In explosive research area, one of important trends is to study on the preparation technology of explosive microparticles. A new principle and method based on supercritical anti-solvent (SAS) process is put forward an...In explosive research area, one of important trends is to study on the preparation technology of explosive microparticles. A new principle and method based on supercritical anti-solvent (SAS) process is put forward and discussed for the preparation of explosive micro-particles. The satisfactory micro-particles of explosives can be obtained easily by its particular mechanism of creating micro-particles, and operating conditions at normal temperature. This method is good for further study and development.展开更多
The supercritical fluid crystallization technique is a novel technology for preparing ultrafine particles. This paper introduced the concept and features of the technique with an emphasis on three kinds of supercritic...The supercritical fluid crystallization technique is a novel technology for preparing ultrafine particles. This paper introduced the concept and features of the technique with an emphasis on three kinds of supercritical fluid crystallization techniques, i.e. rapid expansion of supercritical solutions, supercritical fluid anti-solvent and particles from gas saturated solutions Some questions and the prospect of this technique were also discussed.展开更多
Vitamin D3 （VD3） proliposomes （VDP）, consisted of hydrogenated phosphatidycholine （HPC） and VD3, were prepared using supercritical anti-solvent technology （SAS）. The effects of operation conditions （temperatu...Vitamin D3 （VD3） proliposomes （VDP）, consisted of hydrogenated phosphatidycholine （HPC） and VD3, were prepared using supercritical anti-solvent technology （SAS）. The effects of operation conditions （temperature, pressure and components） on the VD3 loading in VDP were studied. At the optimum conditions of pressure of 8.0 MPa, temperature of 45 ℃, and the mass ratio of 15.0% between VD3 and HPC, the VD3 loading reached 12.89%. VD3 liposomes （VDL） were obtained by hydrating VDP and the entrapment efficiency of VD3 in VDL reached 98.5%. The morphology and structure of VDP and VDL were characterized by SEM （scanning electron micro-scope）, TEM （transmission electron microscope） and XRD （X-ray diffractometer）. The structure of VD3 nanoparti-cles in HPC matrix was formed. The size of VDL with an average diameter of about 1μm was determined by dynamic light scattering instrument （DLS）. The results indicated that VDP can be made by SAS and VDL with high entrapment efficiency can be formed easily via the hydration of VDP.展开更多
The nano-crystalline Cu-Ce-Zr-O composite oxides were successfully prepared by the supercritical anti-solvent （SAS） process. The physicochemical properties and catalytic performances were investigated by X-ray diffr...The nano-crystalline Cu-Ce-Zr-O composite oxides were successfully prepared by the supercritical anti-solvent （SAS） process. The physicochemical properties and catalytic performances were investigated by X-ray diffraction （XRD）, Raman spectroscopy, H2 temperature-programmed reduction （H2 -TPR）, oxygen storage capacity （OSC） measurement and catalytic activity evaluation. It was found that Cu2＋ ions incorporated into CeO2 -ZrO2 lattice to form Cu-Ce-Zr-O solid solution associated with the formation of oxygen vacancies. The Cu-Ce-Zr-O catalysts prepared via the SAS process with the Cu content 2.63 mol.% showed the highest OSC index of 636.9 μmol/g. Compared with the samples prepared by impregnation method, Cu doping using SAS process could improve the dispersion of Cu2＋ in the composite oxide, enhance the interaction between Cu2＋ and CeO2-ZrO2 , improve the reducibility of catalyst, and thus improve the OSC performance and increase the catalytic activity for CO oxidation at low temperature.展开更多
Hollow CuO-CeO2-ZrO2nano-particles were prepared with supercritical anti-solvent apparatus by using methanol as sol-vent and supercritical carbon dioxide as anti-solvent. Two key factors （i.e., pressure and temperat...Hollow CuO-CeO2-ZrO2nano-particles were prepared with supercritical anti-solvent apparatus by using methanol as sol-vent and supercritical carbon dioxide as anti-solvent. Two key factors （i.e., pressure and temperature） were investigated to explore the effects of catalyst structure and physic-chemical properties （i.e., morphology, reducing property, oxygen storage capacity and specific surface area）. The resulting materials were characterized with X-ray diffraction （XRD）, high resolution transmission electron micros-copy （HRTEM）, Brunauer-Emmett-Teller （BET）,hydrogen temperature programmed reduction （H2-TPR） and oxygen storage capac-ity （OSC） measurement, respectively. The experimental results showed that lower temperatures promoted production of hollow struc-ture nano-particulates. The particle morphology also changed significantly, i.e. the solid construction was first transferred to hollow structure then back to solid construction. The optimal conditions for obtaining hollow nano-particles were determined at 45 °C, 18.0–24.0 MPa.展开更多
CeO2-ZrO2-Al2O3 ternary oxides were successfully prepared by a green route of supercritical anti-solvent precipitation with supercritical CO2 as anti-solvent and methanol as solvent. The structures and oxygen storage ...CeO2-ZrO2-Al2O3 ternary oxides were successfully prepared by a green route of supercritical anti-solvent precipitation with supercritical CO2 as anti-solvent and methanol as solvent. The structures and oxygen storage capacities of these ternary oxides were characterized by XRD, Raman spectra and oxygen storage capacity measurements. It was found that Al3＋ and Zr4＋ inserted into CeO2 lattice, forming CeO2-ZrO2-Al2O3 solid solution. The concentration of aluminium isopropoxide in the solution affected the concentration of oxygen vacancy and the distortion of oxygen sublattice which were responsible for the oxygen storage capacity. The rapidest oxygen uptake/release rate and maximum total oxygen storage capacity （122.0 mmolO2/molCeO2） were obtained with the aluminitun isopropoxide concentration at 0.2 wt.% in the solution.展开更多
To improve the physicochemical properties of astaxanthin, it was encapsulated in poly (1-lactic acid)(PLLA) using a supercritical anti-solvent (SAS) process with dichloromethane/acetone mixture as the solvent, and sup...To improve the physicochemical properties of astaxanthin, it was encapsulated in poly (1-lactic acid)(PLLA) using a supercritical anti-solvent (SAS) process with dichloromethane/acetone mixture as the solvent, and supercritical CO2 as the anti-solvent. The effects of altering five SAS operating cond让ions, solvent ratio, temperature, pressure, concentration of carrier, and flow rate, on the microstructure of particles were investigated using an orthogonal experimental design. Under the optimal conditions, astaxanthin/PLLA particles were produced with an encapsulation efficiency of 91.5% and a mean particle size of 954.6 nm. SEM images showed that most astaxanthin/PLLA particles were uniform microspheres. FT-IR spectra showed that the chemical structure of astaxanthin was unchanged by the SAS process. The results of chromatic difference, X-ray diffraction, thermogravimetric, and differential scanning calorimetry analyses showed that astaxanthin had been encapsulated in the PLLA matrix in an amorphous state. Overall, astaxanthin/PLLA microspheres greatly enhanced the stability of astaxanthin during storage, and the levels of residual solvents were far lower than the ICH lim让s. This means that astaxanthin/PLLA microspheres prepared using SAS show great potential for use in many food, cosmetic, and pharmaceutical formulations.展开更多
Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological activities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-human immunodeficiency virus, and antimicr...Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological activities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-human immunodeficiency virus, and antimicrobial activity. In this employed to produce the work, a swirl mixer was micronized curcumin with polyvinylpyrrolidone （PVP） by the supercritical antisolvent process to improve the bioavailability of curcumin. The effects of operating parameters such as curcumin/PVP ratio, feed concentration, temperature, pressure, and CO2 flow rate were investigated. The characterization and solubility of particles were determined by using scanning electron microscopy, Fourier Transform Infrared spectroscopy, and ultra-violet-visible spectroscopy. The result shows that the optimal condition for the production of curcumin/PVP particles is at curcumin/PVP ratio of 1：30, feed concentration of 5 mg·mL^-1, temperature of 40 ℃, pressure of 15 MPa, and CO2 flow rate of 15 mL·min^-1. Moreover, the dissolution of curcumin/PVP particles is faster than that of raw curcumin.展开更多
基金Sponsored by the National Science Research Foundation of China(20176003)
文摘In explosive research area, one of important trends is to study on the preparation technology of explosive microparticles. A new principle and method based on supercritical anti-solvent (SAS) process is put forward and discussed for the preparation of explosive micro-particles. The satisfactory micro-particles of explosives can be obtained easily by its particular mechanism of creating micro-particles, and operating conditions at normal temperature. This method is good for further study and development.
文摘The supercritical fluid crystallization technique is a novel technology for preparing ultrafine particles. This paper introduced the concept and features of the technique with an emphasis on three kinds of supercritical fluid crystallization techniques, i.e. rapid expansion of supercritical solutions, supercritical fluid anti-solvent and particles from gas saturated solutions Some questions and the prospect of this technique were also discussed.
基金Supported by the National High Technology Research and Development Program of China （2007AA 10Z350） and the National Natural Science Foundation of China （20976103）.
文摘Vitamin D3 （VD3） proliposomes （VDP）, consisted of hydrogenated phosphatidycholine （HPC） and VD3, were prepared using supercritical anti-solvent technology （SAS）. The effects of operation conditions （temperature, pressure and components） on the VD3 loading in VDP were studied. At the optimum conditions of pressure of 8.0 MPa, temperature of 45 ℃, and the mass ratio of 15.0% between VD3 and HPC, the VD3 loading reached 12.89%. VD3 liposomes （VDL） were obtained by hydrating VDP and the entrapment efficiency of VD3 in VDL reached 98.5%. The morphology and structure of VDP and VDL were characterized by SEM （scanning electron micro-scope）, TEM （transmission electron microscope） and XRD （X-ray diffractometer）. The structure of VD3 nanoparti-cles in HPC matrix was formed. The size of VDL with an average diameter of about 1μm was determined by dynamic light scattering instrument （DLS）. The results indicated that VDP can be made by SAS and VDL with high entrapment efficiency can be formed easily via the hydration of VDP.
基金Project supported by National Natural Science Foundation of China(20976120)Natural Science Foundation of Tianjin(09JCYBJC06200)
文摘The nano-crystalline Cu-Ce-Zr-O composite oxides were successfully prepared by the supercritical anti-solvent （SAS） process. The physicochemical properties and catalytic performances were investigated by X-ray diffraction （XRD）, Raman spectroscopy, H2 temperature-programmed reduction （H2 -TPR）, oxygen storage capacity （OSC） measurement and catalytic activity evaluation. It was found that Cu2＋ ions incorporated into CeO2 -ZrO2 lattice to form Cu-Ce-Zr-O solid solution associated with the formation of oxygen vacancies. The Cu-Ce-Zr-O catalysts prepared via the SAS process with the Cu content 2.63 mol.% showed the highest OSC index of 636.9 μmol/g. Compared with the samples prepared by impregnation method, Cu doping using SAS process could improve the dispersion of Cu2＋ in the composite oxide, enhance the interaction between Cu2＋ and CeO2-ZrO2 , improve the reducibility of catalyst, and thus improve the OSC performance and increase the catalytic activity for CO oxidation at low temperature.
基金supported by the National Natural Science Foundation of China(20976120)Natural Science Foundation of Tianjin(09JCYBJC06200)
文摘Hollow CuO-CeO2-ZrO2nano-particles were prepared with supercritical anti-solvent apparatus by using methanol as sol-vent and supercritical carbon dioxide as anti-solvent. Two key factors （i.e., pressure and temperature） were investigated to explore the effects of catalyst structure and physic-chemical properties （i.e., morphology, reducing property, oxygen storage capacity and specific surface area）. The resulting materials were characterized with X-ray diffraction （XRD）, high resolution transmission electron micros-copy （HRTEM）, Brunauer-Emmett-Teller （BET）,hydrogen temperature programmed reduction （H2-TPR） and oxygen storage capac-ity （OSC） measurement, respectively. The experimental results showed that lower temperatures promoted production of hollow struc-ture nano-particulates. The particle morphology also changed significantly, i.e. the solid construction was first transferred to hollow structure then back to solid construction. The optimal conditions for obtaining hollow nano-particles were determined at 45 °C, 18.0–24.0 MPa.
基金National Natural Science Foundation of China(20976120)the Natural Science Foundation of Tianjin(09JCYBJC06200)
文摘CeO2-ZrO2-Al2O3 ternary oxides were successfully prepared by a green route of supercritical anti-solvent precipitation with supercritical CO2 as anti-solvent and methanol as solvent. The structures and oxygen storage capacities of these ternary oxides were characterized by XRD, Raman spectra and oxygen storage capacity measurements. It was found that Al3＋ and Zr4＋ inserted into CeO2 lattice, forming CeO2-ZrO2-Al2O3 solid solution. The concentration of aluminium isopropoxide in the solution affected the concentration of oxygen vacancy and the distortion of oxygen sublattice which were responsible for the oxygen storage capacity. The rapidest oxygen uptake/release rate and maximum total oxygen storage capacity （122.0 mmolO2/molCeO2） were obtained with the aluminitun isopropoxide concentration at 0.2 wt.% in the solution.
基金Financial support from the National Natural Science Foundation of China (21476086,21776102)China Postdoctoral Science Foundation (No. 2017M612663) is greatly appreciated.
文摘To improve the physicochemical properties of astaxanthin, it was encapsulated in poly (1-lactic acid)(PLLA) using a supercritical anti-solvent (SAS) process with dichloromethane/acetone mixture as the solvent, and supercritical CO2 as the anti-solvent. The effects of altering five SAS operating cond让ions, solvent ratio, temperature, pressure, concentration of carrier, and flow rate, on the microstructure of particles were investigated using an orthogonal experimental design. Under the optimal conditions, astaxanthin/PLLA particles were produced with an encapsulation efficiency of 91.5% and a mean particle size of 954.6 nm. SEM images showed that most astaxanthin/PLLA particles were uniform microspheres. FT-IR spectra showed that the chemical structure of astaxanthin was unchanged by the SAS process. The results of chromatic difference, X-ray diffraction, thermogravimetric, and differential scanning calorimetry analyses showed that astaxanthin had been encapsulated in the PLLA matrix in an amorphous state. Overall, astaxanthin/PLLA microspheres greatly enhanced the stability of astaxanthin during storage, and the levels of residual solvents were far lower than the ICH lim让s. This means that astaxanthin/PLLA microspheres prepared using SAS show great potential for use in many food, cosmetic, and pharmaceutical formulations.
文摘Curcumin is a hydrophobic polyphenol compound exhibiting a wide range of biological activities such as anti-inflammatory, anti-bacterial, anti-fungal, anti-carcinogenic, anti-human immunodeficiency virus, and antimicrobial activity. In this employed to produce the work, a swirl mixer was micronized curcumin with polyvinylpyrrolidone （PVP） by the supercritical antisolvent process to improve the bioavailability of curcumin. The effects of operating parameters such as curcumin/PVP ratio, feed concentration, temperature, pressure, and CO2 flow rate were investigated. The characterization and solubility of particles were determined by using scanning electron microscopy, Fourier Transform Infrared spectroscopy, and ultra-violet-visible spectroscopy. The result shows that the optimal condition for the production of curcumin/PVP particles is at curcumin/PVP ratio of 1：30, feed concentration of 5 mg·mL^-1, temperature of 40 ℃, pressure of 15 MPa, and CO2 flow rate of 15 mL·min^-1. Moreover, the dissolution of curcumin/PVP particles is faster than that of raw curcumin.
