The Experts below are selected from a list of 450 Experts worldwide ranked by ideXlab platform
J L C Fonseca - One of the best experts on this subject based on the ideXlab platform.
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temperature and composition effects on the morphology of o w dispersions based on poly oxyethylene 20 Sorbitan Monolaurate and Sorbitan Monolaurate
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018Co-Authors: Leticia Streck, A L P F Caroni, J L C FonsecaAbstract:Abstract Phase behavior of colloidal systems containing oleic acid, poly(oxyethylene 20) Sorbitan Monolaurate, Sorbitan Monolaurate, and water were studied as a function of composition and temperature. The pseudo-ternary diagram of the resultant dispersions showed the presence of regions related to the occurrence of microemulsions, gel microemulsions, high viscosity emulsions, and low viscosity emulsions. SAXS indicated that compositions with surfactant contents above 50% presented lamellar structures. The same technique was used to detect that this structure was destroyed at 45 °C for systems with oleic acid contents of 10%, while dispersions with 1.5, 2, and 5% of oleic acid did not have their lamellar structure disrupted at this temperature. It indicated that, at the highest oleic acid content used in this work, non-ionic surfactants tended to interact with each other, destroying lamellar structure and promoting cloud point-related phenomena, as indicated by turbidimetry and DLS.
Yukitaka Kimura - One of the best experts on this subject based on the ideXlab platform.
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microfluidic and hydrothermal preparation of vesicles using Sorbitan Monolaurate polyoxyethylene 20 Sorbitan Monolaurate span 20 tween 20
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Toshinori Shimanouchi, Tetsuya Hayashi, Kazuki Toramoto, Saki Fukuma, Keita Hayashi, Kazuma Yasuhara, Yukitaka KimuraAbstract:Abstract Here, we present a method for preparing vesicles by combining hydrothermal emulsification with solvent diffusion (SD). The Sorbitan Monolaurate/polyoxyethylene (20) Sorbitan Monolaurate (Span 20/Tween 20) system was used as the target lipid because these lipids are cheap and advantageous for the production scale. The water-in-oil (W/O) emulsion stabilized with lipids was formed under hydrothermal conditions (240 °C under 10 MPa), followed by mixing with water that included lipids to obtain a W/O-in-water (W/O/W) emulsion. The SD for the W/O/W emulsion as a subsequent process yielded vesicles. The optimal preparation conditions were 50:50 wt% Span 20/Tween 20 as a mixing ratio (final lipid concentration 12 mM), octanoic acid as an organic solvent, 240 °C for 4 min during the hydrothermal treatment, and 4 °C for 24 h in the SD process. The diameter of the vesicles obtained was at most 100 nm, which was comparable to that of the W/O/W emulsion before SD. This suggested that the W/O/W emulsion acted as a template for vesicle formation. The number density, diameter, and membrane properties of vesicles depend on the mixing ratio of the water/oil/lipid system. Specifically, the number density of vesicles was low relative to that of vesicles prepared by the conventional method.
Leticia Streck - One of the best experts on this subject based on the ideXlab platform.
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temperature and composition effects on the morphology of o w dispersions based on poly oxyethylene 20 Sorbitan Monolaurate and Sorbitan Monolaurate
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2018Co-Authors: Leticia Streck, A L P F Caroni, J L C FonsecaAbstract:Abstract Phase behavior of colloidal systems containing oleic acid, poly(oxyethylene 20) Sorbitan Monolaurate, Sorbitan Monolaurate, and water were studied as a function of composition and temperature. The pseudo-ternary diagram of the resultant dispersions showed the presence of regions related to the occurrence of microemulsions, gel microemulsions, high viscosity emulsions, and low viscosity emulsions. SAXS indicated that compositions with surfactant contents above 50% presented lamellar structures. The same technique was used to detect that this structure was destroyed at 45 °C for systems with oleic acid contents of 10%, while dispersions with 1.5, 2, and 5% of oleic acid did not have their lamellar structure disrupted at this temperature. It indicated that, at the highest oleic acid content used in this work, non-ionic surfactants tended to interact with each other, destroying lamellar structure and promoting cloud point-related phenomena, as indicated by turbidimetry and DLS.
Toshinori Shimanouchi - One of the best experts on this subject based on the ideXlab platform.
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microfluidic and hydrothermal preparation of vesicles using Sorbitan Monolaurate polyoxyethylene 20 Sorbitan Monolaurate span 20 tween 20
Colloids and Surfaces B: Biointerfaces, 2021Co-Authors: Toshinori Shimanouchi, Tetsuya Hayashi, Kazuki Toramoto, Saki Fukuma, Keita Hayashi, Kazuma Yasuhara, Yukitaka KimuraAbstract:Abstract Here, we present a method for preparing vesicles by combining hydrothermal emulsification with solvent diffusion (SD). The Sorbitan Monolaurate/polyoxyethylene (20) Sorbitan Monolaurate (Span 20/Tween 20) system was used as the target lipid because these lipids are cheap and advantageous for the production scale. The water-in-oil (W/O) emulsion stabilized with lipids was formed under hydrothermal conditions (240 °C under 10 MPa), followed by mixing with water that included lipids to obtain a W/O-in-water (W/O/W) emulsion. The SD for the W/O/W emulsion as a subsequent process yielded vesicles. The optimal preparation conditions were 50:50 wt% Span 20/Tween 20 as a mixing ratio (final lipid concentration 12 mM), octanoic acid as an organic solvent, 240 °C for 4 min during the hydrothermal treatment, and 4 °C for 24 h in the SD process. The diameter of the vesicles obtained was at most 100 nm, which was comparable to that of the W/O/W emulsion before SD. This suggested that the W/O/W emulsion acted as a template for vesicle formation. The number density, diameter, and membrane properties of vesicles depend on the mixing ratio of the water/oil/lipid system. Specifically, the number density of vesicles was low relative to that of vesicles prepared by the conventional method.
B W Brooks - One of the best experts on this subject based on the ideXlab platform.
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phase inversion in p xylene water emulsions with the non ionic surfactant pair Sorbitan Monolaurate polyoxyethylene Sorbitan Monolaurate span 20 tween 20
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2003Co-Authors: Shahriar Sajjadi, M Zerfa, B W BrooksAbstract:Abstract Phase inversion behaviour of a model oil–water emulsion, p-xylene–water, with Span 20/Tween 20 as a surfactant set was investigated. The surfactant hydrophilic-lipophilic balance (HLB), p-xylene/water ratio, and the addition policy were varied for different surfactant concentrations. The morphology of the resulting emulsions was recorded, and maps for different surfactant concentrations were developed. The ‘transitional’ inversion was irreversible and the inversion boundary was found to be discontinuous and was only observed at a high dispersed-phase ratio. No transitional inversion was recorded for the middle range of dispersed phase ratio whatever the type of emulsion was. The transitional inversion boundaries became wider with increasing surfactant concentration. An interaction between catastrophic and transitional inversion boundaries was found for the Span 20/Tween 20 system. The transitional inversion occurred only if, according to the catastrophic inversion boundaries, there is only one morphology possible for the inverted emulsion. The discontinuity in the transitional inversion boundary and the fact that its existence depended on the direction of HLB change and water/oil ratio are uncharacteristic of conventional transitional inversions. However, the drop size and interfacial-tension varied with the surfactant HLB and both decreased to a minimum value at the potential inversion boundary, even though the inversion did not occur, similar to the trend generally observed for a conventional transitional phase inversion. The results suggest that a minimum in drop size, together with a minimum in the interfacial tension, does not necessarily lead to a phase inversion.