Zuyao Chen

Preparation and thermal properties of ABS/montmorillonite nanocomposite

Acrylonitrile-butadiene-styrene (ABS)/clay nanocomposite (nanoABS) has been prepared using a direct melt intercalation technique. Its structure and thermal properties are characterized by XRD, HTEM and TGA. The results of HTEM show that nanoABS is a kind of intercalated-delaminated structure. The nanocomposite enhances the formation of char and improves the thermal stability of ABS matrix as measured by TGA.

A facile method to fabricate carbon-encapsulated Fe3O4 core/shell composites

One-step synthesis of carbon-encapsulated Fe(3)O(4) core/shell composites is reported. The Fe(3)O(4) cores were formed via the reduction of Fe(3+) by glucose under alkaline conditions obtained by the decomposition of urea. The amorphous carbon shells were carbonized from glucose. A possible formation mechanism for the Fe(3)O(4)@C composite was discussed. In order to characterize these Fe(3)O(4)@C core-shell composites, high-resolution transmission electron microscopy (HR-TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), x-ray photoelectron spectroscopy (XPS) and a superconducting quantum interference device (SQUID) magnetometer were employed to characterize the sample obtained using the above method.

Preparation and thermal stability of polypropylene/montmorillonite nanocomposites

Two different methods were used to prepare polypropylene/clay nanocomposites. One was from pristine montmorillonite and a reactive compatibilizer hexadecyl trimethyl ammonium bromide (C6); the other is from different organophilic montmorillonites (OMT). The nanocomposites structures are demonstrated by X-ray diffraction (XRD) and transmission electron microscopy (TEM); The thermal properties of the nanocomposites were investigated by thermogravimetric analysis (TGA). It is shown that different methods and organophilic montmorillonites influence the morphology and thermal stability of polypropylene/clay nanocomposites.

Fabrication of silica core–conductive polymer polypyrrole shell composite particles and polypyrrole capsule on monodispersed silica templates

Abstract Silica core–polypyrrole shell composite particles were fabricated by chemical polymerization of pyrrole monomer on the surface of the silica spheres. The steric agent poly( N -vinylpyrrolidone) (PVP) was used as anchor-molecule between core and polymer monomer during the polymerization. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show that the polypyrrole (PPy) shell is uniformly coated over the silica surface. Furthermore, conductive polypyrrole hollow capsules were obtained after the removal of the core. In addition, the macromolecule PVP was retained in the capsules detected by UV-Vis spectra. The size of the core–shell particles and the thickness of the capsules are dependent on the size of silica template as well as the weight ratio of [silica spheres template]/[pyrrole monomer].

Synthesis and characterization of polycarbonate/ABS/montmorillonite nanocomposites

Abstract Polycarbonate (PC)/acrylonitrile-butadiene-styrene (ABS) polymer alloy/montmorillonite (MMT) nanocomposites have been prepared by direct melt intercalation. Their structure and thermal properties are characterized by XRD, TEM, HREM and TGA. The results of XRD and HREM show that nanocomposite is a kind of intercalated structure and the gallery heights of PC/ABS/MMT nanocomposites are almost the same as that of PC/MMT nanocomposite, 3 nm; meanwhile, the nanocomposites improves the thermal stability of PC/ABS polymer alloy matrix.

Thermal analysis of poly(vinyl alcohol)/graphite oxide intercalated composites

Poly(vinyl alcohol)/graphite oxide intercalated nanocomposites have been prepared and characterized by X-ray diffraction. Their differential scanning calorimetry and thermogravimetry results suggest that the content of graphite oxide change the glass transition temperature of nanocomposites, and the increase of graphite oxide content can cause the increase of the oxidation temperature of nanocomposites and decrease of their mass loss rate.

Preparation and flammability properties of polyethylene/clay nanocomposites by melt intercalation method from Na + montmorillonite

Abstract Polyethylene (PE)/clay composites have been prepared by melt intercalation technique direct from Na + montmorillonite (MMT) while using hexadecyl trimethyl ammonium bromide (C16) as reactive compatibilizer. Their degree of dispersion and intercalation spacings, as determined by X-ray diffraction (XRD), were typical of either a microcomposite or an intercalated nanocomposite, depending on the content of C16 in composites. Combustion experiments showed that the microcomposite burns in the same way as pure PE, whereas the heat release rate (HRR) is reduced by 32% when nanocomposite is with low silicate loading (5 wt.%) and C16 loading (4 wt.%).

Preparation and characterization of polystyrene/graphite oxide nanocomposite by emulsion polymerization

Polystyrene intercalated graphite oxide (GO) nanocomposite was prepared by emulsion polymerization reaction and characterized by X-ray diffraction (XRD), high resolution electron microscopy (HREM), and thermogravimetric analysis (TGA). It was shown that polystyrene can be intercalated into the interlayer space of GO and form exfoliated and intercalated nanocomposites. The thermal analysis demonstrated that the presence of GO enhances the char residue of the nanocomposite.

Preparation of the poly(vinyl alcohol)/layered double hydroxide nanocomposite

Intercalated nanocomposite based on Mg, Al layered double hydroxide (LDH) and poly(vinyl alcohol) (PVA) was prepared using exfoliation-adsorption technique, and characterized by X-ray diffraction and thermal gravimetric analysis. The results suggest that the intercalated species are formed via the re-aggregation of the delaminated LDH lamellar with the interlayer spacing 14.5 A, and the thermal stability of the nanocomposite improved compared with the original PVA.

Preparation and characterization of nanocrystalline powders of cuprous oxide by using γ-radiation

Abstract The γ-radiation method has been firstly used to prepare nanocrystalline powders of cuprous oxide from cupric sulfate aqueous solution in the presence of CH 3 COOH CH 3 COONa buffer pair. X-ray powder diffraction reveals that the product is single phase of cuprous oxide. Electron microscopy shows that the average particle size of cuprous oxide prepared is about 14 nm. Influences of experimental conditions on particle size of cuprous oxide and the mechanism of the formation of cuprous oxide are discussed.