Papers by Keyword: Microemulsion

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Authors: Hai Ke Feng
Abstract: In this paper, we present a novel embed fluorescence method that allows one to monitor the change from emulsion polymerization to microemulsion polymerization with low monomer contents. The microemulsion polymerization of methyl methacrylate (MMA) was investigated using N-(2-anthracene) methacrylamide (AnMA) as the probe whose fluorescence emission intensity was proportional to the conversion of MMA into the polymer.In this research, the trace amount of AnMA unit looked like embed in the MMA chain. In a solution containing 3wt% of MMA with respect to water, with the anionic surfactant of sodium dodecyl sulphate (SDS) and water-soluble initiator of potassium persulfate (KPS), the process of changing from emulsion to microemulsion has been monitored. By contrast, with the non-ionic surfactant of polyoxyethylene (20) oleyl ether (Brij98) or water-insoluble initiator of 2,2′-azobis(isobutyronitrile) (AIBN), the process of changing from emulsion to microemulsion also have been monitored.
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Authors: Hua Tian, Jun Hui He, Lin Lin Liu
Abstract: Microporous manganese oxide in the form of laminar octahedral compounds (birnessite) has been synthesized facilely in a microemulsion system consisting of benzyl alcohol (BA), sodium dodecyl sulfate (SDS) and water. BA also served as a reducing reagent in the formation of manganese oxides. The products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Braunauer-Emmett-Teller (BET) measurements. The experimental results indicated that the reaction duration, temperature, and weight ratio of BA/SDS/H2O played key roles in determining the final morophologies of manganese oxide nanomaterials and also in their crystalline phase. Lower process temperature, shorter reaction time and lower BA ratio in the microemulsion were favorable for the formation of birnessite single phase. Mn3O4 nanocrystals appeared at a relatively higher temperature and more BA amount.
485
Authors: Hong Wei, Gang Lu, Yi Chen Lu, Zheng Fu
Abstract: A new O/W microemulsion system for transdermal matrine delivery was developed in order to improve the skin permeability and solubility of matrine. Various factors were investigated including solubility of matrine,the skin permeability of matrine aiming to choose suitable surfactants, cosurfactants and oils. By drawing the pseudo-ternary phase diagrams, the basic prescription of microemulsion were determined. A simplex lattice experiment design was adopted to optimize the composition of microemulsions.The mathematical software Matlab be used to calculate the predicted values to determine the optimization of microemulsion formulation.
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Authors: Fa Mei Feng, Jia Qing Xie, Li Ke Zou, Bin Xie
Abstract: Well-dispersed CeO2 nanoparticles were successfully prepared in a simple system composed of sodium bis (2-ethylhexyl) sulfosuccinate (AOT)- octane-water (W/O) microemulsion in this paper. The morphology and microstructure of the products were characterized by the laser particle size analyzer, Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometer (XRD), differential scanning calorimeter (DSC) and transmission electron microscope (TEM). It was found that the CeO2 nanoparticles obtained from this method have well-proportioned size distributions; the surfactant (AOT) molecule was adsorbed on the surface of CeO2 nanoparticles precursor, which is favorable for the dispersion of CeO2 nanoparticles; the CeO2 nanoparticles calcined was a crystal of the cubic structure. In addition, the mechanism on the formation of the CeO2 nanoparticles was also proposed in this paper.
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Authors: Du Shu Huang, Jin Hong Yin, Xian Shu Lv, Yan Xu, Jie Wu
Abstract: The extraction process of cobalt using microemulsion system saponified with P507 as extracting agent was studied. The influences of initial concentration, the concentration of P507, initial pH, the extracting time and the volume ratio of organic phase to water phase on extraction coefficient were also studied. Experimental results show that the saponification microemulsion system using P507 as extractant is thermodynamic stable, and it can separate cobalt better. The optimum conditions were achieved as: the initial concentration is 0.04 mol/L, pH is 2; The concentration of P507 is 6%, extraction time is 6 min; The volume ratio of organic phase to water phase is 1.5:1.
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Authors: Du Shu Huang, Jin Gang Yu, Rui Min Xiao, Zi Jing Li, Li Da Sun
Abstract: The extraction process of cobalt using microemulsion system saponified with P204 as extracting agent was studied. The influence of initial concentration, the concentration of P204, initial pH, the extracting time and the concentration of cobalt and nickel on extraction coefficient were also studied. Experimental results show that the saponification microemulsion system using P204 as extractant is thermodynamic stable, and it can separate cobalt better. The optimum conditions were achieved as: the initial concentration is 0.05 mol/L, pH is 2; The concentration of P204 is 10%, extraction time is 10 min; The volume ratio of organic phase to water phase is 2:1.
407
Authors: Xin He, Xing Hua Zhao, Wu Qing Ou Yang
Abstract: The purpose of this study was to explore the potential application of the combination of microemulsion as a topical delivery vehicle in enhancing the absorption and efficacy of tripterygium wilfordii multiglycoside (TWM). Various microemulsion formulations were developed and an optimal microemulsion (TWM-ME),which presented spherical droplets and consisted of RH-40, IPM and water was 27: 3.3: 69.7 by weight. It possessd an average droplet size of 23.6 nm, a low viscosity of (3.56±0.12) mm2•s-1 Zeta electric potential was (–5.35±0.42) mV, refractive index was (1.3617±0.0051) nD20, conductivity was (97.6±3.6) μs/cm. Compared to the control solution, TWM-ME provided better skin permeability in vitro. Moreover, TWM-ME has noticeable anti-inflammatory and immune suppression effect. These results indicate that the combination of microemulsion represents an effective vehicle for topical delivery of TWM.
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Authors: Y.C. Chen, Y.G. Zhang
Abstract: BaF2 nanorods were synthesized by hydrothermal microemulsion method using sodium fluoride (NaF) and barium chloride (BaCl2) as the raw materials. The as-prepared products were characterized by powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM). The results showed that the products were composed of BaF2 nanorods with diameters of 18-62 nm and lengths up to 1μm. A directed aggregation growth process mediated by the microemulsion droplet building blocks is proposed for the formation of BaF2 nanorods. Further work is in progress to evaluate the possibility of synthesizing other fluoride 1D nanostructures using a similar method.
441
Authors: Natthida Pakpayat, Prapaporn Boonme
Abstract: This study aimed to develop green microemulsions (MEs) for loading coenzyme Q10 (CoQ10). Decylglucoside, a surfactant in the group of alkyl polyglycosides (APG), was used in the formulations since it is biodegradable and non-ionic, leading to low toxic products and friendly properties to the environment. Two blank MEs, i.e., M1 and M2 were prepared by simple mixing dicaprylyl ether, decylglucoside, sorbotan monolaurate and water in the concentrations of 70%, 2.5%, 22.5% and 5%, respectively for M1 and 60%, 6%, 24% and 10%, respectively for M2. Afterwards, M1 and M2 were incorporated with 5% CoQ10 to obtained QM1 and QM2, respectively. All samples were studied for physicochemical properties and stability under accelerated condition. It was found that they were transparence and absence of liquid crystals. Their rheological profiles indicated low viscosity and Newtonian flow. After stability test by freeze thaw for 5 cycles, physicochemical properties of M1, M2, QM1 and QM2 were not obviously different from those at the initial. In addition, more than 97% of label amount of CoQ10 were found in both QM1 and QM2 after stability study. The results indicated that the investigated decylglucoside MEs were suitable systems for incorporation with CoQ10.
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Authors: Chao Li, Shang Long Chen
Abstract: The aim of this work was to evaluate the microemulsification after incomplete digestion as sample preparation procedure for determination of Ca in leisure foods by high resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Microemulsions were prepared with digestive liquor and n-butyl alcohol as an auxiliary emulsifier after incomplete digestion treatment. The appropriate fuel flow, 70 L/h, and the optimum burner height, 5 mm, were obtained by single factor experimental design. The results showed that the correlation coefficient was better than 0.999, the characteristic concentration was 0.086 mg/L, the precision (RSD) for 6 replicate measurements of Ca was 1.7% and the average of recoveries was 102.1%. F-test and t-test (95% confidence level) in between the proposed method and the comparative method, using microwave digestion-HR-CS FAAS, had no significant difference. Therefore, the proposed method was accurate and stable with a high practical value. It provided scientific basis for determination of metal elements in food.
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