An apparatus was set up for in situ UV- Vis determintion of ethylene polymerization under atmospheric pressure. In three different solvents, tetrahydrofuran(THF), chlorobenzene and dimethyl formamide (DMF), and using ...An apparatus was set up for in situ UV- Vis determintion of ethylene polymerization under atmospheric pressure. In three different solvents, tetrahydrofuran(THF), chlorobenzene and dimethyl formamide (DMF), and using MAO as cocatalyst,α- diimine/nickel catalytic system was prepared for ethylene polymerization with the UV- Vis testing system. In THF, active peak at 545 nm and inactive peak at 660 nm were observed. In chlorobenzene, active peak at 520 nm, 570 nm, and inactive peak at 660 nm were also observed. The regularities of growth and disappearence of active peaks were investigated. The structure of active species and solvent effect were discussed.展开更多
Nanometer multilayer composite films of lead phthalocyanine(PbPc) and vanadyl phthalocyanine(VOPc) were prepared by vacuum vapor deposition. It is found that a new absorption peak around 940 nm appeared as discovered ...Nanometer multilayer composite films of lead phthalocyanine(PbPc) and vanadyl phthalocyanine(VOPc) were prepared by vacuum vapor deposition. It is found that a new absorption peak around 940 nm appeared as discovered by UV-visible absorption analysis. Compared to the Q bands absorption of single component films of VOPc and PbPc, the new peak is red-shifted. It is also found that the new peak shows a small red-shift when the thickness of the PbPc layer increases. It is concluded that the new peak is a result of composition, and the red-shift is caused by both interface effect and quantum confinement effect of the nanometer multilayered structure.展开更多
文摘An apparatus was set up for in situ UV- Vis determintion of ethylene polymerization under atmospheric pressure. In three different solvents, tetrahydrofuran(THF), chlorobenzene and dimethyl formamide (DMF), and using MAO as cocatalyst,α- diimine/nickel catalytic system was prepared for ethylene polymerization with the UV- Vis testing system. In THF, active peak at 545 nm and inactive peak at 660 nm were observed. In chlorobenzene, active peak at 520 nm, 570 nm, and inactive peak at 660 nm were also observed. The regularities of growth and disappearence of active peaks were investigated. The structure of active species and solvent effect were discussed.
基金supported by the National Natural Science Foundation of China(10676007)Program for New Century Excellent Talents at the University of Fujian Province,China(HX2006-103)~~
文摘Nanometer multilayer composite films of lead phthalocyanine(PbPc) and vanadyl phthalocyanine(VOPc) were prepared by vacuum vapor deposition. It is found that a new absorption peak around 940 nm appeared as discovered by UV-visible absorption analysis. Compared to the Q bands absorption of single component films of VOPc and PbPc, the new peak is red-shifted. It is also found that the new peak shows a small red-shift when the thickness of the PbPc layer increases. It is concluded that the new peak is a result of composition, and the red-shift is caused by both interface effect and quantum confinement effect of the nanometer multilayered structure.
