The transition metal ion doped TiO 2 nanoparticles were prepared with hydrothermal method, and the effects of doping different metal ions on the ability of TiO 2 in photocatalyzing degradation of rhodamine B(RB) were ...The transition metal ion doped TiO 2 nanoparticles were prepared with hydrothermal method, and the effects of doping different metal ions on the ability of TiO 2 in photocatalyzing degradation of rhodamine B(RB) were studied. The results showed that the doping of Fe 3+ , Co 2+ , Ni 2+ and Cr 3+ in TiO 2 nanoparticles made the photocatalytic efficiency of the TiO 2 particles reduce and the higher the initial content of Fe 3+ , the lower the ability of TiO 2 in photocatalyzing the degradation of RB. But the doping of Zn 2+ and Cd 2+ , especially Zn 2+ , made the photocatalytic efficiency of the TiO 2 particles enhance, showing a great increase of the rate constant( k ) and the initial reaction rate( r ini ).展开更多
The crystallization of barium oxalate in the presence of a double-hydrophilic block copolymer poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) was investigated. Barium oxalate crystals with a complex fo...The crystallization of barium oxalate in the presence of a double-hydrophilic block copolymer poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) was investigated. Barium oxalate crystals with a complex form, such as fan-like aggregates consisting of rod-like BaC 2O 4·H 2O crystals and spherical aggregates consisting of flake-like BaC 2O 4·3.5H 2O crystals were readily produced in aqueous solutions of PEG-b-PMMA. This result may provide an effective method for controlling the morphology and polymorph of inorganic crystals.展开更多
The crystallization of calcite from mixed alcohol water solvents in the presence of a double hydrophilic block copolymer poly(ethylene glycol) block poly(methacrylic acid)(PEG b PMAA) has been investigated. It was rev...The crystallization of calcite from mixed alcohol water solvents in the presence of a double hydrophilic block copolymer poly(ethylene glycol) block poly(methacrylic acid)(PEG b PMAA) has been investigated. It was revealed that with increasing the volume fractions of ethanol or isopropanol, the morphology of the CaCO 3 particles generally varies from peanuts through rods to spheres in the presence of the polymer. Specifically, uniform rounded calcite rods, which are about 2 μm in length with an aspect ratio of 2.6, were obtained in the isopropanol solution with volume fraction 50%.展开更多
The secondary structure parameters of partially hydrolyzed poly(acrylamide)(HPAM) in the process of chemical oil recovery have been determined by means of GPC-light scattering cooperation. It was found that the mean m...The secondary structure parameters of partially hydrolyzed poly(acrylamide)(HPAM) in the process of chemical oil recovery have been determined by means of GPC-light scattering cooperation. It was found that the mean molecular mass of HPAM had decreased to 4 to 8 times, the molecular mass distribution of HPAM became broad. It has been deduced that the molecular mass decrease of HPAM results from the HPAM degradation and the mechanical degradation is a determinant because the molecular mass distributions of HPAM after degradation were narrower than the results estimated with the random degradation theory. The chain flexibility somewhat decreased when HPAM solution flowed in underground sandstones in the period of 6 to 8 months, that is, (<S 2> n/<M> n) 1/2 increased from original 0.065 to 0.075 for HPAM in flooding 2 and 4 years and 0.081 for 6 years, which maybe imply HPMA further hydrolyzed under the underground weak basic condition of the oilfield.展开更多
文摘The transition metal ion doped TiO 2 nanoparticles were prepared with hydrothermal method, and the effects of doping different metal ions on the ability of TiO 2 in photocatalyzing degradation of rhodamine B(RB) were studied. The results showed that the doping of Fe 3+ , Co 2+ , Ni 2+ and Cr 3+ in TiO 2 nanoparticles made the photocatalytic efficiency of the TiO 2 particles reduce and the higher the initial content of Fe 3+ , the lower the ability of TiO 2 in photocatalyzing the degradation of RB. But the doping of Zn 2+ and Cd 2+ , especially Zn 2+ , made the photocatalytic efficiency of the TiO 2 particles enhance, showing a great increase of the rate constant( k ) and the initial reaction rate( r ini ).
文摘The crystallization of barium oxalate in the presence of a double-hydrophilic block copolymer poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) was investigated. Barium oxalate crystals with a complex form, such as fan-like aggregates consisting of rod-like BaC 2O 4·H 2O crystals and spherical aggregates consisting of flake-like BaC 2O 4·3.5H 2O crystals were readily produced in aqueous solutions of PEG-b-PMMA. This result may provide an effective method for controlling the morphology and polymorph of inorganic crystals.
文摘The crystallization of calcite from mixed alcohol water solvents in the presence of a double hydrophilic block copolymer poly(ethylene glycol) block poly(methacrylic acid)(PEG b PMAA) has been investigated. It was revealed that with increasing the volume fractions of ethanol or isopropanol, the morphology of the CaCO 3 particles generally varies from peanuts through rods to spheres in the presence of the polymer. Specifically, uniform rounded calcite rods, which are about 2 μm in length with an aspect ratio of 2.6, were obtained in the isopropanol solution with volume fraction 50%.
文摘The secondary structure parameters of partially hydrolyzed poly(acrylamide)(HPAM) in the process of chemical oil recovery have been determined by means of GPC-light scattering cooperation. It was found that the mean molecular mass of HPAM had decreased to 4 to 8 times, the molecular mass distribution of HPAM became broad. It has been deduced that the molecular mass decrease of HPAM results from the HPAM degradation and the mechanical degradation is a determinant because the molecular mass distributions of HPAM after degradation were narrower than the results estimated with the random degradation theory. The chain flexibility somewhat decreased when HPAM solution flowed in underground sandstones in the period of 6 to 8 months, that is, (<S 2> n/<M> n) 1/2 increased from original 0.065 to 0.075 for HPAM in flooding 2 and 4 years and 0.081 for 6 years, which maybe imply HPMA further hydrolyzed under the underground weak basic condition of the oilfield.
