The uniform zirconia nanoparticle multilayers/micrometer-sized silica particle(ZrO 2/SiO 2) was prepared for HPLC support material by layer-by-layer(LbL) self-assembly technique. XRD pattern shows that the crystalline...The uniform zirconia nanoparticle multilayers/micrometer-sized silica particle(ZrO 2/SiO 2) was prepared for HPLC support material by layer-by-layer(LbL) self-assembly technique. XRD pattern shows that the crystalline of nanometer particles on the surface is pure tetragonal zirconia, with a diameter of 13^9 nm. The specific surface area, pore volume and pore size of the material are 172.53 m 2/g, 0.378 4 cm 3/g, and 8.5 nm, respectively. The novel support not only has the mechanical strength and chemical stability of zirconia, but also has the good chromatographic features such as larger surface area, better permeability, less background pressure.展开更多
In this report the synthesis and characterization of chiral stationary phase of cellulose tris(3,5 dimethylphenylcarbamate) coated zirconia(CDMPC ZrO 2 CSP) was described. Direct optical resolutions of acidic racemate...In this report the synthesis and characterization of chiral stationary phase of cellulose tris(3,5 dimethylphenylcarbamate) coated zirconia(CDMPC ZrO 2 CSP) was described. Direct optical resolutions of acidic racemate naproxen and its derivatives on the phase were investigated. Surface property of zirconia affects the chiral separation of naproxen greatly. Naproxen could not be eluted from the column unless an acidic modifier was present in the mobile phase. However, good chiral resolutions were obtained for its ester derivatives. The influences of loading amount of stationary phase, molecular structure of compounds, type of alcohols as the modifier and their concentration in mobile phase on chiral resolution were studied. The chiral recognition mechanism of the chiral stationary phase was discussed.展开更多
The surface properties of zirconia-based supports,ZrO-2/SiO-2 and ZrO-2,were compared.ZrO-2/SiO-2 prepared by layer-by-layer self-assembly(LbL SA) technique showed more favorable characteristics for HPLC applications ...The surface properties of zirconia-based supports,ZrO-2/SiO-2 and ZrO-2,were compared.ZrO-2/SiO-2 prepared by layer-by-layer self-assembly(LbL SA) technique showed more favorable characteristics for HPLC applications compared with ZrO-2 prepared by modified oil-emulsion method.The specific surface area and pore volume of ZrO-2/SiO-2 were about 18 and 20 times of those of ZrO-2 respectively.The pore of ZrO-2/SiO-2 support was ideal cylindrical shape,but ZrO-2 support had some \!ink bottle\" shaped-pores which was unfavorable for HPLC separations.Pore size distribution of ZrO-2/SiO-2 supports was more uniform than that of ZrO-2 supports.展开更多
文摘The uniform zirconia nanoparticle multilayers/micrometer-sized silica particle(ZrO 2/SiO 2) was prepared for HPLC support material by layer-by-layer(LbL) self-assembly technique. XRD pattern shows that the crystalline of nanometer particles on the surface is pure tetragonal zirconia, with a diameter of 13^9 nm. The specific surface area, pore volume and pore size of the material are 172.53 m 2/g, 0.378 4 cm 3/g, and 8.5 nm, respectively. The novel support not only has the mechanical strength and chemical stability of zirconia, but also has the good chromatographic features such as larger surface area, better permeability, less background pressure.
文摘In this report the synthesis and characterization of chiral stationary phase of cellulose tris(3,5 dimethylphenylcarbamate) coated zirconia(CDMPC ZrO 2 CSP) was described. Direct optical resolutions of acidic racemate naproxen and its derivatives on the phase were investigated. Surface property of zirconia affects the chiral separation of naproxen greatly. Naproxen could not be eluted from the column unless an acidic modifier was present in the mobile phase. However, good chiral resolutions were obtained for its ester derivatives. The influences of loading amount of stationary phase, molecular structure of compounds, type of alcohols as the modifier and their concentration in mobile phase on chiral resolution were studied. The chiral recognition mechanism of the chiral stationary phase was discussed.
文摘The surface properties of zirconia-based supports,ZrO-2/SiO-2 and ZrO-2,were compared.ZrO-2/SiO-2 prepared by layer-by-layer self-assembly(LbL SA) technique showed more favorable characteristics for HPLC applications compared with ZrO-2 prepared by modified oil-emulsion method.The specific surface area and pore volume of ZrO-2/SiO-2 were about 18 and 20 times of those of ZrO-2 respectively.The pore of ZrO-2/SiO-2 support was ideal cylindrical shape,but ZrO-2 support had some \!ink bottle\" shaped-pores which was unfavorable for HPLC separations.Pore size distribution of ZrO-2/SiO-2 supports was more uniform than that of ZrO-2 supports.
