantum dots as functional filler particles and poly (methyl methacrylate) (PMMA) as polymer matrix were prepared by solution casting technique. The structural, morphological, dielectric, and electric characteristics of tri-phase PMMA-NN-CQD composites at various CQD weight percentages were investigated as a function of frequency. The dielectric characteristics of the PMMA-h-NN-CQD composites exhibit a higher dielectric constant (≈107) and considerably reduced dielectric loss (≈1) at 102 Hz, which is 26 times greater than that of the neat polymer matrix. Furthermore, the PMMA-h-NN-CQD composite demonstrated decreased dielectric loss and higher a.c conductivity. SEM analyses show that the CQD particles were effectively integrated inside the NaNbO3 particles to boost the composite films' homogeneity, which in turn improved the dielectric and electrical characteristics of the composite films. Our strategy provides a novel method for producing tri-phase PMMA-h-NN-CQD composite films with excellent dielectric and electrical performance for high energy storage dielectric applications. [ABSTRACT FROM AUTHOR]

Graphene oxide-based materials are well known for their electrical properties. Novel ternary composite films (PVDF-GO-FK-31) were prepared by introducing a metal complex, for the first time, in a graphene oxide-PVDF polymer matrix (where PVDF = polyvinylidene fluoride; GO = graphene oxide; FK-31 = [Ni(PPh3)2(SCOf)2] (SCOf = furan-2-thiocarboxylate). In these composites, the graphene oxides show strong interfacial bonding with the PVDF matrix due to the incorporation of the FK-31 molecules. The experimental results showed that the incorporation of FK-31 into the PVDF-GO matrix greatly improved the dielectric constant and suppressed dielectric loss values. The composites thus may be used as dielectric materials for electronic capacitors. For the first time, a ternary composite was prepared by incorporating a newly synthesized square planar nickel(II) complex in a graphene oxide-PVDF polymer matrix and its dielectric and electric properties were studied. With increasing concentration of the complex in the ternary composite its dielectric constant and electrical conductivity increases while the dielectric loss decreases. [ABSTRACT FROM AUTHOR]

PA-KNNT-P(VDF-HFP) composite films were synthesized using facile solution casting technique. Due to their wide range of applications in dielectric and electrical systems, phosphonic acid (PA)-modified tantalum-doped potassium sodium niobate (KNNT)–polyvinylidene fluoride co-hexafluoropropylene P(VDF-HFP) composite films have piqued the interest of academic researchers. Microstructural analysis showed that PA layers incorporated onto the KNNT particles within the polymer matrix. The PA-KNNT-P(VDF-HFP) composite exhibited improved dielectric and electrical performance over a broad range of frequency, and the value of the dielectric constant of the P(VDF-HFP) composites is improved by ≈119 over the P(VDF-HFP) matrix at a filler loading 19 wt.%. Moreover, PA-KNNT-P(VDF-HFP) composite also reveals higher dielectric constant (≈ 119) and AC conductivity than P(VDF-HFP)-KNNT composites, while maintaining suppressed dielectric loss ( ≤ 1.3 at 102 Hz). It is also observed that the PA-KNNT-P(VDF-HFP) composite exhibited an insulator–conductor transition with a percolation threshold of fKNNT = 13.4 wt.%. As a result of their exceptional dielectric and electrical characteristics, PA-KNNT-P(VDF-HFP) composites have the potential to find exciting practical applications in a variety of electronic domains. [ABSTRACT FROM AUTHOR]

Three-component PMMA–NaNbO3–starch percolative composites with starch and sodium niobate (NaNbO3; NN) particles embedded into poly(methylmethacrylate) (PMMA) matrix were prepared using solution casting technique. The structure, dielectric and electrical properties of the three-component PMMA–NN–starch composites containing starch in (PMMA + NaNbO3) matrix as function of frequency and the different weight percentages of starch were employed. The experimental results showed that the three-component PMMA–NN–starch composite has a superior dielectric constant (≈395) and suppressed dielectric loss (< 0.6) at 100 Hz. Moreover, the improvement of electrical properties of the composites may be attributed to the synergistic effect of the NN ceramics and conductive starch particles within the polymer matrix. The homogeneous dispersion gives an insulating layer between neighboring conductive starch particles in the PMMA matrix, which not only prevent the direct contact of starch but also provides with better homogeneity of the starch particles in the composite system. Furthermore, the percolation theory is utilized to elucidate the dielectric and electrical performance of the composite. These three-component PMMA–NN–starch composite exhibited an insulator–conductor transition with 7 wt% of starch contents at percolation threshold. This work might be a new approach to produce excellent composite films with enhanced dielectric and electrical properties for high performance energy storage applications. [ABSTRACT FROM AUTHOR]

A tri-phase polymer composite film with a multiferroic phase (BiFeO3) and conductive carbon black (CB) deposited on the BiFeO3 (BF) and poly(vinylidene fluoride) (PVDF) matrix were prepared by using a solution casting technique. The dielectric and electrical performance of BF–PVDF composites with various weight percentages of CB content was studied. It has been observed that the incorporation of high loading of CB to the BF–PVDF composite system led to a significant improvement in the dielectric constant with suppressed dielectric loss (< 0.5). The high dielectric constant of 69 at 100 Hz, which is 11 times greater than that of neat PVDF film with a lower dielectric loss of 0.41, is obtained for PVDF–BF–CB composites as CB content (8 wt%) approached the percolation threshold. Furthermore, the improvement of dielectric and electrical performance of the PVDF–BF–CB composites may be due to the synergistic effect of the multiferroic phase BF and conductive phase CB as a result of homogeneous dispersion within the polymer matrix. These high dielectric constant and suppressed dielectric loss PVDF–BF–CB composites might be suitable for potential applications in the field of future thin-film capacitors. [ABSTRACT FROM AUTHOR]

Hydroxylated barium titanate (BaTiO3; h-BT) particles have been synthesized by aqueous solution of hydrogen peroxide (H2O2), then modified hydroxylated barium titanate (BaTiO3; h-BT) particles were synthesized by aqueous solution of hydrogen peroxide (H2O2) followed by modification with bis(2-ethylhexyl) sulfosuccinate sodium salt (h-BT@AOT) to form h-BT@AOT-poly(vinylidene fluoride) (PVDF) composites via a solution casting technique. Fourier-transform infrared spectroscopy, scanning electron microscopy, and dielectric and electrical measurements using an impedance analyzer were applied to understand the effect of AOT on the dielectric and electrical performance of the composites. The dielectric constant of the composites including modified ceramic particles (h-BT@AOT) increased remarkably with increasing filler content. The results showed that the h-BT@AOT particles were well dispersed in the polymer matrix. The dielectric constant of the composites with 12 wt.% h-BT@AOT was as high as ∼ 120 at 100 Hz at the percolation threshold, being nearly 19 times higher than that of the PVDF matrix. Moreover, the dielectric loss of the composites was negligible (< 0.5) as compared with pure h-BT. Thus, this method for fabrication of h-BT@AOT provides a larger interface area for binding the matrix with the modified ceramic particles via electrostatic interactions. Hence, AOT has a significant interfacial impact, being responsible for the enhancement of the dielectric properties and possibly useful in the field of energy storage devices as compared with pure h-BT. [ABSTRACT FROM AUTHOR]

In today's world, technology for capacitor applications have rapidly increased the interest for the development of perfect composite materials (polymers and ceramics) with enhanced dielectric properties. In the present work, the composites with bismuth ferrite (BiFeO3, BFO) particles as functional fillers and polystyrene (PS) as polymer matrix was prepared by solution casting technique. To improve the dielectric properties of the composites, the surface of BFO particles were chemically treated with H2O2 to introduce –OH groups. The experimental results show that the hydroxylated BFO-PS composites enhanced the dielectric constant, AC electrical conductivity and the dielectric loss is relatively suppressed. The surface hydroxylated BFO particles were more homogeneously dispersed into the PS matrix and it was confirmed by scanning electron microscopy (SEM). Moreover, the ferroelectric properties of the composites were significantly improved and a maximum remnant polarization (2Pr = 1.442 μC/cm2) was obtained in the composite materials as compared with BFO-PS at the same volume fraction of fillers. The thermal properties of the resultant composite films were investigated by using differential scanning calorimetry (DSC) method. The demonstrated approach may provide a route for using the hydroxylated ceramics to enhance the dielectric properties in ceramic-based polymer composites. [ABSTRACT FROM AUTHOR]

Abstract: Surface modification plays an important role to enhance the dielectric constant and minimize the dielectric loss. In this study, poly(methyl methacrylate) (PMMA) composites filled with 2-aminoethanesulfonic acid-modified bismuth ferrite (BiFeO3; BFO) have been prepared via solution casting technique. The surface morphology of the composites provides a better homogeneous dispersion of the particles in the polymer matrix and increases interface compatibility between modified BFO and PMMA matrix. The experimental results show that the composites have high dielectric constant (≈ 147), alternating current (AC) conductivity (1 × 10−5) and relatively low loss (< 1) at 100 Hz. The percolation phenomenon is well observed in the composite having less than 30 wt.% of BFO particles. Further, the composites produce passivation layers on the surface of modified BFO particles which might improve the morphology and promote the space charges, interface effects and dielectric properties. Our strategy is to provide a simple and efficient approach to fabricate high-performance dielectric composites for energy storage applications.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Three-phase nanocomposite films, made up of polystyrene (PS), bismuth ferrite (BiFeO; BFO) and conducting particles of graphite nanopowder (GNP), were prepared by solution casting techniques. Using different volume fractions of GNP, the dielectric properties of the nanocomposites were analyzed by impedance analyzer with various ranges of electric fields. To support our discussions, percolation theory was used to know the dielectric behavior of the PS-BFO-GNP nanocomposites and the percolation threshold was observed at 3 vol% of GNP. The dielectric constant of PS-BFO-GNP nanocomposites reached as high as ~75 at 0.1 kHz, which was much higher than that of pure PS, PS-BFO and PS-GNP nanocomposites. Furthermore, the P-E hysteresis loop study was carried out to observe the ferroelectric behavior of the nanocomposites. [ABSTRACT FROM AUTHOR]

To improve the compatibility between the ceramic particle and polymer matrix, the surface modifier polyethylene glycol (PEG) was used for the modification of BaTiO (BT) particles as fillers in the poly(vinylidene fluoride) (PVDF) matrix via solution casting techniques. The structural analysis of the composite characterized by X-ray diffraction confirms the tetragonal structure. The results showed that the PEG modified BT-PVDF composites had a higher dielectric constant (≈192) and relatively lower dielectric loss value at 1000 Hz. The Nyquist plot suggests the contribution of only bulk effect present in the composites. The AC electrical conductivity studies obey Jonscher's universal power law by fitting AC conductivity data which reveals the potential utility of the composites for ideal capacitor and microscopic reasons for this improvement were presented. Furthermore, the remnant polarization was significantly improved and maximum polarization was observed for PEG modified BT-PVDF composites. [ABSTRACT FROM AUTHOR]

A novel two-phase composite film is prepared by the solvent casting method employing poly(methyl methacrylate) (PMMA) as polymer matrix and bismuth ferrite (BFO) as ceramic filler. The surfaces of BFO are functionalized by proper hydroxylating agents to activate their chemical nature. The structural analysis of the composite films confirms that the composites made up of functionalized BFO (BFO-OH) have a distorted rhombohedral structure. The morphological analysis shows that BFO-OH particles are equally distributed over the polymer matrix. The -OH functionality of BFO-OH is confirmed by FTIR. The dielectric and electrical studies at a frequency range from 100 Hz to 1 MHz reveal that PMMA-(BFO-OH) composites have enhanced dielectric constant as well as electrical conductivities, much higher than that of unmodified composites. According to the ferroelectric measurement result, the hydroxylated composite film shows a superior ferroelectric behavior than that of the unmodified one, with a remanent polarization (2 P ) of 2.764 μC/cm. [ABSTRACT FROM AUTHOR]