Interfacial properties rhamnolipids from an extract produced by a strain of Pseudomonas aeruginosa were analyzed in this study. The extract of rhamnolipid was characterized by surface tension in different conditions;i...Interfacial properties rhamnolipids from an extract produced by a strain of Pseudomonas aeruginosa were analyzed in this study. The extract of rhamnolipid was characterized by surface tension in different conditions;interfacial tension with different hydrocarbons;critical micelle concentration under different pH and temperatures;particle size and emulsification capacity using laser light profiling. It was observed that the rhamnolipids extract are sensitive to variations in pH, thermostable and function as good emulsificant for emulsification of methyl methacrylate. The emulsion stability order in function of the oil phase was methyl methacrylate > emulsions of castor oil > emulsion n-heptane > emulsion toluene > emulsion hexadecane > octane emulsion. The data presented show that rhamnolipid extracts may be used to formulate stable emulsions of methyl methacrylate. This process can be used to do nano/microsphere of polymethyl methacrylate.展开更多
Rheological properties of microemulsions(MEs) and their printability in three dimensional printing(3DP) systems were investigated.A series of MEs with different contents of oil phase were prepared using sonication met...Rheological properties of microemulsions(MEs) and their printability in three dimensional printing(3DP) systems were investigated.A series of MEs with different contents of oil phase were prepared using sonication method with ibuprofen as model drug and soybean lecithin as emulfier.Stationary and transient rheological properties of MEs were investigated by ARES-SRF using concentric cylinders measuring systems.3DP systems with piezoelectric drop-on-demand print heads were employed to test the printability of the MEs.Results demonstrate that the apparent viscosity and dynamic linear viscoelastic regions of the MEs are the most important parameters for continuous and stable printing of MEs by 3DP.The incorporation of drug in the MEs has little influence on the MEs' stationary rheological behaviors and dynamic viscoelasticity,but the concentration of oil phase has a strong influence on them.The rheological property of binder liquids has a close relationship with their printability in 3DP system.展开更多
Ultrafine γ-A12O3 particles are synthesized in Triton X- 10 0/n - hexanol/cycloh exan e/wat er water in o if(w/o )Inicroemulsion by mixing two separately prepared microemulsions containing Al(NO)3 and (Wb)ZCO, respec...Ultrafine γ-A12O3 particles are synthesized in Triton X- 10 0/n - hexanol/cycloh exan e/wat er water in o if(w/o )Inicroemulsion by mixing two separately prepared microemulsions containing Al(NO)3 and (Wb)ZCO, respectively.The ultrafine Al2O3 particles are characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD)and their size and distribution are measured. The effects of water, surfactallt and reactant concentrations on the particlesize and distribution are studied. The results show that the particle size and distribution can be changed by varying thepreparation conditions, and the size of the microemulsion droplets has a controlling effect on the size of the pafticles. A. possible mechanism of ultrafine particles (UFPs) prepared by microemulsions is proposed.展开更多
Water solubility enhancements of naphthalene(Naph), phenantherene(Phen) and pyrene(Py) in sodium castor oil sulfonate(SCOS) microemulsions were evaluated. The apparent solubilities of PAHs are linearly proportional to...Water solubility enhancements of naphthalene(Naph), phenantherene(Phen) and pyrene(Py) in sodium castor oil sulfonate(SCOS) microemulsions were evaluated. The apparent solubilities of PAHs are linearly proportional to the concentrations of SCOS microemulsion, and the enhancement extent by SCOS solutions is greater than that by ordinary surfactants on the basis of weight solubilization ratio(WSR). The log K em values of Naph, Phen, and Py are 3 13, 4 44 and 5 01 respectively, which are about the same as the log K ow values. At 5000 mg/L of SCOS conccentration, the apparent solubilities are 8 80, 121, and 674 times as the intrinsic solubilities for Naph, Phen, and Py. The effects of inorganic ions and temperature on the solubilization of solutes are also investigated. The solubilization is improved with a moderate addition of Ca 2+ , Na +, NH + 4 and the mixture of Na +, K +, Ca 2+ , Mg 2+ and NH + 4. WSR values are enhanced by 22 0% for Naph, 23 4% for Phen, and 24 6% for Py with temperature increasing by 5℃. The results indicated that SCOS microemulsions improve the performance of the surfactant enhanced remediation(SER) of soil, by increasing solubilities of organic pollutants and reducing the level of surfactant pollution and remediation expenses.展开更多
Supercritical carbon dioxide (scCO 2) microemulsion was formed by supercritical CO 2 , H 2 O, sodium bis(2-ethylhexyl) sulfosuccinate (AOT, surfactant) and C 2 H 5 OH (co-surfactant) under pressures higher than 8 MPa ...Supercritical carbon dioxide (scCO 2) microemulsion was formed by supercritical CO 2 , H 2 O, sodium bis(2-ethylhexyl) sulfosuccinate (AOT, surfactant) and C 2 H 5 OH (co-surfactant) under pressures higher than 8 MPa at 45 oC. The fundamental characteristics of the scCO 2 microemulsion and the minimum miscibility pressure (MMP) with Daqing oil were investigated with a high-pressure falling sphere viscometer, a high-pressure interfacial tension meter, a PVT cell and a slim tube test. The mechanism of the scCO 2 microemulsion for enhancing oil recovery is discussed. The results showed that the viscosity and density of the scCO 2 microemulsion were higher than those of the scCO 2 fluid at the same pressure and temperature. The results of interfacial tension and slim tube tests indicated that the MMP of the scCO 2 microemulsion and crude oil was lower than that of the scCO 2 and crude oil at 45 oC. It is the combined action of viscosity, density and MMP which made the oil recovery efficiency of the scCO 2 microemulsion higher than that of the scCO 2 fluid.展开更多
A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol,catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-...A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol,catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-butanol/cyclohexane/phosphate buffer solution. The restult shows that when the ratio of mol concentration of 1-butanol to 1-hexanoic acid is about 3.0,the initial rate V0 get the maximum values. This phenomenon was explained by the modified fishlike phase diagrams.展开更多
The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), an...The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), and water. The excimer/monomer intensity ratio (Ie/Im) of pyrene has demonstrated that the various structures in the microemulsion phase region can be distinguished. The results are consistent with electrical conductivity data already reported.展开更多
Fouling-resistant ceramic-supported polymer composite membranes were developed for removal of oil-in-water (O/W) microemulsions. The composite membranes were featured with an asymmetric three-layer structure, i.e., a ...Fouling-resistant ceramic-supported polymer composite membranes were developed for removal of oil-in-water (O/W) microemulsions. The composite membranes were featured with an asymmetric three-layer structure, i.e., a porous ceramic membrane substrate, a polyvinylidene fluoride (PVDF) ultrafiltration sub-layer, and a polyam-ide/polyvinyl alcohol (PVA) composite thin top-layer. The PVDF polymer was cast onto the tubular porous ceramic membranes with an immersion precipitation method, and the polyamide/PVA composite thin top-layer was fabricated with an interfacial polymerization method. The effects of the sub-layer composition and the recipe in the interfacial po-lymerization for fabricating the top-layer on the structure and performance of composite membranes were systematically investigated. The prepared composite membranes showed a good performance for treating the O/W microemulsions with a mean diameter of about 2.4μm. At the operating pressure of 0.4MPa, the hydraulic permeability remained steadily about 190L?m-2?h-1, the oil concentration in the permeate was less than 1.6mg·L-1, and the oil rejection coefficient was always higher than 98.5% throughout the operation from the beginning.展开更多
The three-phase behavior in the quaternary system of an alkyl (C8/10- or C12/14-) polyglucoside / 1-butanol / n-octane / water has been studied at 40 ℃ with the modified fishlike phase diagram, which is presented by ...The three-phase behavior in the quaternary system of an alkyl (C8/10- or C12/14-) polyglucoside / 1-butanol / n-octane / water has been studied at 40 ℃ with the modified fishlike phase diagram, which is presented by us for the first time. The mass fraction of 1-butanol in the hydrophile-lipophile balanced interfacial layer, AS, the coordinates of the start point B and the end point E of the phase diagram, and the solubilities of alkyl polyglucoside and 1-butanol in n-octane phase were calculated. The solubilization of the microemulsion was also discussed.展开更多
The dependence of solubilization properties on the alkyl chain length of alkyl glucosides (AG) in AG/isooctane/ n-butanol/water system was investigated. The stable Winsor II system consisting of a water-in-oil (w/o) m...The dependence of solubilization properties on the alkyl chain length of alkyl glucosides (AG) in AG/isooctane/ n-butanol/water system was investigated. The stable Winsor II system consisting of a water-in-oil (w/o) microemulsion phase and an aqueous phase was formed in AG/isooctane/n-butanol/water system. The apparent critical micelle concentration of AG reverse micelles in organic phases was markedly dependent upon the alkyl chain length of AG. The limiting amount of solubilized water increased with an increase in the alkyl chain length of AG. The solubilization capacity of methyl orange (MO) was superior to that of methylene blue (MB), and the solubilization capacities of MO and MB tended to increase with increasing the alkyl chain length of AG. Reverse micelles of dodecyl glucoside (AG12) exhibited the significant solubilization capacities of cytochrome c and lysozyme, while ribonuclease A was not solubilized by AG12 reverse micelles.展开更多
It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2. The phase behavior of SC CO2/Dynol-604/water system was studied. The results showed tha...It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2. The phase behavior of SC CO2/Dynol-604/water system was studied. The results showed that one-phase water-in-CO2 microemulsions could be formed. The solubilization of methyl orange in the microemulsions proved further the existence of water domain in the microemulsions.展开更多
The forming mechanism of microemulsion of sodium dodecyl sulfonate, alcohols, water and isooctane was studied, with particular emphasis on the effect of molecular weight and concentration of alcohols. Phase diagram of...The forming mechanism of microemulsion of sodium dodecyl sulfonate, alcohols, water and isooctane was studied, with particular emphasis on the effect of molecular weight and concentration of alcohols. Phase diagram of the four components, alcohol, sodium dodecyl sulfonate, water and isooctane, was used as a means of study, through which the microemulsion regions were deter-mined. Phase diagram of sodium dodecyl sulfonate/n-pentanol/isooctane/water system at km = 2 (km = Wn-pentanol / WSDS ) is presented. The variation of conductivities of different microemulsion samples with water was measured. From the conductivities we investigated a change in structure from water droplets in oil (W/O) at low water content to liquid crystal at intermediate water content and a struc-ture of oil droplets in water (O/W) at high water content.展开更多
Uniform rice-like CdS particles were synthesized in cyclohexane/Triton X-100/n-pentanol/water quaternary microemulsions. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscop...Uniform rice-like CdS particles were synthesized in cyclohexane/Triton X-100/n-pentanol/water quaternary microemulsions. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, and electron diffraction. The results indicate that the size and the shape of the rice-like CdS particles can be influenced by the molar ratio of water to the surfactant(w value) and the reactant concentrations.展开更多
CuO nanoparticles were synthesized by using microreactors made of Triton X-100/n-hextnol/cyclohexane/water W/O microemulsion system. Basic synthesis parameters were determined. The results of thermo gravimetric/differ...CuO nanoparticles were synthesized by using microreactors made of Triton X-100/n-hextnol/cyclohexane/water W/O microemulsion system. Basic synthesis parameters were determined. The results of thermo gravimetric/differential thermal analysis(TG/DTA) of the precursor products indicated that the proper calcination temperature was about 500 ℃. The nanoparticles were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM) and UV-visible spectra. It was indicated that the grain size was highly dependent on the ratio of water to surfactant(R). With the R value increasing, the particles size became larger.展开更多
After discussion on the mechanism of polymer particle nucleation and growth in inverse microemulsion polymerization, a schematic physical model for polymerization of acrylamide in inverse microemulsions was presented....After discussion on the mechanism of polymer particle nucleation and growth in inverse microemulsion polymerization, a schematic physical model for polymerization of acrylamide in inverse microemulsions was presented. Furthermore, several key problems in mathematically modeling of inverse microemulsion polymerization were pointed out.展开更多
The polymerization of the inverse microemulsions composed of methyl methacrylate,acrylic acid, sodium dodecyl sulfate and water was monitored by refractometer, conductometer andtime-resolved light scattering device. T...The polymerization of the inverse microemulsions composed of methyl methacrylate,acrylic acid, sodium dodecyl sulfate and water was monitored by refractometer, conductometer andtime-resolved light scattering device. The results showed that refractive index, conductivity orintensity distribution of scattered light changed along with polymerization, and different processesof polymerization could be identified.展开更多
The dielectric relaxation spectroscopy (DRS) of Winsor Ⅰ～Ⅲ microemulsions for nonionic surfactant octyl polyglucoside C8G1.46/1-butanol/cyclohexane/water system was studied.The experiment shows that the permittivit...The dielectric relaxation spectroscopy (DRS) of Winsor Ⅰ～Ⅲ microemulsions for nonionic surfactant octyl polyglucoside C8G1.46/1-butanol/cyclohexane/water system was studied.The experiment shows that the permittivity decreases with the increase in the frequency and clear dielectric relaxation phenomena were observed. Permittivity obviously decreases with the change of the microstructure of the microemulsion, W/O, B.C. and O/W can be distinguished by the permittivity.展开更多
Microemulsions are promising drug delivery systems for the oral administration of poorly watersoluble drugs. However, the evolution of microemulsions in the gastrointestinal tract is still poorly characterized,especia...Microemulsions are promising drug delivery systems for the oral administration of poorly watersoluble drugs. However, the evolution of microemulsions in the gastrointestinal tract is still poorly characterized,especially the structural change of microemulsions under the effect of lipase and mucus. To better understand the fate of microemulsions in the gastrointestinal tract, we applied small-angle X-ray scattering(SAXS) and fluorescence resonance energy transfer(FRET) to monitor the structural change of microemulsions under the effect of lipolysis and mucus. First, the effect of lipolysis on microemulsions was studied by SAXS, which found the generation of liquid crystalline phases. Meanwhile, FRET spectra indicated micelles with smaller particle sizes were generated during lipolysis, which could be affected by CaCl_2, bile salts and lecithin. Then, the effect of mucus on the structural change of lipolysed microemulsions was studied. The results of SAXS and FRET indicated that the liquid crystalline phases disappeared, and more micelles were generated. In summary, we studied the structural change of microemulsions in simulated gastrointestinal conditions by SAXS and FRET, and successfully monitored the appearance and disappearance of the liquid crystalline phases and micelles.展开更多
文摘Interfacial properties rhamnolipids from an extract produced by a strain of Pseudomonas aeruginosa were analyzed in this study. The extract of rhamnolipid was characterized by surface tension in different conditions;interfacial tension with different hydrocarbons;critical micelle concentration under different pH and temperatures;particle size and emulsification capacity using laser light profiling. It was observed that the rhamnolipids extract are sensitive to variations in pH, thermostable and function as good emulsificant for emulsification of methyl methacrylate. The emulsion stability order in function of the oil phase was methyl methacrylate > emulsions of castor oil > emulsion n-heptane > emulsion toluene > emulsion hexadecane > octane emulsion. The data presented show that rhamnolipid extracts may be used to formulate stable emulsions of methyl methacrylate. This process can be used to do nano/microsphere of polymethyl methacrylate.
基金Project(B07024) supported by Biomedical Textile Materials "111 Project" from Ministry of Education of ChinaProject(50773009) supported by the National Natural Science Foundation of ChinaProject(Grant IRT0526) supported by Program for Changjiang Scholars and Innovative Research Team in University
文摘Rheological properties of microemulsions(MEs) and their printability in three dimensional printing(3DP) systems were investigated.A series of MEs with different contents of oil phase were prepared using sonication method with ibuprofen as model drug and soybean lecithin as emulfier.Stationary and transient rheological properties of MEs were investigated by ARES-SRF using concentric cylinders measuring systems.3DP systems with piezoelectric drop-on-demand print heads were employed to test the printability of the MEs.Results demonstrate that the apparent viscosity and dynamic linear viscoelastic regions of the MEs are the most important parameters for continuous and stable printing of MEs by 3DP.The incorporation of drug in the MEs has little influence on the MEs' stationary rheological behaviors and dynamic viscoelasticity,but the concentration of oil phase has a strong influence on them.The rheological property of binder liquids has a close relationship with their printability in 3DP system.
文摘Ultrafine γ-A12O3 particles are synthesized in Triton X- 10 0/n - hexanol/cycloh exan e/wat er water in o if(w/o )Inicroemulsion by mixing two separately prepared microemulsions containing Al(NO)3 and (Wb)ZCO, respectively.The ultrafine Al2O3 particles are characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD)and their size and distribution are measured. The effects of water, surfactallt and reactant concentrations on the particlesize and distribution are studied. The results show that the particle size and distribution can be changed by varying thepreparation conditions, and the size of the microemulsion droplets has a controlling effect on the size of the pafticles. A. possible mechanism of ultrafine particles (UFPs) prepared by microemulsions is proposed.
文摘Water solubility enhancements of naphthalene(Naph), phenantherene(Phen) and pyrene(Py) in sodium castor oil sulfonate(SCOS) microemulsions were evaluated. The apparent solubilities of PAHs are linearly proportional to the concentrations of SCOS microemulsion, and the enhancement extent by SCOS solutions is greater than that by ordinary surfactants on the basis of weight solubilization ratio(WSR). The log K em values of Naph, Phen, and Py are 3 13, 4 44 and 5 01 respectively, which are about the same as the log K ow values. At 5000 mg/L of SCOS conccentration, the apparent solubilities are 8 80, 121, and 674 times as the intrinsic solubilities for Naph, Phen, and Py. The effects of inorganic ions and temperature on the solubilization of solutes are also investigated. The solubilization is improved with a moderate addition of Ca 2+ , Na +, NH + 4 and the mixture of Na +, K +, Ca 2+ , Mg 2+ and NH + 4. WSR values are enhanced by 22 0% for Naph, 23 4% for Phen, and 24 6% for Py with temperature increasing by 5℃. The results indicated that SCOS microemulsions improve the performance of the surfactant enhanced remediation(SER) of soil, by increasing solubilities of organic pollutants and reducing the level of surfactant pollution and remediation expenses.
基金support from the National Natural Science Fund (50904073)the CNPC Science and Technology Innovation Fund (2008D-5006-02-06)
文摘Supercritical carbon dioxide (scCO 2) microemulsion was formed by supercritical CO 2 , H 2 O, sodium bis(2-ethylhexyl) sulfosuccinate (AOT, surfactant) and C 2 H 5 OH (co-surfactant) under pressures higher than 8 MPa at 45 oC. The fundamental characteristics of the scCO 2 microemulsion and the minimum miscibility pressure (MMP) with Daqing oil were investigated with a high-pressure falling sphere viscometer, a high-pressure interfacial tension meter, a PVT cell and a slim tube test. The mechanism of the scCO 2 microemulsion for enhancing oil recovery is discussed. The results showed that the viscosity and density of the scCO 2 microemulsion were higher than those of the scCO 2 fluid at the same pressure and temperature. The results of interfacial tension and slim tube tests indicated that the MMP of the scCO 2 microemulsion and crude oil was lower than that of the scCO 2 and crude oil at 45 oC. It is the combined action of viscosity, density and MMP which made the oil recovery efficiency of the scCO 2 microemulsion higher than that of the scCO 2 fluid.
文摘A novel kinetic mechanism of esterification reaction of 1-hexanoic acid with 1-butanol,catalyzed by lipase, was studied in water-in-oil microemulsions. The microemulsions were formed by alkyl polyglucoside C10G1.54/1-butanol/cyclohexane/phosphate buffer solution. The restult shows that when the ratio of mol concentration of 1-butanol to 1-hexanoic acid is about 3.0,the initial rate V0 get the maximum values. This phenomenon was explained by the modified fishlike phase diagrams.
基金the Science Foundation of Shandong University for the Youth (y34029) and the National Natural Science Foundation of China (29903006).
文摘The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), and water. The excimer/monomer intensity ratio (Ie/Im) of pyrene has demonstrated that the various structures in the microemulsion phase region can be distinguished. The results are consistent with electrical conductivity data already reported.
基金Supported by the Trans-century Training Programme Foundation for the Talents by the Ministry of Education of China (No.2002-48).
文摘Fouling-resistant ceramic-supported polymer composite membranes were developed for removal of oil-in-water (O/W) microemulsions. The composite membranes were featured with an asymmetric three-layer structure, i.e., a porous ceramic membrane substrate, a polyvinylidene fluoride (PVDF) ultrafiltration sub-layer, and a polyam-ide/polyvinyl alcohol (PVA) composite thin top-layer. The PVDF polymer was cast onto the tubular porous ceramic membranes with an immersion precipitation method, and the polyamide/PVA composite thin top-layer was fabricated with an interfacial polymerization method. The effects of the sub-layer composition and the recipe in the interfacial po-lymerization for fabricating the top-layer on the structure and performance of composite membranes were systematically investigated. The prepared composite membranes showed a good performance for treating the O/W microemulsions with a mean diameter of about 2.4μm. At the operating pressure of 0.4MPa, the hydraulic permeability remained steadily about 190L?m-2?h-1, the oil concentration in the permeate was less than 1.6mg·L-1, and the oil rejection coefficient was always higher than 98.5% throughout the operation from the beginning.
文摘The three-phase behavior in the quaternary system of an alkyl (C8/10- or C12/14-) polyglucoside / 1-butanol / n-octane / water has been studied at 40 ℃ with the modified fishlike phase diagram, which is presented by us for the first time. The mass fraction of 1-butanol in the hydrophile-lipophile balanced interfacial layer, AS, the coordinates of the start point B and the end point E of the phase diagram, and the solubilities of alkyl polyglucoside and 1-butanol in n-octane phase were calculated. The solubilization of the microemulsion was also discussed.
文摘The dependence of solubilization properties on the alkyl chain length of alkyl glucosides (AG) in AG/isooctane/ n-butanol/water system was investigated. The stable Winsor II system consisting of a water-in-oil (w/o) microemulsion phase and an aqueous phase was formed in AG/isooctane/n-butanol/water system. The apparent critical micelle concentration of AG reverse micelles in organic phases was markedly dependent upon the alkyl chain length of AG. The limiting amount of solubilized water increased with an increase in the alkyl chain length of AG. The solubilization capacity of methyl orange (MO) was superior to that of methylene blue (MB), and the solubilization capacities of MO and MB tended to increase with increasing the alkyl chain length of AG. Reverse micelles of dodecyl glucoside (AG12) exhibited the significant solubilization capacities of cytochrome c and lysozyme, while ribonuclease A was not solubilized by AG12 reverse micelles.
基金The authors are grateful to the National Natural Science Foundation of China and Ministry of Science and Technology for the financial support(29725308,G20000781).
文摘It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2. The phase behavior of SC CO2/Dynol-604/water system was studied. The results showed that one-phase water-in-CO2 microemulsions could be formed. The solubilization of methyl orange in the microemulsions proved further the existence of water domain in the microemulsions.
基金Supported by the Natural Science Foundation of Zhejiang Province (No. 299018).
文摘The forming mechanism of microemulsion of sodium dodecyl sulfonate, alcohols, water and isooctane was studied, with particular emphasis on the effect of molecular weight and concentration of alcohols. Phase diagram of the four components, alcohol, sodium dodecyl sulfonate, water and isooctane, was used as a means of study, through which the microemulsion regions were deter-mined. Phase diagram of sodium dodecyl sulfonate/n-pentanol/isooctane/water system at km = 2 (km = Wn-pentanol / WSDS ) is presented. The variation of conductivities of different microemulsion samples with water was measured. From the conductivities we investigated a change in structure from water droplets in oil (W/O) at low water content to liquid crystal at intermediate water content and a struc-ture of oil droplets in water (O/W) at high water content.
文摘Uniform rice-like CdS particles were synthesized in cyclohexane/Triton X-100/n-pentanol/water quaternary microemulsions. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, and electron diffraction. The results indicate that the size and the shape of the rice-like CdS particles can be influenced by the molar ratio of water to the surfactant(w value) and the reactant concentrations.
基金Funded by the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20132124120003)
文摘CuO nanoparticles were synthesized by using microreactors made of Triton X-100/n-hextnol/cyclohexane/water W/O microemulsion system. Basic synthesis parameters were determined. The results of thermo gravimetric/differential thermal analysis(TG/DTA) of the precursor products indicated that the proper calcination temperature was about 500 ℃. The nanoparticles were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM) and UV-visible spectra. It was indicated that the grain size was highly dependent on the ratio of water to surfactant(R). With the R value increasing, the particles size became larger.
基金ChinaSklochePolymerReactionEngineeringLaboratory (No .KF990 4)FujianProvincialNaturalScienceFoundationofChina(No .D0 0 10 0 0 4)
文摘After discussion on the mechanism of polymer particle nucleation and growth in inverse microemulsion polymerization, a schematic physical model for polymerization of acrylamide in inverse microemulsions was presented. Furthermore, several key problems in mathematically modeling of inverse microemulsion polymerization were pointed out.
基金the National Natural Science Foundation of China （No.20304001）.
文摘The polymerization of the inverse microemulsions composed of methyl methacrylate,acrylic acid, sodium dodecyl sulfate and water was monitored by refractometer, conductometer andtime-resolved light scattering device. The results showed that refractive index, conductivity orintensity distribution of scattered light changed along with polymerization, and different processesof polymerization could be identified.
基金This project is supported by the Natural Science Foundation of Shandong Province(No:Y2003B01).
文摘The dielectric relaxation spectroscopy (DRS) of Winsor Ⅰ～Ⅲ microemulsions for nonionic surfactant octyl polyglucoside C8G1.46/1-butanol/cyclohexane/water system was studied.The experiment shows that the permittivity decreases with the increase in the frequency and clear dielectric relaxation phenomena were observed. Permittivity obviously decreases with the change of the microstructure of the microemulsion, W/O, B.C. and O/W can be distinguished by the permittivity.
基金supported by the National Natural Science Foundation of China (Grant No. 81703606)the Educational Committee Foundation of Liaoning Province (Grant No. L2016026)the Fundamental Research Funds for the Central Universities (Grant no. wd01185)
文摘Microemulsions are promising drug delivery systems for the oral administration of poorly watersoluble drugs. However, the evolution of microemulsions in the gastrointestinal tract is still poorly characterized,especially the structural change of microemulsions under the effect of lipase and mucus. To better understand the fate of microemulsions in the gastrointestinal tract, we applied small-angle X-ray scattering(SAXS) and fluorescence resonance energy transfer(FRET) to monitor the structural change of microemulsions under the effect of lipolysis and mucus. First, the effect of lipolysis on microemulsions was studied by SAXS, which found the generation of liquid crystalline phases. Meanwhile, FRET spectra indicated micelles with smaller particle sizes were generated during lipolysis, which could be affected by CaCl_2, bile salts and lecithin. Then, the effect of mucus on the structural change of lipolysed microemulsions was studied. The results of SAXS and FRET indicated that the liquid crystalline phases disappeared, and more micelles were generated. In summary, we studied the structural change of microemulsions in simulated gastrointestinal conditions by SAXS and FRET, and successfully monitored the appearance and disappearance of the liquid crystalline phases and micelles.
