Molecular design of nanometric zinc borate-containing polyimide as a route to flame retardant materials

Zinc borate (Zn₂B₆O₁₁·3H₂O) nanoparticles were successfully prepared by using an emulsion liquid membrane (W/O/W emulsion) to control the size of particles with Na₂B₄O₇·10H₂O, boric acid and ZnSO₄·7H₂O as raw materials. All materials were dispersed with the polyimide (PI) precursor, poly (amic acid). Using a combination of dissolving the poly (amic acid) and mixing fatty acid surfactant-coated zinc borate nanoparticles; we have demonstrated the formation of nanocomposites with uniform nanoparticles dispersion. We report the first deposition of nanocomposite polyimides from solution using spin-coating. The microstructures and morphology of the as-obtained samples were studied by X-ray diffraction (XRD), infrared spectra (IR), scanning electron microscopy (SEM) equipped with an energy-dispersive X-ray spectrometer (EDX), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA).     

Rapid fabrication and optical properties of zinc sulfide nanocrystallines in a heterogeneous system

ZnS nanoparticles about 3 nm in size were prepared by a simple, rapid and reliable route under microwave irradiation in a heterogeneous system, using ZnAc₂·2H₂O (AcCH₃COO) and Na₂S·9H₂O as the starting materials, ethylene glycol (EG) as the medium. The product was characterized with X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and ED, respectively. The optical properties of ZnS nanoparticles were studied.     

Fabrication of ultrafine tungsten-based alloy powders by novel soda reduction process

A novel reduction method has been developed to fabricate ultrafine tungsten heavy alloy powders, with ammonium metatungstate (AMT), iron(II) chloride tetrahydrate (FeCl₂·4H₂O), nickel(II) chloride hexahydrate (NiCl₂·6H₂O) as source materials and sodium tungstate dihydrate (Na₂WO₄·2H₂O) as a reductant. In the preparation of mixtures the amounts of the source components were chosen so as to obtain alloy of 93W-5Ni-2Fe composition (wt.%). The obtained powders were characterized by X-ray diffraction, XPS, field-emission scanning microscope (FESEM), and chemical composition was analyzed by EDX.     

Preparation and characterization of CuO nanorods by thermal decomposition of CuC2O4 precursor

Synthesis of copper oxide (CuO) nanorods was achieved by thermal decomposition of the precursor of CuC₂O₄ obtained via chemical reaction between Cu(CH₃COO)₂·H₂O and H₂C₂O₄·2H₂O in the presence of surfactant nonyl phenyl ether (9)/(5) (NP-9/5) and NaCl flux. Transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), selected-area electron diffraction (SAED) and high-resolution TEM (HRTEM) were used to characterize the structure features and chemical compositions of the as-made nanorods. The results showed that the as-prepared nanorods is composed of CuO with diameter of 30-100 nm, and lengths ranging from 1 to 3 μm. The mechanism of formation of CuO nanorods was also discussed.     

Size and morphology-controlled Ni2[Fe(CN)6]·xH2O Prussian Blue analogue fabricated via a hydrothermal route

Nanocrystalline Prussian Blue analogue Ni₂[Fe(CN)₆]·xH₂O was synthesized through hydrothermal process at 180 °C for 24 h with NiSO₄·6H₂O and K₄[Fe(CN)₆]·3H₂O as precursors. The effects of reactant concentration and protective matrix (Polyethylene glycol 400, PEG-400) on the size and morphology of nanoparticles were investigated. The as-synthesized products were identified as face-centered cubic structure by powder X-ray diffraction. Field-emission scanning electron microscopy and transmission electron microscopy images showed that well dispersed nanoparticles with fairly narrow size distribution were successfully prepared.     

Microemulsion-mediated solvothermal synthesis of tin(IV) hydrogen phosphate rose-like three-dimensional nanostructures and their electrochemical properties

Novel rose-like three-dimensional Sn(HPO₄)₂·H₂O nanostructures self-assembled by tightly stacked nanopetals were successfully synthesized by a simple cetyltrimethylammonium bromide (CTAB)/water/cyclohexane/n-pentanol microemulsion system under solvothermal conditions for the first time. A series of compared experiments were carried out to investigate the factors that influence the morphology and size of the products. It was found that the molar ratio of water to CTAB and the concentration of SnCl₄ aqueous solution play important roles in the formation of the rose-like nanostructures. A possible formation mechanism of rose-like nanostructures was proposed, which may be related to the crystal structure of Sn(HPO₄)₂·H₂O and the spherical micelles formed by the microemulsion. The electrochemical properties of Sn(HPO₄)₂·H₂O were investigated through cyclic voltammetry (CV) measurements. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and field-emission scanning electron microscope (FE-SEM) were used to characterize the products.     

Reaction of π-Ti2O(PO4)2·2H2O with molten alkali nitrates: Synthesis of the fibrous materials π-M0.5H0.5TiOPO4 (M = Na, K)

Powder X-ray diffraction data for π-Ti₂O(PO₄)₂·2H₂O (π-TiP) is indexed in a monoclinic cell [a=5.067(4), b=10.898(3), c=14.533(8) Å, β=96.0(1)°]. Structural correlations with other titanium phosphates are discussed. The reaction of π-TiP with molten MNO₃ (M=Na, K) originates new metal phases with a KTP-type formula, π-M_0.5H_0.5TiOPO₄. These compounds maintain the fibrous morphology of their precursor. The reactions are monitored by thermogravimetric analysis. Thermal decomposition of the novel compounds is described.     

Synthesis and regulation of α-LiZnPO4·H2O via a solid-state reaction at low-heating temperatures

A simple and novel route for the synthesis of a lithium zinc phosphate hydrate, α-LiZnPO₄·H₂O, was studied, and the target product was obtained with LiH₂PO₄·H₂O and ZnCO₃ as raw materials and polyethylene glycol-400 (PEG-400) as a surfactant via a one step solid-state reaction at room temperature (25 °C). The product was characterized with X-ray powder diffraction (XRD), thermogravimetric analysis and the 1st derivativative of thermogravimetric analysis (TG/DTG) and Fourier transform infrared spectroscopy (FTIR). The comparison experimental results suggested that aging temperature controlled the products of the synthesis, that is, the α-LiZnPO₄·H₂O was formed when the reaction mixture was aged at room temperature, and the α-LiZnPO₄ was obtained when the reaction mixture was aged at 80 °C.     

Microemulsion-assisted solvothermal synthesis of Nd2(CO3)3·8H2O microstructures

Microstructures of Nd₂(CO₃)₃·8H₂O with various morphological structures and sizes were successfully synthesized using the microemulsion-assisted solvothermal method. The obtained products were characterized by X-ray diffraction (XRD), differential scanning calorimetry and thermal gravimetric analysis (DSC-TGA), scanning electron microscope (SEM), transmission electron microscope (TEM) and electron diffraction (ED). The results showed that pyramid-like and spherical Nd₂(CO₃)₃·8H₂O microstructures were synthesized depending on the reaction time and reaction temperature. Moreover, the reaction time and temperature also played important roles in controlling the morphologies and sizes of the resulting Nd₂(CO₃)₃·8H₂O microstructures.     

Synthesis of hierarchical Ni11(HPO3)8(OH)6 superstructures based on nanorods through a soft hydrothermal route

In this paper, we reported the successful synthesis of hierarchical Ni₁₁(HPO₃)₈(OH)₆ superstructures based on nanorods via a facile hydrothermal route, employing NiCl₂·6H₂O and NaH₂PO₂·H₂O as the reactants in the presences of polyvinylpyrrolidone (PVP) and CH₃COONa·3H₂O. The reaction was carried out at 170 °C for 10 h. HPO₃²⁻ ions were provided via the dismutation reaction of H₂PO₂⁻ ions in a weak basic solution. The as-obtained products were characterized by X-ray powder diffraction (XRD), energy dispersive spectrometry (EDS), field emission scanning electron microscopy (SEM), selected area electron diffraction (SAED) and high resolution transmission electron microscopy (HRTEM). Some factors influencing the morphology of the hierarchical Ni₁₁(HPO₃)₈(OH)₆ nanorods, such as the reaction temperature, time, the amounts of PVP and CH₃COONa, and the initial concentration of Ni²⁺ ions, were systematically investigated. A possible growth mechanism was proposed based on experimental results.