The organic phase extracted from interfacial crud of copper solvent extraction at Dexing Copper Mine was analyzed for its different components by combined gas chromatography mass spectroscopy. It was found that the ma...The organic phase extracted from interfacial crud of copper solvent extraction at Dexing Copper Mine was analyzed for its different components by combined gas chromatography mass spectroscopy. It was found that the main impurities in organic phase were methylnaphthalenes and di methylnaphthalenes which originated from commercial 260# kerosene used as diluent. It was found that the impurities containing diluent was unfavorable to phase disengagement. Methods were suggested to improve diluent properties to prevent stable interfacial emulsion.展开更多
An O / W emulsion non-solvent addition method was used to prepare ethyleellulose (EC) microcapsules of water soluble pharmaceutical (theophylline). The solvent and non-solvent reagents used in this work were toluene a...An O / W emulsion non-solvent addition method was used to prepare ethyleellulose (EC) microcapsules of water soluble pharmaceutical (theophylline). The solvent and non-solvent reagents used in this work were toluene and cyclohexane. The effects of polymer concentration, core wall ratio and particle size on the kinetics as well as the dissolution rate of the drug were investigated. The results show that the dissolution rate increases with the increasing of polymer concentration and core wall ratio. The release of microcapsules prepared with different procedures can be selectively profiled with first order and Higuchi matrix kinetic models.展开更多
The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles co...The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles containing such hydrophilic groups as carbonyl, carboxyl, sulphonyl or acylamine exist in organic phase. Conclusively, Lix984N would degrade gradually during a long-term contact with the acidic aqueous feed and strip reagents. Lix84 and nonylphenol as effective components of Lix984N degraded almost completely after long-term recycling. Lix984N degraded through such reactions as Beck.mann rearrange, hydrolysis and sulphofication. The degradation of Lix984N would deteriorate solvent extraction and disengagement performance, and result in a more stable interracial emulsion.展开更多
The extended DLVO theory was used to analyze the stability of emulsion stabilized by solid particles. It was emphasized that emulsion droplets covered by solid particles behaved as congener solid granules with the sam...The extended DLVO theory was used to analyze the stability of emulsion stabilized by solid particles. It was emphasized that emulsion droplets covered by solid particles behaved as congener solid granules with the same diameter as droplets. The interaction potential energy curves between emulsion droplets stabilized by mica particles in the copper solvent extraction system were calculated. The results show that the effect of hydration repulsive forces are more powerful than that of electrostatic forces on stabilizing droplets for O/W emulsions. The energy barrier between droplets increases dramatically by about 7 × 103 kT when the hydration repulsion is considered.展开更多
Hollow calcium silicate microparticles were prepared by mixing a water-in-oil (W/O) emulsion containing silicate ions in aqueous phase with an oil phase containing a calcium/di-2-ethylhexyl phosphoric acid (D2EHPA) co...Hollow calcium silicate microparticles were prepared by mixing a water-in-oil (W/O) emulsion containing silicate ions in aqueous phase with an oil phase containing a calcium/di-2-ethylhexyl phosphoric acid (D2EHPA) complex. The inorganic precipitation reaction at the oil-water interface was accelerated by using a simple W/O emulsion. Hollow microparticles were obtained when the mole ratio of D2EHPA and calcium in the oil phase was nearly 2:1. The shell formation of the par-ticles depended on the acceleration of the precipitation reaction, which could be accomplished by controlling the concentrations of the calcium and silicate ions.展开更多
Poly(D,L-Lactic-Co-Glycolic Acid) (PLGA) copolymers have been extensively used as controlled-release carriers for many hydrophilic drugs because they are non-toxic, biodegradable, bioavailable, and biocompatible. In g...Poly(D,L-Lactic-Co-Glycolic Acid) (PLGA) copolymers have been extensively used as controlled-release carriers for many hydrophilic drugs because they are non-toxic, biodegradable, bioavailable, and biocompatible. In general, PLGA particles have been produced by a solvent evaporation technique utilizing water-in-oil-in-water (W/O/W) emulsions. However, W/O/W emulsions are unstable, causing the outer and inner aqueous phases to easily fuse during particle preparation. Consequently, a sufficient amount of drug was not encapsulated inside the particles. In this study, we examined a new particle preparation method utilizing a solid-in-oil-in-water (S/O/W) emulsion technique. The advantages of S/O/W emulsions, wherein a surfactant-drug complex disperses into the oil phase, were as follows: 1) leakage of hydrophilic drugs from the emulsions was inhibited, and 2) facile control over the emulsion particle size. Thus, the PLGA particles prepared by this method showed high encapsulation efficiency of drugs and formation of fine particles of submicron size by membrane emulsification were achieved.展开更多
[Objectives]To prepare 20(S)-protopanaxadiol PLGA nanoparticles(20(S)-PPD-PLGA-NPs).[Methods]20(S)-PPD-PLGA-NPs were prepared by emulsion solvent evaporation method,and the optimal formulation was screened by Box-Behn...[Objectives]To prepare 20(S)-protopanaxadiol PLGA nanoparticles(20(S)-PPD-PLGA-NPs).[Methods]20(S)-PPD-PLGA-NPs were prepared by emulsion solvent evaporation method,and the optimal formulation was screened by Box-Behnken experiment with particle size and drug loading as the indicators through single factor experiment,and the drug release in vitro was carried out.[Results]The average diameter of the nanoparticles was(119.60±2.29)nm and the polydispersity index was(0.12±0.02),the size was uniform.The encapsulation efficiency and drug loading of protopanaxadiol were(87.99±1.29)%and(14.86±0.25)%,respectively.[Conclusions]The 20(S)-PPD-PLGA-NPs were successfully prepared by emulsion solvent evaporation method,and the 20(S)-PPD-PLGA-NPs had good stability,to lay a foundation for the study of 20(S)-PPD-PLGA-NPs in vitro and in vivo.展开更多
文摘The organic phase extracted from interfacial crud of copper solvent extraction at Dexing Copper Mine was analyzed for its different components by combined gas chromatography mass spectroscopy. It was found that the main impurities in organic phase were methylnaphthalenes and di methylnaphthalenes which originated from commercial 260# kerosene used as diluent. It was found that the impurities containing diluent was unfavorable to phase disengagement. Methods were suggested to improve diluent properties to prevent stable interfacial emulsion.
文摘An O / W emulsion non-solvent addition method was used to prepare ethyleellulose (EC) microcapsules of water soluble pharmaceutical (theophylline). The solvent and non-solvent reagents used in this work were toluene and cyclohexane. The effects of polymer concentration, core wall ratio and particle size on the kinetics as well as the dissolution rate of the drug were investigated. The results show that the dissolution rate increases with the increasing of polymer concentration and core wall ratio. The release of microcapsules prepared with different procedures can be selectively profiled with first order and Higuchi matrix kinetic models.
基金Project (P1502) supported by Shanghai Leading Academic Discipline
文摘The organic phase separated from the interfacial crud provided by Dexing copper mine in Jiangxi, China, was analyzed by combined gas chromatography-mass spectroscopy. The results show that many kinds of emphiphiles containing such hydrophilic groups as carbonyl, carboxyl, sulphonyl or acylamine exist in organic phase. Conclusively, Lix984N would degrade gradually during a long-term contact with the acidic aqueous feed and strip reagents. Lix84 and nonylphenol as effective components of Lix984N degraded almost completely after long-term recycling. Lix984N degraded through such reactions as Beck.mann rearrange, hydrolysis and sulphofication. The degradation of Lix984N would deteriorate solvent extraction and disengagement performance, and result in a more stable interracial emulsion.
文摘The extended DLVO theory was used to analyze the stability of emulsion stabilized by solid particles. It was emphasized that emulsion droplets covered by solid particles behaved as congener solid granules with the same diameter as droplets. The interaction potential energy curves between emulsion droplets stabilized by mica particles in the copper solvent extraction system were calculated. The results show that the effect of hydration repulsive forces are more powerful than that of electrostatic forces on stabilizing droplets for O/W emulsions. The energy barrier between droplets increases dramatically by about 7 × 103 kT when the hydration repulsion is considered.
文摘Hollow calcium silicate microparticles were prepared by mixing a water-in-oil (W/O) emulsion containing silicate ions in aqueous phase with an oil phase containing a calcium/di-2-ethylhexyl phosphoric acid (D2EHPA) complex. The inorganic precipitation reaction at the oil-water interface was accelerated by using a simple W/O emulsion. Hollow microparticles were obtained when the mole ratio of D2EHPA and calcium in the oil phase was nearly 2:1. The shell formation of the par-ticles depended on the acceleration of the precipitation reaction, which could be accomplished by controlling the concentrations of the calcium and silicate ions.
文摘Poly(D,L-Lactic-Co-Glycolic Acid) (PLGA) copolymers have been extensively used as controlled-release carriers for many hydrophilic drugs because they are non-toxic, biodegradable, bioavailable, and biocompatible. In general, PLGA particles have been produced by a solvent evaporation technique utilizing water-in-oil-in-water (W/O/W) emulsions. However, W/O/W emulsions are unstable, causing the outer and inner aqueous phases to easily fuse during particle preparation. Consequently, a sufficient amount of drug was not encapsulated inside the particles. In this study, we examined a new particle preparation method utilizing a solid-in-oil-in-water (S/O/W) emulsion technique. The advantages of S/O/W emulsions, wherein a surfactant-drug complex disperses into the oil phase, were as follows: 1) leakage of hydrophilic drugs from the emulsions was inhibited, and 2) facile control over the emulsion particle size. Thus, the PLGA particles prepared by this method showed high encapsulation efficiency of drugs and formation of fine particles of submicron size by membrane emulsification were achieved.
文摘[Objectives]To prepare 20(S)-protopanaxadiol PLGA nanoparticles(20(S)-PPD-PLGA-NPs).[Methods]20(S)-PPD-PLGA-NPs were prepared by emulsion solvent evaporation method,and the optimal formulation was screened by Box-Behnken experiment with particle size and drug loading as the indicators through single factor experiment,and the drug release in vitro was carried out.[Results]The average diameter of the nanoparticles was(119.60±2.29)nm and the polydispersity index was(0.12±0.02),the size was uniform.The encapsulation efficiency and drug loading of protopanaxadiol were(87.99±1.29)%and(14.86±0.25)%,respectively.[Conclusions]The 20(S)-PPD-PLGA-NPs were successfully prepared by emulsion solvent evaporation method,and the 20(S)-PPD-PLGA-NPs had good stability,to lay a foundation for the study of 20(S)-PPD-PLGA-NPs in vitro and in vivo.
