Shouhu Xuan

Bio: Shouhu Xuan is an academic researcher from University of Science and Technology of China. The author has contributed to research in topics: Magnetorheological fluid & Superparamagnetism. The author has an hindex of 25, co-authored 31 publications receiving 3144 citations. Previous affiliations of Shouhu Xuan include Hong Kong Baptist University & The Chinese University of Hong Kong.

Tuning the Grain Size and Particle Size of Superparamagnetic Fe3O4 Microparticles

Abstract: Secondary structural, superparamagnetic Fe3O4 microparticles with an average diameter of 280 nm have been successfully synthesized by using a one-step hydrothermal method. The size of the primary nanograins has been controlled from 5.9 to 21.5 nm by varying the sodium acrylate/sodium acetate weight ratios. The magnetic properties of the Fe3O4 microparticles have been characterized at room temperature, whereas the saturation magnetization values of the Fe3O4 microparticles increase with increasing grain sizes. Magnetic resonance imaging reveals that Fe3O4 microparticle with larger grain size yields higher molar T2 relaxation rate. A plausible growth mechanism of the particles is proposed, and the role of sodium acrylate and sodium acetate for tuning the grain size of the particles has been discussed. Additionally, the size of the secondary structural Fe3O4 particles can also be continuously controlled from 6 to 170 nm by varying the volume ratio of ethylene glycol/diethylene glycol in a bisolvent system. T...

Preparation, characterization, and catalytic activity of core/shell Fe3O4@polyaniline@au nanocomposites.

Abstract: We report a new method to synthesize magnetically responsive Fe3O4@polyaniline@Au nanocomposites. The superparamagnetic Fe3O4@polyaniline with well-defined core/shell nanostructure has been synthesized via an ultrasound-assisted in situ surface polymerization method. The negatively charged Au nanoparticles with a diameter of about 4 nm have been effectively assembled onto the positively charged surface of the as-synthesized Fe3O4@polyaniline core/shell microspheres via electrostatic attraction. The morphology, phase composition, and crystallinity of the as-prepared nanocomposites have been characterized by transmission electron microscopy (TEM) and powder X-ray diffraction (XRD). The central Fe3O4 cores are superparamagnetic at room temperature with strong magnetic response to externally applied magnetic field, thus providing a convenient means for separating the nanocomposite from solution. As-prepared inorganic/organic nanocomposite can be used as a magnetically recoverable nanocatalyst for the reduction of a selected substrate.

Magnetically Separable Fe3O4/TiO2 Hollow Spheres: Fabrication and Photocatalytic Activity

Abstract: Well-defined magnetic separable, hollow spherical Fe3O4/TiO2 hybrid photocatalysts were successfully prepared through a poly(styrene−acrylic acid) (PSA) template method. This bifunctional product was characterized in terms of the particle size, surface morphology, chemical composition, and magnetic properties using transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), and X-ray powder diffraction (XRD) patterns. The M−H hysteresis loop for Fe3O4/TiO2 hollow spheres indicates that the composite spheres show superparamagnetic characteristics at room temperature. These magnetic TiO2 composites with hollow nature exhibit good photocatalytic activity under UV light irradiation and can be recycled six times by magnetic separation without major loss of activity. This method can be further applied to synthesize other bifunctional hollow spheres, such as Fe3O4/SnO2 and Fe3O4/CdS.

Gold and iron oxide hybrid nanocomposite materials

Abstract: This critical review provides an overview of current research activities that focused on the synthesis and application of multi-functional gold and iron oxide (Au–FexOy) hybrid nanoparticles and nanocomposites An introduction of synthetic strategies that have been developed for generating Au–FexOy nanocomposites with different nanostructures is presented Surface functionalisation and bioconjugation of these hybrid nanoparticles and nanocomposites are also reviewed A variety of applications such as theranostics, gene delivery, biosensing, cell sorting, bio-separation, and catalysis is discussed and highlighted Finally, future trends and perspectives of these sophisticated nanocomposites are outlined Underpinning the fundamental requirements for effectively forming Au–FexOy hybrid nanocomposite materials would shed light on future development of nanotheranostics, nanomedicines, and chemical technologies It would be interesting to investigate such multi-component composite nanomaterials with different novel morphologies in the near future to advance chemistry, biology, medicine, and engineering multi-disciplinary research (120 references)

Synthesis of biocompatible, mesoporous Fe(3)O(4) nano/microspheres with large surface area for magnetic resonance imaging and therapeutic applications.

Abstract: This article reports the fabrication of mesoporous Fe(3)O(4) nano/microspheres with a high surface area value (163 m(2)/g, Brunauer-Emmett-Teller) and demonstrates their use for drug loading, release, and magnetic resonance imaging (MRI). These monodispersed, mesoporous Fe(3)O(4) nano/microspheres with controllable average sizes ranging from 50 to 200 nm were synthesized using a Fe(3)O(4)/poly(acrylic acid) hybrid sphere template and subsequent silica shell formation and removal. We found that the SiO(2) coating is a crucial step for the successful synthesis of uniform mesoporous Fe(3)O(4) nano/microspheres. The as-synthesized mesoporous Fe(3)O(4) nanospheres show a high magnetic saturation value (M(s) = 48.6 emu/g) and could be used as MRI contrast agents (r(2) = 36.3 s(-1) mM(-1)). Trypan blue exclusion and MTT assay (see Supporting Information ) cytotoxicity analyses of the nanospheres based on HepG2 and MDCK cells showed that the products were biocompatible, with a lower toxicity than lipofectamine (positive control). Hydrophilic ibuprofen and hydrophobic zinc(II) phthalocyanine drug loading into mesoporous Fe(3)O(4) nanospheres and selected release experiments were successfully achieved. The potential use of mesoporous Fe(3)O(4) nanospheres in biomedical applications, in light of the nano/microspheres' efficient drug loading and release, MRI, and low cytotoxicity, has been demonstrated. It is envisaged that mesoporous Fe(3)O(4) nanospheres can be used as drug carriers and MRI contrast agents for the reticuloendothelial system; they can also be delivered locally, such as via a selective catheter.

Magnetically recoverable nanocatalysts.

Abstract: We gratefully acknowledge funding and support from King Abdullah University of Science and Technology (KAUST). Thanks are also due to the KAUST communication department for designing several images for this Review.

Magnetically Separable Nanocatalysts: Bridges between Homogeneous and Heterogeneous Catalysis

Abstract: Recovery and reuse of expensive catalysts after catalytic reactions are important factors for sustainable process management. The aim of this Review is to highlight the progress in the formation and catalytic applications of magnetic nanoparticles and magnetic nanocomposites. Directed functionalization of the surfaces of nanosized magnetic materials is an elegant way to bridge the gap between heterogeneous and homogeneous catalysis. The introduction of magnetic nanoparticles in a variety of solid matrices allows the combination of well-known procedures for catalyst heterogenization with techniques for magnetic separation.