纳米 Ti O2 改性不饱和聚酯树脂 ,其目的是对不饱和聚酯进行同时增韧增强改性。用“反应法”制备的纳米 Ti O2 /UPR,在纳米 Ti O2 与 UPR之间产生的新化学键将纳米 Ti O2 粒子接入 UPR长链上 ,这种新的结构决定了纳米 Ti O2 /UPR的性能...纳米 Ti O2 改性不饱和聚酯树脂 ,其目的是对不饱和聚酯进行同时增韧增强改性。用“反应法”制备的纳米 Ti O2 /UPR,在纳米 Ti O2 与 UPR之间产生的新化学键将纳米 Ti O2 粒子接入 UPR长链上 ,这种新的结构决定了纳米 Ti O2 /UPR的性能。研究结果表明 ,纳米 Ti O2 /UPR的反应活性高于 UPR,纳米 Ti O2 /UPR的冲击韧性和弯曲强度较 UPR分别提高 46%和 5 5 % ,纳米 Ti O2 /UPR的耐热性及介电性与展开更多
A new upconversion luminescence agent, 40CdF2·60BaF2·0.8ErO3, was synthesized and its fluorescent spectra were determined. This upconversion luminescence agent can emit five upconversion fluorescent peaks sh...A new upconversion luminescence agent, 40CdF2·60BaF2·0.8ErO3, was synthesized and its fluorescent spectra were determined. This upconversion luminescence agent can emit five upconversion fluorescent peaks shown in the fluorescent spectra whose wavelengths are all below 387 nm under the excitation of 488 nm visible light. This upconversion luminescence agent was mixed into nano rutile TiO2 powder by ultrasonic and boiling dispersion and the novel doped nano TiO2 photocatalyst utilizing visible light was firstly prepared. The doped TiO2 powder was charactered by XRD and TEM and its photocatalytic activity was tested through the photocatalytic degradation of methyl orange as a model compound under the visible light irradiation emitted by six three basic color lamps. In order to compare the photocatalytic activities, the same experiment was carried out for undoped TiO2 powder. The degradation ratio of methyl orange in the presence of doped nano TiO2 powder reached 32.5% under visible light irradiation at 20 h which was obviously higher than the corresponding 1.64% in the presence of undoped nano TiO2 powder, which indicate the upconversion luminescence agent prepared as dopant can effectively turn visible lights to ultraviolet lights that are absorbed by nano TiO2 particles to produce the electron-cavity pairs. All the results show that the nano rutile TiO2 powder doped with upconversion luminescence agent is a promising photocatalyst using sunlight for treating the industry dye wastewater in great force.展开更多
TiO2 nano powders with Mn concentration of 0 at%-12 at% were synthesized by the sol-gel process, and were annealed at 500 ℃ and 800 ℃ in air for 2 hrs. X-ray diffraction （XRD） measurements indicate that the Mn-TiO...TiO2 nano powders with Mn concentration of 0 at%-12 at% were synthesized by the sol-gel process, and were annealed at 500 ℃ and 800 ℃ in air for 2 hrs. X-ray diffraction （XRD） measurements indicate that the Mn-TiO2 nano powders with Mn concentration of 1 at% and 2 at% annealed at 500 and 800 ℃ are of pure anatase and rutile, respectively. The scanning electron microscope （SEM） observations reveal that the crystal grain size increases with the annealing temperature, and the high resolution transmission electron microscopy （HRTEM） investigations further indicate that the samples are well crystallized, confirming that Mn has doped into the TiO2 crystal lattice effectively. The room temperature ferromagnetism, which could be explained within the scope of the bound magnetic polaron （BMP） theory, is detected in the Mn-TiO2 samples with Mn concentration of 2 at%, and the magnetization of the powders annealed at 500 ℃ is stronger than that of the sample treated at 800 ℃. The UV-VIS diffuse reflectance spectra results demonstrate that the absorption of the TiO2 powders could be enlarged by the enhanced trapped electron absorption caused by Mn doping.展开更多
TiO_2 has attracted an increasing attention because of its variety of potential applications in environments and energies,such as gas sensing,self-cleaning,solar energy conversion, wettability and photo-catalysis appl...TiO_2 has attracted an increasing attention because of its variety of potential applications in environments and energies,such as gas sensing,self-cleaning,solar energy conversion, wettability and photo-catalysis applications.In this presentation,we summarize some progress in surface constructions of nano TiO_2 and its characterizations of physicochemistry and properties. (1)Superhydrophobic nanostructure TiO_2 films Superhydrophobic nanotube,nanopore and sponge-like structure TiO_2 films are fabricated ...展开更多
文摘纳米 Ti O2 改性不饱和聚酯树脂 ,其目的是对不饱和聚酯进行同时增韧增强改性。用“反应法”制备的纳米 Ti O2 /UPR,在纳米 Ti O2 与 UPR之间产生的新化学键将纳米 Ti O2 粒子接入 UPR长链上 ,这种新的结构决定了纳米 Ti O2 /UPR的性能。研究结果表明 ,纳米 Ti O2 /UPR的反应活性高于 UPR,纳米 Ti O2 /UPR的冲击韧性和弯曲强度较 UPR分别提高 46%和 5 5 % ,纳米 Ti O2 /UPR的耐热性及介电性与
基金The National Natural Science Foundation of China (No.20371023)
文摘A new upconversion luminescence agent, 40CdF2·60BaF2·0.8ErO3, was synthesized and its fluorescent spectra were determined. This upconversion luminescence agent can emit five upconversion fluorescent peaks shown in the fluorescent spectra whose wavelengths are all below 387 nm under the excitation of 488 nm visible light. This upconversion luminescence agent was mixed into nano rutile TiO2 powder by ultrasonic and boiling dispersion and the novel doped nano TiO2 photocatalyst utilizing visible light was firstly prepared. The doped TiO2 powder was charactered by XRD and TEM and its photocatalytic activity was tested through the photocatalytic degradation of methyl orange as a model compound under the visible light irradiation emitted by six three basic color lamps. In order to compare the photocatalytic activities, the same experiment was carried out for undoped TiO2 powder. The degradation ratio of methyl orange in the presence of doped nano TiO2 powder reached 32.5% under visible light irradiation at 20 h which was obviously higher than the corresponding 1.64% in the presence of undoped nano TiO2 powder, which indicate the upconversion luminescence agent prepared as dopant can effectively turn visible lights to ultraviolet lights that are absorbed by nano TiO2 particles to produce the electron-cavity pairs. All the results show that the nano rutile TiO2 powder doped with upconversion luminescence agent is a promising photocatalyst using sunlight for treating the industry dye wastewater in great force.
基金Project supported by the Innovation Foundation of BUAA for PhD Graduates (Grant No. 292122)Equipment Research Foundation of China
文摘TiO2 nano powders with Mn concentration of 0 at%-12 at% were synthesized by the sol-gel process, and were annealed at 500 ℃ and 800 ℃ in air for 2 hrs. X-ray diffraction （XRD） measurements indicate that the Mn-TiO2 nano powders with Mn concentration of 1 at% and 2 at% annealed at 500 and 800 ℃ are of pure anatase and rutile, respectively. The scanning electron microscope （SEM） observations reveal that the crystal grain size increases with the annealing temperature, and the high resolution transmission electron microscopy （HRTEM） investigations further indicate that the samples are well crystallized, confirming that Mn has doped into the TiO2 crystal lattice effectively. The room temperature ferromagnetism, which could be explained within the scope of the bound magnetic polaron （BMP） theory, is detected in the Mn-TiO2 samples with Mn concentration of 2 at%, and the magnetization of the powders annealed at 500 ℃ is stronger than that of the sample treated at 800 ℃. The UV-VIS diffuse reflectance spectra results demonstrate that the absorption of the TiO2 powders could be enlarged by the enhanced trapped electron absorption caused by Mn doping.
文摘TiO_2 has attracted an increasing attention because of its variety of potential applications in environments and energies,such as gas sensing,self-cleaning,solar energy conversion, wettability and photo-catalysis applications.In this presentation,we summarize some progress in surface constructions of nano TiO_2 and its characterizations of physicochemistry and properties. (1)Superhydrophobic nanostructure TiO_2 films Superhydrophobic nanotube,nanopore and sponge-like structure TiO_2 films are fabricated ...
