Composite particles consisting of polyaniline( PAn) core and barium tilanate ( BaTiO3) Layer shell were synthesized. The PAn-BaTiO3 composites particles were characterized with TEM and XRD. The dielectric behavior of ...
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Composite particles consisting of polyaniline( PAn) core and barium tilanate ( BaTiO3) Layer shell were synthesized. The PAn-BaTiO3 composites particles were characterized with TEM and XRD. The dielectric behavior of particles was tested and the electrorhcologicak(ER) behavior of the suspensions of PAn/ BaTiO3 panicles in chlorinated paraffin oil with a 20vol % was investigated under DC electric field. The results show that the ER effect of composite particle is far stronger than that of pure polyaniline and barium titanate which mere synthesized by the stone method. pH and thickness of BuTiO3 have an important. influence on the ER effects.
Nanocomposites offer a promising approach to the incorporation of nanostructured constituents into bulk thermo- electric materials. The 0.7-at% Bi-doped Mg2Si nanocomposites are prepared by spark plasma sintering of t...
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Nanocomposites offer a promising approach to the incorporation of nanostructured constituents into bulk thermo- electric materials. The 0.7-at% Bi-doped Mg2Si nanocomposites are prepared by spark plasma sintering of the mixture of nanoscale and microsized 0.7-at% Bi-doped Mg2Si powders. Microstructure analysis shows that the bulk material is composed of nano- and micrograins. Although the nanograin hinders electrical conduction, the nanocomposite struc- ture is more helpful to reduce thermal conductivity and increase the Seebeck coefficient, hence improving thermoelectric performance. A dimensionless figure of merit of 0.8 is obtained for the 0.7-at% Bi-doped Mg2Si nanocomposite with 50-wt % nanopowder, which is about twice larger than that of the sample without nanopowder.
Recently, the Pr-doped Ruddlesden-Popper phase of bilayer nickelate La3Ni2O7 has been reported to exhibit a superconducting transition temperature (Tc) of 82.5 K and superconducting volume fraction of about 57 % at hi...
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La0.1Ba0.9Fe12O19 powders with similar hexagonal crystal structure to Ba Fe12O19 have been successfully synthesized using polymer precursor method. The powders were suppressed into pellets, which were sintered into ce...
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La0.1Ba0.9Fe12O19 powders with similar hexagonal crystal structure to Ba Fe12O19 have been successfully synthesized using polymer precursor method. The powders were suppressed into pellets, which were sintered into ceramics at 1,300 °C for 1 h. The structure and morphology of the ceramics have been determined by X-ray diffraction(XRD) and field emission scanning electron microscopy(FESEM). Clear electric hysteresis loops upon different amplitude of external fields indicates that La0.1Ba0.9Fe12O19 is a kind of possible ferroelectric compound. The maximum remnant polarization of La0.1Ba0.9Fe12O19 ceramic is estimated to be *9.6 l C/cm2. The Fe O6 octahedron in its perovskite-like hexagonal unit cell as well as the shift of Fe3?off the center of octahedron are proposed to be the origin of electric polarization in La0.1Ba0.9Fe12O19. Simultaneous occurrence of large ferroelectricity and strong ferromagnetism has been observed in La0.1Ba0.9Fe12O19 ceramics. More interestingly, this compound demonstrates electronic polarization behavior being actuated by an applied magnetic field, indicating the existence of magnetoelectric(ME) coupling effect in the La0.1Ba0.9Fe12O19 ceramics. Our results may lead to new device applications such as magnetically recorded ferroelectric memory.
TiB_2 ceramics powder was synthesized from B_2O_3-TiO_2-Mg system. The effects of TiB_2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experimen...
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TiB_2 ceramics powder was synthesized from B_2O_3-TiO_2-Mg system. The effects of TiB_2 addition as diluent on the combustion synthesis process were investigated. The results of thermodynamic calculation and experiments show that the increase of TiB_2 content ranging from 0 to 20wt% can reduce the adiabatic temperature T_(ad) from 3100 K to 2896 K and combustion temperature T_c from 2139 K to 1621 K respectively. The particle size and half width of the particle distribution are also increased with the addition of TiB_2 increasing from 0 to 20wt%. The combustion product is a mixture of TiB_2, MgO, and other intermediate phases. The leached product contains mainly TiB_2, TiO_2 and TiN, and its oxygen content is 7.77wt%.
Improving thermal management materials is crucial for achieving multifunctional integrated applications and enhancing energy efficiency. Though phase change materials exhibit excellent thermal storage properties, the ...
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Great interests have arisen over the last decade in the development of hierarchically porous *** hierarchical structure enables materials to have maximum structural functions owing to enhanced accessibility and mass t...
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Great interests have arisen over the last decade in the development of hierarchically porous *** hierarchical structure enables materials to have maximum structural functions owing to enhanced accessibility and mass transport properties,leading to improved performances in various *** porous materials are in high demand for applications in catalysis,adsorption,separation,energy and *** the present review,recent advances in synthesis routes to hierarchically porous materials are reviewed together with their catalytic contributions.
The impact of trace V on the microstructure and mechanical characteristics of the Al-Zn-Mg-Cu alloy produced by twin-roll casting has been examined. Following homogenization, AlZnMgCu, S-Al2CuMg, and Al7Cu2Fe were amo...
The impact of trace V on the microstructure and mechanical characteristics of the Al-Zn-Mg-Cu alloy produced by twin-roll casting has been examined. Following homogenization, AlZnMgCu, S-Al2CuMg, and Al7Cu2Fe were among the primary phases that remained after the majority of the eutectic structure dissolved. The impact of dispersoids on the mechanical characteristics and intergranular corrosion resistance were examined, along with the precipitation behavior and recrystallization of Al3Zr and Al21V2 in the alloy. The hardness and yield strength of the V-containing alloy increase after homogenization, rolling, solution, and aging treatment. This enhancement may be attributed to the fine Al3Zr and Al21V2 particles’ precipitation strengthening, which augmented the traditional η′ phase precipitation strengthening. With the addition of V, the aging treatment alloy’s intergranular corrosion resistance was enhanced since there were fewer high-angle grain boundaries.
Porous functionalized silica nanoparticles have attracted the interest of researchers as they are excellent carriers for antibacterial drug delivery *** this work,porous aminated-silica nanoparticles(SiO2-NH2 NPs) wer...
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Porous functionalized silica nanoparticles have attracted the interest of researchers as they are excellent carriers for antibacterial drug delivery *** this work,porous aminated-silica nanoparticles(SiO2-NH2 NPs) were prepared via one-step approach through the ammonia-catalyzed hydrolysis of tetraethylorthosilicate(TEOS) and(3-aminopropyl) triethoxysilane(APTES) in a mixed water-ethanol *** obtained SiO2-NH2 NPs displayed a spherical morphology and relatively uniform size distribution,while the morphology and structure of SiO2-NH2 NPs were mainly determined by the order of the reagents added and the pH value of the *** characterization,the results showed that there were a large number of-NH2 groups on the surface of porous SiO2-NH2 NPs and that the porous SiO2-NH2 NPs had a large surface area of 476 m2 g-1 with an average pore width of 4.3 *** an absorbing-releasing experiment and bacterial test,those SiO2-NH2 NPs were found to exhibit efficient absorption and release of drugs as well as a pH-de pendent release pattern of epirubicin-loaded SiO2-NH2 ***,SiO2-NH2@capsaicin NPs exhibited antibacterial *** porous SiO2-NH2 NPs could be a candidate for drug delivery for antibacterial applications owing to their tailored porous structure and high surface area.
Silicon carbide ceramics with different thicknesses/diameter ratios were prepared by using ultra-fine silicon carbide powder with the sintering additives of 1.0 wt% boron and 1.5 wt% carbon. The influence of thickness...
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Silicon carbide ceramics with different thicknesses/diameter ratios were prepared by using ultra-fine silicon carbide powder with the sintering additives of 1.0 wt% boron and 1.5 wt% carbon. The influence of thickness/diameter ratio on the microstructure and density of SiC ceramics was investigated in detail. The experimental results show that the addition of boron and carbon sintering aids can promote the densification process of SiC ceramic, leading to the low sintering temperature and improve mechanical properties. At 1950 ℃, SiC ceramic with a density of 99% exhibits Young's modulus, hardness, and flexural strength of 476 MPa, 28.3 GPa, and 334 MPa, respectively. It is found that long holding time has a positive effect on the uniformity of the microstructure and density distribution of SiC ceramics with large thickness/diameter ratios. Additionally, the sintering additive of boron can solid-solve into SiC, and then facilitate the phase transformation of SiC to form 6H-SiC and 4H-SiC composite ceramics.
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