BaFe12O19 fibers was prepared via an aqueous sol-gel process using Fe（OH）（HCOO）2 synthesized in laboratory and Ba（CH3COO）2 as the original materials and citrate as the chelate. The rheological behaviour of spinn...BaFe12O19 fibers was prepared via an aqueous sol-gel process using Fe（OH）（HCOO）2 synthesized in laboratory and Ba（CH3COO）2 as the original materials and citrate as the chelate. The rheological behaviour of spinnable sol was characterized on rheometer, and the development of gel fibers to barium ferrite fibers was studied by IR, TG and XRD. Morphology observation of the fibers was given on SEM, and the diameter of the obtained fibers was between 5 and 10 um corresponding to different additives. The additives affected the surface tension of the precursor sol which had close relation to the microstructure of fibers. Sucrose and hydroxyethylic cellulose could improve the surface tension while diethanolamine and hexadecylamine reduce that of the decylamine as an additive, well-structured BaFe12O19 precursor sol. And using diethanolamine or hexafibers could be obtained.展开更多
A new type of thermal stabilizer, antimony pent（isooctyl thioglycollate）(Sb(SCH2COOC8H17)5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was ox...A new type of thermal stabilizer, antimony pent（isooctyl thioglycollate）(Sb(SCH2COOC8H17)5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was oxidized into colloidal antimony peroxide. Then antimony peroxide and isooctyl thioglycollate reacted stoichiometrically for 2 h with the yield of 87%. This compound was used as thermal stabilizer for polyvinyl chloride（PVC）. The results show that the thermal stability time is 52min at 200℃ by heat-ageing oven test when adding 2.5% thermal stabilizer to PVC resin. Compared with antimony tris（isooctyl thiolycollate）, the initial thermal stability of antimony pent（isooctyl thioglycollate） is better than that of antimony tris（isooctyl thioglycollate）, while the long-term thermal stability time is shorter than that of antimony tris（isooctyl thioglycollate）. Meanwhile, the synergism of antimony pent（isooctyl thioglycollate） with calcium stearate was studied, indicating that when the mass ratio of antimony pent（isooctyl thioglycollate） to calcium stearate is （2∶1,） the thermal stability time of PVC is 58min.展开更多
Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the se...Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis （SGCS） method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% （by volume） C02. The mass ratio of CaO to CaZr03 as 8：2 （designated as CasZr2） was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area （SA） ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.展开更多
It is difficult to directly dope europium complexes in gel because the excessive water or high acidic condition may lead to their decomposition. We prepared a novel homogeneous TiO2 gel containing Eu-phen complexes by...It is difficult to directly dope europium complexes in gel because the excessive water or high acidic condition may lead to their decomposition. We prepared a novel homogeneous TiO2 gel containing Eu-phen complexes by using an in-situ synthesis method. The formation of Eu-phen complexes in sol-gel derived TiO2 was confirmed by luminescence excitation spectra. The effects of temperature and aging time on in-situ synthesis are discussed. The luminescence spectra of gel containing europium complexes were also compared with the pure Eu-phen complexes.展开更多
A novel copper-mediated solvothermal method was proposed for synthesizing colloidal spheres of a new composition, palladium iodide （PdI2）. Typical procedure was designed to involve the introduction of cupric chlori...A novel copper-mediated solvothermal method was proposed for synthesizing colloidal spheres of a new composition, palladium iodide （PdI2）. Typical procedure was designed to involve the introduction of cupric chloride （CuCI2） as weak oxidant. CuCI2 was found to be essential for preventing the easy formation of palladium deposits as well as facilitating the synthesis and assembly. Under the co-effect of CuC12 and the surfactant of polyvinylpyrrolidone （PVP）, neutral PdI2 colloidal spheres with narrow size distribution were successfully produced. Such ion-assisted synthetic method is believed to be prospective in producing well-constructed nanostructures.展开更多
基金Supported by National Natural Science Foundation of China(No.50506020)Natural Science Foundation of Tianjin(No.043605211)Young Teacher Foundation of Tianjin University(No.5110103)
文摘BaFe12O19 fibers was prepared via an aqueous sol-gel process using Fe（OH）（HCOO）2 synthesized in laboratory and Ba（CH3COO）2 as the original materials and citrate as the chelate. The rheological behaviour of spinnable sol was characterized on rheometer, and the development of gel fibers to barium ferrite fibers was studied by IR, TG and XRD. Morphology observation of the fibers was given on SEM, and the diameter of the obtained fibers was between 5 and 10 um corresponding to different additives. The additives affected the surface tension of the precursor sol which had close relation to the microstructure of fibers. Sucrose and hydroxyethylic cellulose could improve the surface tension while diethanolamine and hexadecylamine reduce that of the decylamine as an additive, well-structured BaFe12O19 precursor sol. And using diethanolamine or hexafibers could be obtained.
基金Project supported by the Postdoctoral Foundation of Central South University
文摘A new type of thermal stabilizer, antimony pent（isooctyl thioglycollate）(Sb(SCH2COOC8H17)5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was oxidized into colloidal antimony peroxide. Then antimony peroxide and isooctyl thioglycollate reacted stoichiometrically for 2 h with the yield of 87%. This compound was used as thermal stabilizer for polyvinyl chloride（PVC）. The results show that the thermal stability time is 52min at 200℃ by heat-ageing oven test when adding 2.5% thermal stabilizer to PVC resin. Compared with antimony tris（isooctyl thiolycollate）, the initial thermal stability of antimony pent（isooctyl thioglycollate） is better than that of antimony tris（isooctyl thioglycollate）, while the long-term thermal stability time is shorter than that of antimony tris（isooctyl thioglycollate）. Meanwhile, the synergism of antimony pent（isooctyl thioglycollate） with calcium stearate was studied, indicating that when the mass ratio of antimony pent（isooctyl thioglycollate） to calcium stearate is （2∶1,） the thermal stability time of PVC is 58min.
基金Supported by the National Natural Science Foundation of China(51276210,50906030,31301586)the Partial Financial Grant of North China University of Water Resources and Electric Power(201012)the National Basic Research Program of China(2011CB707301)
文摘Calcium looping method has been considered as one of the efficient options to capture C02 in the combustion Ilue gas. CaO-based sorbent is the basis for application of calcium looping and should be subjected to the severe calcination condition so as to obtain the concentrated C02 stream. In this research, CaO/CaZrO3 sorbents were synthesized using the sol-gel combustion synthesis （SGCS） method with urea as fuel. The cyclic reaction performance of the synthesized sorbents was evaluated on a lab-scaled reactor system through calcination at 950 ℃ in a pure C02 atmosphere and carbonation at 650 ℃ in the 15% （by volume） C02. The mass ratio of CaO to CaZr03 as 8：2 （designated as CasZr2） was screened as the best option among all the synthesized CaO sorbents for its high CO2 capture capacity and carbonation conversion at the initial cycle. And then a gradual decay in the C02 capture capacity was observed at the following 10 successive cycles, but hereafter stabilized throughout the later cycles. Furthermore, structural evolution of the carbonated CasZr2 over the looping cycles was investigated. With increasing looping cycles, the pore peak and mean grain size of the carbonated CasZr2 sorbent shifted to the bigger direction but both the surface area （SA） ratio and surface fractal dimension Ds decreased. Finally, morphological transformation of the carbonated CasZr2 was observed. Agglomeration and edge rounding of the newly formed CaC03 grains were found as aggravated at the cyclic carbonation stage. As a result, carbonation of CasZr2 with C02 was observed only confined to the external active CaO by the fast formation of the CaC03 shell outside, which occluded the further carbonation of the unreacted CaO inside. Therefore, enough attention should be paid to the carbonation stage and more effective activation measures should be explored to ensure the unreacted active CaO fully carbonatPd river the extended Ioonin cycles.
基金Project (No. 2004C210023) supported by Science Planning Project of Zhejiang Province, China
文摘It is difficult to directly dope europium complexes in gel because the excessive water or high acidic condition may lead to their decomposition. We prepared a novel homogeneous TiO2 gel containing Eu-phen complexes by using an in-situ synthesis method. The formation of Eu-phen complexes in sol-gel derived TiO2 was confirmed by luminescence excitation spectra. The effects of temperature and aging time on in-situ synthesis are discussed. The luminescence spectra of gel containing europium complexes were also compared with the pure Eu-phen complexes.
基金supported by the National Basic Program of China for Nanoscience and Nanotechnology (973 Program,2011CB932401)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (20921001)
文摘A novel copper-mediated solvothermal method was proposed for synthesizing colloidal spheres of a new composition, palladium iodide （PdI2）. Typical procedure was designed to involve the introduction of cupric chloride （CuCI2） as weak oxidant. CuCI2 was found to be essential for preventing the easy formation of palladium deposits as well as facilitating the synthesis and assembly. Under the co-effect of CuC12 and the surfactant of polyvinylpyrrolidone （PVP）, neutral PdI2 colloidal spheres with narrow size distribution were successfully produced. Such ion-assisted synthetic method is believed to be prospective in producing well-constructed nanostructures.
