ß-Cyclodextrin modified anionic and cationic acrylamide polymers for enhancing oil recovery.

Both of acrylamide and allyl-ß-cyclodextrin are utilized to react with acrylic acid and dimethyl diallyl ammonium chloride respectively to synthesize the novel anionic acrylamide polymer and cationic acrylamide polymer by redox free-radical copolymerization. The structures of copolymers are characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. Subsequently, the copolymers are evaluated on several aspects such as optimum polymerization conditions, intrinsic viscosity, interfacial tension and stability experiments. It is found that the anionic and cationic acrylamide polymers containing cyclodextrin moieties show better performances on interfacial tension, salt resistance, temperature tolerance, viscosification property and shear resistance than that of polyacrylamide. By the comprehensive comparison and analysis, the anionic polymer is more conductive to decrease the interfacial tension for the tertiary oil recovery process, while the cationic polymer is more suitable for enhancing oil recovery in high-temperature and high-mineralization oilfield.

Characterization of microstructure of ibuprofen-hydroxypropyl-beta-cyclodextrin and ibuprofen-beta-cyclodextrin by atomic force microscope / 药学学报

The microstructures of ibuprofen-hydroxypropyl-bets-cyclodextrin (IBU-HP-beta-CyD) and ibuprofen-beta-cyclodextrin (IBU-beta-CyD) were observed by atomic force microscope (AFM). The high resolving capability of AFM has the tungsten filament probe with the spring constant of 0.06 N x m(-1). Samples were observed in a small scale scanning area of 10.5 nm x 10.5 nm and 800 x 800 pixels. The original scanning images were gained by tapping mode at room temperature. Their three-dimensional reconstruction of microstructure was performed by G3DR software. The outer diameters of HP-beta-CyD and beta-CyD are 1.53 nm. The benzene diameter of IBU is 0.62 nm, fitting to the inner diameters of HP-beta-CyD and beta-CyD. The benzene and hydrophobic chain of IBU enter into the hole of cyclodextrin at 1:1 ratio. The results were evidenced by IR, X-ray diffraction and the phase solubility.

Identification and Screening of Broad-spectrum Antibiotics-producing Strains / 微生物学通报

60 strains which have antimicrobial activity had been isolated from nutritious soil in China in the study.We have further selected 1 strain which product broad-spectrum antibiotics using agar well-diffusion method.The strain was identified Brevibacillus laterosporus after physiological biochemical characteristic experiments,sequencing of 16S rDNA and cluster analysis,named S62-9.