Ruibin Guo

Preparation and Characterization of Graphene/Europium Oxide Composites

Eu2O3/graphene nanocomposites have been synthesized using graphite oxide and europium nitrate as precursor for graphene and europium oxide, respectively. Graphene coated by nanosized Eu2O3 particles has been confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis. TEM analysis images illustrated that the as-formed Eu2O3 nanoparticles were densely and uniformly deposited on the graphene nanosheets. The good distribution of Eu2O3 nanoparticles on graphene nanosheets improved the thermal stability of Eu2O3/graphene namocomposites. A plausible mechanism for formation of the intriguing nanocomposite has been proposed. Moreover, Eu2O3/graphene nanocomposites exhibited both optical and electrical properties. These Eu2O3/graphene nanocomposites show potential applications in electronic and optoelectronic systems.

Fabrication of Polyaniline/Graphene/Tb3+ Conductive Composite Material

Polyaniline/graphene/Tb3+(PANI/GN/Tb3+) composite material was successfully prepared by the method of in-situ polymerization. The morphology of this as-formed composite material has been confirmed by scanning electron microscope (SEM) analysis. SEM images illustrated that the PANI were uniformly deposited on GN nanosheets. PANI/GN/Tb3+ composite material exhibited high electrical conductivity than the pristine PANI. Whats more, results also demonstrated that the synthesized composite material has found wide promising applications in capacitors. Finally, the conductive mechanism of PANI/GN/rare earth composite is discussed in this paper, the conductivity of nanocomposites offered upgrade first than descending latter tendency with different content of Tb3+ ions. The results should be attributed to the special electronic structure and excellent magnetic of rare earth ions, which can influence the polymer chains.

Synthesis and Characterization of NanoGs-PPy/Epoxy Nanocomposites by In Situ Polymerization

NanoGs-PPy/epoxy nanocomposites were successfully prepared by in situ polymerization of pyrrole in the presence of NanoGs. The morphology and stability of the materials were characterized by scanning electron microscope and thermogravimetric analysis. Electrical conductivity and mechanical properties of the composites were also investigated. The results showed that the NanoGs-PPy/epoxy composites not only maintained its good electrical conductivity but also keep favorable mechanical properties.

The construction and application of chiral electrochemical sensors

The review is based on the construction and application of chiral electrochemical sensors in the last three years and presents recent advances in applications of chiral electrochemical sensors based on a three-point interaction and the methods for fabricating chiral surfaces for enantioselective recognition.

Superparamagnetic functional C@Fe3O4 nanoflowers: development and application in acetaminophen delivery

Fe3O4 nanoflowers (NFs) were synthesized via an aqueous solution method and coated with carbon through an in situ carbonization process. The synthesized C@Fe3O4 composites were further modified with strong oxidizing agents, forming functional C@Fe3O4 (FCF) flower-like composites with porous superstructure. Finally, the stable composites were used in the drug delivery test under ambient conditions; the amount of acetaminophen adsorption on the composite can weigh up to 25.07% in 3 h. The FCF composites show excellent porosity (165.23 m2 g-1) and magnetic properties (24.33 emu g-1). The -COOH, C[double bond, length as m-dash]O and -OH groups in the composites could be used for interaction with biomolecules that contain -OH, C[double bond, length as m-dash]O and -NH2 groups. Therefore, the composite exhibits a sustained release model, with release rates of 51% in the first 6 h and 73% in 12 h. This special character gives the composites potential to be used in magnetic bio-separation and drug/gene delivery. The findings in this study are useful for the engineering design of porous iron oxide coated with functional carbon that is used for medical delivery applications and other biomedical devices.

The construction of electrochemical chiral interfaces using hydroxypropyl chitosan

A simple chiral electrochemical sensor based on hydroxypropyl chitosan (HPCS) covalently bound to multi-walled carbon nanotubes (MWCNTs) was developed for the recognition of mandelic acid (MA) enantiomers. HPCS preferably combines with (S)-MA over (R)-MA, which was attributed to the favorable host–guest interactions between HPCS and the MA enantiomers. In addition, the recognition efficiency was significantly increased after hydroxypropyl groups were grafted onto chitosan (CS), which may be due to a stereo-hindrance effect. Moreover, the electrochemical recognition of amino acid enantiomers was investigated; the functional groups of the enantiomers play an important role in the enantioselective discrimination.

Synthesis of PPy/Nano-Graphite Sheets/TbCl3 Composites with High Conductivity

Nano-graphite sheets (NanoGs) were prepared by treating the expanded graphite with sonication in 95% alcohol solution. The polypyrrole (PPy)/NanoGs/TbCl3 nanocomposites were successfully prepared by in-situ polymerization. The structure, morphology, and stability of the composites are characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), and thermogravimetric analysis (TG). The PPy/NanoGs/TbCl3 nanocomposites exhibited much higher electrical conductivity and better thermal property than the pristine PPy. The electrical conductivity of these nanocomposites were adjusted by changing different wt% of the NanoGs and TbCl3, the conductivity of the composites was reached 80.0 S/cm with the 7 wt% of TbCl3 and 3 wt% of NanoGs.

Facile synthesis of highly conductive PPy/graphene nanosheet /Gd3+ composites

Highly conductive PPy/graphene nanosheet and PPy/graphene nanosheet/Gd3+ composites were prepared via in-situ polymerization with p-toluenesulfonic acid as a dopant and FeCl3 as an oxidant. The effects of graphene nanosheet obtained by two different synthetic methods and Gd3+ on the electrical conductivity of the composites were investigated. The results showed that the graphene nanosheet as a filler had an effect on the conductivity of PPy/graphene nanosheet similar to PPy/graphene nanosheet/Gd3+ composites, which played an important role in forming a conducting network in PPy matrix. Thermal gravimetric analysis demonstrated an improved thermal stability of PPy in the PPy/graphene nanosheet/Gd3+ composites. The microstructures of PPy/graphene nanosheet/Gd3+ were characterized by scanning electron microscope and transmission electron microscope examinations.

Preparation and characterisation of PPy/NanoGs/Fe3O4 conductive and magnetic nanocomposites

Nanocomposites composed of polypyrrole (PPy), graphite nanosheets (NanoGs), magnetite (Fe3O4) nanoparticles, have been successfully synthesised with a two-step process. First, we prepared NanoGs/Fe3O4 powder via wet chemical co-precipitation method. Next, pyrrole was polymerised in the suspension of NanoGs/Fe3O4 and then PPy/NanoGs/Fe3O4 nanocomposites were produced. The products were characterised by Fourier-transform infrared spectroscopy, Transmission electron microscopy, Thermogravimetric, conductivity and magnetisation analysis. The result showed that the conductivity of the PPy/NanoGs/Fe3O4 composites, compared with pure PPy, increased dramatically. And the saturation magnetisation of nanocomposites increased with the increase of the volume fraction of the Fe3O4 particles. In addition, according to the thermal gravimetric analysis, compared with PPy, nanocomposites exhibited enhanced thermal stability due to the introduction of NanoGs/Fe3O4. The PPy/NanoGs/Fe3O4 composites show potential applications in electric–magnetic shield materials.

Synthesis of hierarchically structured iron oxide in magnetic field and their hydrophobic property

A special 3D morphology of Fe3O4 flowers was obtained through a magnetic field induced method. The products showed a large contact angle and were used as hydrophobing agents on the iron plate due to their special morphology and good hydrophobic properties. After calcination, the flower-like nanostructures of Fe3O4 can be transformed into γ-Fe2O3. The samples were characterized by SEM, TEM, XRD, VSM and CAs, and the results show that these special nanoflowers can be potentially suitable to synthesize hydrophobic material to protect against dampness, moisture and rusting of iron. Furthermore, a possible formation mechanism of the flower-like nanoparticles is discussed in detail. In prospect, this method is simple and facile and could synthesize other metal oxides under such experimental conditions.