Indium tin oxide (ITO) nanoparticles were synthesized by precipitation method from granulated indium and oxalate tin. The ITO particles were characterized by means of XRD, BET and TEM. The tin doping decreases the cry...Indium tin oxide (ITO) nanoparticles were synthesized by precipitation method from granulated indium and oxalate tin. The ITO particles were characterized by means of XRD, BET and TEM. The tin doping decreases the crystallite size, increases the specific surface area and decreases the lattice volume of the ITO nanoparticles. The absence of chlorine ions in the synthesis greatly increases the particles′ purity, decreases the agglomeration and improves the synthesis efficiency. This synthesis process to ITO nanoparticles is now in pilot-scale production in: Light & Future Advanced Material Co. LTD, Daegu, Korea.展开更多
Ti4+-mixed FePO4·xH2O precursor was prepared by co-precipitation method,with which Ti4+ cations were added in the process of preparing FePO4·xH2O to pursue an effective and homogenous doping way.Ti4+-doped L...Ti4+-mixed FePO4·xH2O precursor was prepared by co-precipitation method,with which Ti4+ cations were added in the process of preparing FePO4·xH2O to pursue an effective and homogenous doping way.Ti4+-doped LiFePO4 was prepared by an ambient-reduction and post-sintering method using the as-prepared precursor,Li2CO3 and oxalic acid as raw materials.The samples were characterized by scanning electron microscopy (SEM),X-ray diffractometry (XRD),electrochemical impedance spectroscopy (EIS),and electrochemical charge/discharge test.Effects of Ti4+-doping and sintering temperature on the physical and electrochemical performance of LiFePO4 powders were investigated.It is noted that Ti4+-doping can improve the electrochemical performance of LiFePO4 remarkably.The Ti4+-doped sample sintered at 600 ℃ delivers an initial discharge capacity of 150,130 and 125 mA·h/g with 0.1C,1C and 2C rates,respectively,without fading after 40 cycles.展开更多
Chemical coprecipitation was used to produce ultrafine and easily sinterable Y2O3-stabilized and （Y2O3,MgO）-stabilized ZrO2 powders. Six precipitation processes for preparation of ZrO2-based ultrafine powders were d...Chemical coprecipitation was used to produce ultrafine and easily sinterable Y2O3-stabilized and （Y2O3,MgO）-stabilized ZrO2 powders. Six precipitation processes for preparation of ZrO2-based ultrafine powders were designed separately, meanwhile different techniques used to control the agglomeration formation were proposed. By means of TEM, SEM, Raman spectroscopy and IR spectroscopy, the mechanisms of agglomeration control in the precipitation processes and post-precipitation and drying process were investigated. The experimental results show that adding appropriate anion surface active agents （such as PAA1460） or polymer （PEG1540 matching with PEG200） in aqueous solution systems during precipitation processes could reinforce charge effect and location effect for gel particles interface. Adding wetting agents to wet gels washing with distilled water during drying process could change interface structure of gel particles and decrease surface tension between gel particles. The agglomeration control in the precipitation, post-precipitation and drying processes had remarkable influence on the characteristics of powders. By adding various macromolecules in the processes, the agglomeration state could be controlled efficiently, and the characteristics of powders were improved.展开更多
Hydroxyapatite(HA) nanoparticles were prepared by coprecipitation-hydrothermal synthesis and their exosyndrome was estimated via transmission electron microscopy. Agarose gel electrophoresis and ultraviolet spectropho...Hydroxyapatite(HA) nanoparticles were prepared by coprecipitation-hydrothermal synthesis and their exosyndrome was estimated via transmission electron microscopy. Agarose gel electrophoresis and ultraviolet spectrophotometry were used to evaluate the ability of HA to bind NR2B-siRNA at different pH values and at different HA-NR2B-siRNA ratios. And the stability of the complex in saline was also evaluated. The effect of HA/NR2B-siRNA complex on chronic inflammatory pain was evaluated in vivo in mice. Transmission electron microscopy(TEM) reveals that HA nanoparticles are thin strips or short rod in shape and the one-dimensional particle size of HA nanoparticles is 40-50 nm. Under the acid or neutral condition, the Zeta potential of HA is positive; nanoparticles can completely bind NR2B-siRNA when the HA:NR2B-siRNA ratio is at or larger than 35-1; while under the alkaline condition, the affinity of HA to NR2B-siRNA is rather weak. HA/NR2B-siRNA complex is not dissociated when being resuspended in saline. The nociception of the tonic phase induced by formalin is significantly reduced in the HA/NR2B-siRNA treated mice as compared with the controls. Therefore, HA may be a new siRNA nano-vector material.展开更多
The effects of potassium addition and the potassium content on the activity and selectivity of coprecipitated iron catalyst for Fischer-Tropsch synthesis （FTS） were studied in a fixed bed reactor at 1.5 MPa, 300 ℃,...The effects of potassium addition and the potassium content on the activity and selectivity of coprecipitated iron catalyst for Fischer-Tropsch synthesis （FTS） were studied in a fixed bed reactor at 1.5 MPa, 300 ℃, and contact time （W/F） of 12.5 gcath/mol using the model bio-oil-syngas of H2/CO/CO2/N2 （62/8/25/5, vol%）. It was found that potassium addition increases the catalyst activity for FTS and the reverse water gas shift reaction. Moreover, potassium increases the average molecular weight （chain length） of the hydrocarbon products. With the increase of potassium content, it was found that CH4 selectivity decreases and the selectivity of liquid phase products （C5＋） increases. The characteristics of FTS catalysts with different potassium content were also investigated by various characterization measurements including X-ray diffraction, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller surface area. Based on experimental results, 100Fe/6Cu/16Al/6K （weight ratio） was selected as the optimal catalyst for FTS from bio-oil-syngas. The results indicate that the 100Fe/6Cu/16Al/6K catalyst is one of the most promising candidates to directly synthesize liquid bio-fuel using bio-oil-syngas.展开更多
文摘Indium tin oxide (ITO) nanoparticles were synthesized by precipitation method from granulated indium and oxalate tin. The ITO particles were characterized by means of XRD, BET and TEM. The tin doping decreases the crystallite size, increases the specific surface area and decreases the lattice volume of the ITO nanoparticles. The absence of chlorine ions in the synthesis greatly increases the particles′ purity, decreases the agglomeration and improves the synthesis efficiency. This synthesis process to ITO nanoparticles is now in pilot-scale production in: Light & Future Advanced Material Co. LTD, Daegu, Korea.
基金Project(2007CB613607) supported by the National Basic Research Program of China
文摘Ti4+-mixed FePO4·xH2O precursor was prepared by co-precipitation method,with which Ti4+ cations were added in the process of preparing FePO4·xH2O to pursue an effective and homogenous doping way.Ti4+-doped LiFePO4 was prepared by an ambient-reduction and post-sintering method using the as-prepared precursor,Li2CO3 and oxalic acid as raw materials.The samples were characterized by scanning electron microscopy (SEM),X-ray diffractometry (XRD),electrochemical impedance spectroscopy (EIS),and electrochemical charge/discharge test.Effects of Ti4+-doping and sintering temperature on the physical and electrochemical performance of LiFePO4 powders were investigated.It is noted that Ti4+-doping can improve the electrochemical performance of LiFePO4 remarkably.The Ti4+-doped sample sintered at 600 ℃ delivers an initial discharge capacity of 150,130 and 125 mA·h/g with 0.1C,1C and 2C rates,respectively,without fading after 40 cycles.
文摘Chemical coprecipitation was used to produce ultrafine and easily sinterable Y2O3-stabilized and （Y2O3,MgO）-stabilized ZrO2 powders. Six precipitation processes for preparation of ZrO2-based ultrafine powders were designed separately, meanwhile different techniques used to control the agglomeration formation were proposed. By means of TEM, SEM, Raman spectroscopy and IR spectroscopy, the mechanisms of agglomeration control in the precipitation processes and post-precipitation and drying process were investigated. The experimental results show that adding appropriate anion surface active agents （such as PAA1460） or polymer （PEG1540 matching with PEG200） in aqueous solution systems during precipitation processes could reinforce charge effect and location effect for gel particles interface. Adding wetting agents to wet gels washing with distilled water during drying process could change interface structure of gel particles and decrease surface tension between gel particles. The agglomeration control in the precipitation, post-precipitation and drying processes had remarkable influence on the characteristics of powders. By adding various macromolecules in the processes, the agglomeration state could be controlled efficiently, and the characteristics of powders were improved.
基金Project(07JJ5035)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2007WK3031)supported by Science and Technology Foundation of Hunan Province,China
文摘Hydroxyapatite(HA) nanoparticles were prepared by coprecipitation-hydrothermal synthesis and their exosyndrome was estimated via transmission electron microscopy. Agarose gel electrophoresis and ultraviolet spectrophotometry were used to evaluate the ability of HA to bind NR2B-siRNA at different pH values and at different HA-NR2B-siRNA ratios. And the stability of the complex in saline was also evaluated. The effect of HA/NR2B-siRNA complex on chronic inflammatory pain was evaluated in vivo in mice. Transmission electron microscopy(TEM) reveals that HA nanoparticles are thin strips or short rod in shape and the one-dimensional particle size of HA nanoparticles is 40-50 nm. Under the acid or neutral condition, the Zeta potential of HA is positive; nanoparticles can completely bind NR2B-siRNA when the HA:NR2B-siRNA ratio is at or larger than 35-1; while under the alkaline condition, the affinity of HA to NR2B-siRNA is rather weak. HA/NR2B-siRNA complex is not dissociated when being resuspended in saline. The nociception of the tonic phase induced by formalin is significantly reduced in the HA/NR2B-siRNA treated mice as compared with the controls. Therefore, HA may be a new siRNA nano-vector material.
基金The authors thank Prof. Yi-lu Fu and Prof. Peiyan Lin for their kind help. This work was supported by the 863 Program （No.2006AA05Z118）, 973 Program （No.2007CB210206）, and the National Natural Science Foundation of China （No.50772107）.
文摘The effects of potassium addition and the potassium content on the activity and selectivity of coprecipitated iron catalyst for Fischer-Tropsch synthesis （FTS） were studied in a fixed bed reactor at 1.5 MPa, 300 ℃, and contact time （W/F） of 12.5 gcath/mol using the model bio-oil-syngas of H2/CO/CO2/N2 （62/8/25/5, vol%）. It was found that potassium addition increases the catalyst activity for FTS and the reverse water gas shift reaction. Moreover, potassium increases the average molecular weight （chain length） of the hydrocarbon products. With the increase of potassium content, it was found that CH4 selectivity decreases and the selectivity of liquid phase products （C5＋） increases. The characteristics of FTS catalysts with different potassium content were also investigated by various characterization measurements including X-ray diffraction, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller surface area. Based on experimental results, 100Fe/6Cu/16Al/6K （weight ratio） was selected as the optimal catalyst for FTS from bio-oil-syngas. The results indicate that the 100Fe/6Cu/16Al/6K catalyst is one of the most promising candidates to directly synthesize liquid bio-fuel using bio-oil-syngas.
