Yuan Chunwei

Catalytic growth of carbon nanotubes from the internal surface of Fe-loading mesoporous molecular sieves materials

Catalytic formation of carbon nanotubes on Fe-loading hexagonal mesoporous molecular sieve Fe/SiHMS and microporous molecular sieve Fe/NaY has been investigated. TEM pictures, together with the different porous properties of SiHMS and NaY, show us that the carbon nanotubes probably grow inside the channels of Fe/SiHMS and on the external surface of Fe/NaY. The Fe(2p) binding energy (BE) suggests a stronger interaction between SiHMS and the deposited iron oxide species than that between NaY and iron species. The BE of Si, O and Fe elements for Fe/SiHMS vary much before and after the catalytic synthesis of carbon nanotubes, whereas the BE for NaY changes little. The above XPS information can serve as a supplement to TEM analysis.

Photocatalytic degradation of trace-level of Microcystin-LR by nano-film of titanium dioxide

Microcystins, a group of hepatotoxin produced by cyanobacteria in eutrophic freshwater, have proven unreliable to be removed by conventional treatments. In this study, the photocatalytic degradation experiments of Microcystin-LR were conducted using nano-TiO2 thin film, prepared by solgel and dip-coating method, with low UVA intensity irradiation. Analysis results from SPE (solid-phase extraction) combined with HPLC method showed that Microcystin-LR whose initial concentration (μg/L) around that occurs naturally was easily to be removed by photocatalytic system. The degradation efficiency of toxin was influenced by the pH conditions, initial concentration and UV intensity. The maximum initial rate of photocatalytic degradation occurred at pH 4 and over 95% of 20 μg/L Microcystin-LR was decomposed within 120 min under 400 μW/cm2 UV illumination. The kinetic equations and parameters revealed that degradation reaction of trace level MC-LR, which was depicted by Langmuir-Hinshelwood kinetics model, was in accordance with pseudo first order kinetics process in appearance well. Under the condition of pH=6.7, irradiation intensity=400 μW/cm2 and initial concentration=20 μg/L, the corresponding pseudo-first-order rate constant k and half-life were determined to be 0.0157 min−1 and 44 min, respectively. During the range of 200–1000 μW/cm2, the degradation rate increases with incident intensity to the 0.82 power and the corresponding apparent quantum yield (Φapp) was found to be 5.19×10−8 g/J approximately.

Interaction of malachite green with lecithin liposomes

Abstract The interaction of malachite green (MG) with lecithin liposomes simulating life system is studied by UV, IR and fluorescent spectroscopy. The results show that MG can be located in the palisade of lecithin liposomes spontaneously, which leads to the increase of the micropolarity (I1/I3) and the decrease of the fluorescence polarization (P) of lecithin liposomes. The binding constant K of MG with lecithin liposomes and the distribution coefficient KD of MG between the lecithin liposomes and the aqueous phase decreases with the increase of the MG concentration.

Preparation of molecularly imprinted microspheres by photo-grafting on supports modified with iniferter

Molecularly imprinted microspheres (MIMs) of D-mandelic acid were synthesized in this study. Chloromethylated polystyrene beads modified with iniferter were used as supports for photo-grafting of a molecularly imprinted polymer (MIP) layer. The polymers were characterized by FT-IR, elemental analysis and thermo-gravimetric analysis to testify the polymer formation and its thermal stability. Scanning electron micrographs (SEM) show that the MIP particles are mono-dispersed and well-spherical, with the average diameter of 4.38 μm and size distribution coefficient of 1.02. Furthermore, the MIMs were packed in a stainless steel column and evaluated as stationary phases in high performance liquid chromatography (HPLC). The prepared MIP exhibited a considerable capability of chiral separation between template and its enantiomer. Accordingly, this kind of MIP is likely to have wide applications in chemical sensing, chromatographic analysis and solid phase extraction.

Morphological manipulation of PC liposome by controlled bolaamphiphile doping

The morphological characterization of aqueous dispersions of PC amphiphile and bolaamphiphile AEC was observed by transmission electron microscopy, the measurement of the liposomal membrane fluidity, differential scanning calorimetry, 5(6)-CF release from liposome and zeta potential measurement. Results indicate that the bolaamphiphile AEC can be included within conventional egg-PC liposome bilayer, which leads to the decrease of liposomal membrane fluidity (P) and the release behavior of 5(6)-CF. This behavior could be due to the property of bolaamphiphile AEC and the good miscibility of bolaamphiphile AEC with PC.

Using biomedical sensor - reflectometry interference spectroscopy for evaluation of biocompatibility of biomaterials

Using a biomedical sensor setup RIfS we have investigated the kinetic behavior of bovine serum albumin (BSA), human fibrinogen (FIb) and human IgG adsorbed onto surfaces of hydroxyapatite (HA) and polyurethane (PU) H50-50. According to the operation principle of RIfS and the molecular dimensions of three kinds of proteins, a formula to calculate the adsorbed layers of proteins onto the surface of HA and PU H50-50 has been introduced. The results show that the adsorbed layers of three kinds of proteins on the surface of HA are 1.0751 for IgG 0.9684 for BSA, 0.7464 for FIb and that of PU H50-50 are: 0.8199 for IgG 0.7964 for BSA, 0.6120 for FIb. It is shown that RIfS can perform a kinetic, real time and in situ analysis of plasma proteins adsorbed on a surface of biomaterials. From this study the potential application of RIfS as a new analytical tool in the evaluation of the biocompatibility of biomaterials was confirmed and the experiences of preparing suitable nanograde film from inorganic and organic biomaterials for a RIfS experiment were accumulated.

Liposome Formation in Mixed Aqueous Solution of Tripple‐Tailed Cationic Surfactant and Phosphatidylcholine

Abstract This paper describes the morphological characterization of aqueous dispersions of phosphatidylcholine (PC) and of a tripple‐tailed cationic phosphine oxide surfactant, PTA, by transmission electron microscopy (TEM) fluorescence polarization, and UV absorbance measurements. Results indicate that the addition of PTA between PC molecules helps in liposome organization. This behavior could be due to the cup‐like structure of the combination of PTA and PC, which is expected to generate geometrically curved aggregates.

Simulation of Human Vision by Image Evolution in Light-excitable Nonlinear Optical Medium¶

Abstract The nonlinear optical membrane used for image processing was prepared using tetraethyl silicate by sol–gel method under mild conditions. Ru(bpy)3Cl2 (bpy, bipyridine) was immobilized in the sol–gel matrix. This light-excitable membrane containing Ru(bpy)3Cl2 as photocatalyst could catalyze the Belousov–Zhabotinsky reaction by illumination. Our results indicated that a fine-definition image processing could be autoperformed when projecting a picture on this medium. The imaging process was an image evolution process, which was similar to that of the human vision process.

The experimental research of millimeter wave radiation effects on the amount of SOD in human blood

Experiments about the effects of millimeter waves on superoxide dismutase (SOD) activity in human blood are presented. Two conclusions are drawn, namely: 1) millimeter wave radiation could result in the decrease of SOD activity in human blood; 2) radiation conditions, i.e. frequency, intensity, acting time of radiation, would change the amount of SOD in human blood. These effects must be taken account in the biomedical application of millimeter wave radiation.

Enhancement of Organic Electroluminescent Intensity by Doping Hole-Property Polymers

Organic electroluminescent (EL) diodes with one-layer poly(3-octylthiophene) (P3OT) and P3OT doped with poly(N-vinylcarbazole) (PVK) (P3OT/PVK) as EL emitting layer sandwiched between indium/tin oxide (ITO) and aluminium electrodes have been fabricated by spin coating onto ITO respectively. The P3OT/PVK EL diode starts to emit red-orange light at 5 V in our experiment, the luminance and the current for the P3OT/PVK EL diode at bias voltage was compared with those for the only P3OT EL diode, indicating that the PVK dopant has power over the P3OT electroluminescence.