The submicroparticles of β-sitosterol were produced by using an aerosol solvent extraction system （ASES） and characterized by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, and Fourier transform...The submicroparticles of β-sitosterol were produced by using an aerosol solvent extraction system （ASES） and characterized by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, and Fourier transform infrared （FT-IR） analysis. The effects of operational parameters including pressure, temperature, solution concentration, and ratio of flow rate （CO2/solution, r） on particle size （PS）, yield, and morphology were investigated. The results showed that microparticles of β-sitosterol （less than 1000 nm size and larger than 70% yield） could be obtained at 10-15 MPa, 35 50℃, 15 mg·ml^-1, 10/1（r）; β-sitosterol particles were found to occur as three mophologies： flakes, rods, and spheres by varying ratio of flow rate or solution concentration. In contrast, the crystallinity of β-sitosterol decreased, whereas its molecular structure remained almost unchanged after being ASES-treated. Therefore, ASES was an effective method to produce submicroparticles of β-sitosterol.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
Lithium-ion conductor Liz.3Alo.3Ti1.7（P04）3 with an ultrapure NASICON-type phase is syn- thesized by a 1,2-propylene glycol （1,2-PG）-assisted sol-gel method and characterized by differential thermal analysis-therm...Lithium-ion conductor Liz.3Alo.3Ti1.7（P04）3 with an ultrapure NASICON-type phase is syn- thesized by a 1,2-propylene glycol （1,2-PG）-assisted sol-gel method and characterized by differential thermal analysis-thermo gravimetric analysis, X-ray diffraction, scanning elec- tron microscopy, electrochemical impedance spectroscopy, and chronoamperornetry test. Due to the use of 1,2-PG, a homogeneous and light yellow transparent precursor solu- tion is obtained without the precipitation of Ti4＋ and A13＋ with PO43- Well crystallized Lil.3Alo.3Til.7（PO4）3 can be prepared at much lower temperatures from 850 ~C to 950 ~C within a shorter synthesis time compared with that prepared at a temperature above 1000 ~C by a conventional solid-state reaction method. The lithium ionic conductivity of the sintered pellets is up to 0.3 mS/cm at 50 ℃ with an activation energy as low as 36.6 k J/tool for the specimen pre-sintered at 700 ℃ and sintered at 850 ℃. The high conductivity, good chemi- cal stability and easy fabrication of the Li1.3Al0.3Ti1.7（PO4）a provide a promising candidate as solid electrolyte for all-solid-state Li-ion rechargeable batteries.展开更多
SnS-C composite powders were prepared through one-pot spray pyrolysis for use as anode materials for Na-ion batteries. C microspheres with uniformly attached cubic-like SnS nanocrystals, which have an amorphous C coat...SnS-C composite powders were prepared through one-pot spray pyrolysis for use as anode materials for Na-ion batteries. C microspheres with uniformly attached cubic-like SnS nanocrystals, which have an amorphous C coating layer, were formed at a preparation temperature of 900 ℃. The initial discharge capacities of the bare SnS and SnS-C composite powders at a current density of 500 mA·g^-1 were 695 and 740 mA·h·g^-1, respectively. The discharge capacities after 50 cycles and the capacity retentions measured from the second cycle of the bare SnS and SnS-C composite powders were 25 and 433 mA.h.g-1 and 5 and 89%, respectively. The prepared SnS-C composite powders with high reversible capacities and good cycle performance can be used as Na-ion battery anode materials.展开更多
基金Supported by Shanghai Special Foundation on Nanomaterials(0243nm305)the National High Technology Research and Development Program of China(2007AA10Z350)
文摘The submicroparticles of β-sitosterol were produced by using an aerosol solvent extraction system （ASES） and characterized by scanning electronic microscope （SEM）, X-ray diffraction （XRD）, and Fourier transform infrared （FT-IR） analysis. The effects of operational parameters including pressure, temperature, solution concentration, and ratio of flow rate （CO2/solution, r） on particle size （PS）, yield, and morphology were investigated. The results showed that microparticles of β-sitosterol （less than 1000 nm size and larger than 70% yield） could be obtained at 10-15 MPa, 35 50℃, 15 mg·ml^-1, 10/1（r）; β-sitosterol particles were found to occur as three mophologies： flakes, rods, and spheres by varying ratio of flow rate or solution concentration. In contrast, the crystallinity of β-sitosterol decreased, whereas its molecular structure remained almost unchanged after being ASES-treated. Therefore, ASES was an effective method to produce submicroparticles of β-sitosterol.
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.
文摘Lithium-ion conductor Liz.3Alo.3Ti1.7（P04）3 with an ultrapure NASICON-type phase is syn- thesized by a 1,2-propylene glycol （1,2-PG）-assisted sol-gel method and characterized by differential thermal analysis-thermo gravimetric analysis, X-ray diffraction, scanning elec- tron microscopy, electrochemical impedance spectroscopy, and chronoamperornetry test. Due to the use of 1,2-PG, a homogeneous and light yellow transparent precursor solu- tion is obtained without the precipitation of Ti4＋ and A13＋ with PO43- Well crystallized Lil.3Alo.3Til.7（PO4）3 can be prepared at much lower temperatures from 850 ~C to 950 ~C within a shorter synthesis time compared with that prepared at a temperature above 1000 ~C by a conventional solid-state reaction method. The lithium ionic conductivity of the sintered pellets is up to 0.3 mS/cm at 50 ℃ with an activation energy as low as 36.6 k J/tool for the specimen pre-sintered at 700 ℃ and sintered at 850 ℃. The high conductivity, good chemi- cal stability and easy fabrication of the Li1.3Al0.3Ti1.7（PO4）a provide a promising candidate as solid electrolyte for all-solid-state Li-ion rechargeable batteries.
文摘SnS-C composite powders were prepared through one-pot spray pyrolysis for use as anode materials for Na-ion batteries. C microspheres with uniformly attached cubic-like SnS nanocrystals, which have an amorphous C coating layer, were formed at a preparation temperature of 900 ℃. The initial discharge capacities of the bare SnS and SnS-C composite powders at a current density of 500 mA·g^-1 were 695 and 740 mA·h·g^-1, respectively. The discharge capacities after 50 cycles and the capacity retentions measured from the second cycle of the bare SnS and SnS-C composite powders were 25 and 433 mA.h.g-1 and 5 and 89%, respectively. The prepared SnS-C composite powders with high reversible capacities and good cycle performance can be used as Na-ion battery anode materials.
