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Fantao Meng - One of the best experts on this subject based on the ideXlab platform.
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preparation of uniform sized pla microcapsules by combining shirasu porous glass membrane emulsification technique and multiple emulsion Solvent Evaporation method
Journal of Controlled Release, 2005Co-Authors: Rong Liu, Fantao MengAbstract:Relatively Uniform-sized biodegradable poly(lactide) (PLA) microcapsules were successfully prepared by combining a Shirasu Porous Glass (SPG) membrane emulsification technique and multiple emulsion-Solvent Evaporation method. An aqueous phase containing lysozyme was used as the internal water phase (w1), and PLA and Arlacel 83 were dissolved in a mixture Solvent of dichloromethane (DCM) and toluene which was used as the oil phase (o). These two solutions were emulsified by a homogenizer to form a w1/o primary emulsion. The primary emulsion was permeated through the uniform pores (5.25 microm) of an SPG membrane into the external water phase by the pressure of nitrogen gas to form the uniform w1/o/w2 droplets. Then, the solid polymer microcapsules were obtained by simply evaporating the Solvent. It is necessary to avoid the phase separation of primary emulsion during the SPG membrane emulsification. It was found that when the density difference of the internal water phase and oil phase was reduced to nearly zero and Arlacel 83 was used as the oil emulsifier, the phase separation was not observed within 24 h. The w1/o/w2 emulsion with uniform diameter was obtained only when Arlaecl 83 concentration was limited below 2.5 wt.% based on oil phase. The drug encapsulation efficiency was found to be related to several factors including PLA molecular weight, additive type and its concentration in the internal water phase, the emulsifier type and concentration in the oil phase, the NaCl concentration and the pH value in the external water phase. Comparing with the stirring method, it was found that the size was more uniform and the drug encapsulation efficiency was much higher when the microcapsules were prepared by SPG membrane emulsification technique and the highest drug encapsulation efficiency of 92.20% was obtained. This is the first study to prepare PLA microcapsules by combining an SPG membrane emulsification technique and multiple emulsion-Solvent Evaporation method.
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preparation of uniform sized pla microcapsules by combining shirasu porous glass membrane emulsification technique and multiple emulsion Solvent Evaporation method
Journal of Controlled Release, 2005Co-Authors: Rong Liu, Fantao MengAbstract:Relatively Uniform-sized biodegradable poly(lactide) (PLA) microcapsules were successfully prepared by combining a Shirasu Porous Glass (SPG) membrane emulsification technique and multiple emulsion-Solvent Evaporation method. An aqueous phase containing lysozyme was used as the internal water phase (w(1)), and PLA and Arlacel 83 were dissolved in a mixture Solvent of dichloromethane (DCM) and toluene which was used as the oil phase (o). These two solutions were emulsified by a homogenizer to form a w(1)/o primary emulsion. The primary emulsion was permeated through the uniform pores (5.25 mu m) of an SPG membrane into the external water phase by the pressure of nitrogen gas to form the uniform w(1)/o/w(2) droplets. Then, the solid polymer microcapsules were obtained by simply evaporating the Solvent. It is necessary to avoid the phase separation of primary emulsion during the SPG membrane emulsification. It was found that when the density difference of the internal water phase and oil phase was reduced to nearly zero and Arlacel 83 was used as the oil emulsifier, the phase separation was not observed within 24 h. The w(1)/o/w(2) emulsion with uniform diameter was obtained only when Arlaecl 83 concentration was limited below 2.5 wt.% based on oil phase. The drug encapsulation efficiency was found to be related to several factors including PLA molecular weight, additive type and its concentration in the internal water phase, the emulsifier type and concentration in the oil phase, the NaCl concentration and the pH value in the external water phase. Comparing with the stirring method, it was found that the size was more uniform and the drug encapsulation efficiency was much higher when the microcapsules were prepared by SPG membrane emulsification technique and the highest drug encapsulation efficiency of 92.20% was obtained. This is the first study to prepare PLA microcapsules by combining an SPG membrane emulsification technique and multiple emulsion-Solvent Evaporation method. (c) 2004 Elsevier B.V. All rights reserved.
Yusuke Yamauchi - One of the best experts on this subject based on the ideXlab platform.
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fabrication of mesoporous silica polymer composites through Solvent Evaporation process and investigation of their excellent low thermal expansion property
Physical Chemistry Chemical Physics, 2011Co-Authors: Norihiro Suzuki, Yusuke Yamauchi, Shosuke KibaAbstract:We fabricate mesoporous silica/epoxy polymer composites through a Solvent Evaporation process. The easy penetration of the epoxy polymers into mesopores is achieved by using a diluted polymer solution including a volatile organic Solvent. After the complete Solvent Evaporation, around 90% of the mesopores are estimated to be filled with the epoxy polymer chains. Here we carefully investigate the thermal expansion behavior of the obtained mesoporous silica/polymer composites. Thermal mechanical analysis (TMA) charts revealed that coefficient of linear thermal expansion (CTE) gradually decreases, as the amount of the doped mesoporous silica increases. Compared with spherical silica particle without mesopores, mesoporous silica particles show a greater effect on lowering the CTE values. Interestingly, it is found that the CTE values are proportionally decreased with the decrease of the total amount of the polymers outside the mesopores. These data demonstrate that polymers embedded inside the mesopores become thermally stable, and do not greaty contribute to the thermal expansion behavior of the composites.
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fabrication of a pt film with a well defined hierarchical pore system via Solvent Evaporation mediated direct physical casting
Electrochemistry Communications, 2006Co-Authors: Yusuke Yamauchi, Kazuyuki KurodaAbstract:Abstract We fabricated a well-ordered Pt thin film with a bimodal pore system by combining the modified liquid crystal templating method (Solvent-Evaporation-mediated direct physical casting, SEDPC) with colloidal crystal templating. The direct observation of the film by high-resolution scanning microscopy (HR-SEM) showed the formation of a hierarchical porous structure. The resulting Pt film possesses macropores (ca. 460 nm), interconnected windows (ca. 100 nm), and mesopores (ca. 3–4 nm). Macropore wall consists of small nanoparticles of ca. 3 nm in size. These nanoparticles are interconnected to create mesoporosity. The cyclic voltammogram of the resulting Pt film in sulfuric acid revealed a typical feature which can identify the clean Pt surface.
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development of microfabrication process of mesoporous pt via Solvent Evaporation mediated direct physical casting selective deposition into sloped microchannels
Science and Technology of Advanced Materials, 2006Co-Authors: Yusuke Yamauchi, Hiroki Kitoh, Toshiyuki Momma, Tetsuya Osaka, Kazuyuki KurodaAbstract:AbstractWe have developed an excellent process for selective deposition of mesoporous Pt through tailored microfabrication steps via the “Solvent-Evaporation-mediated Direct Physical Casting (SEDPC)” method. The direct observation by high-resolution scanning microscopy (HR-SEM) shows the formation of an ordered mesoporous structure in a very confined area. The cyclic voltammogram of the mesoporous Pt reveals a typical feature of Pt surface. The surface morphology and ordering of the mesostructure strongly depend on the electrodeposition conditions (constant-current and constant-potential depositions). The roughness factors are greatly enhanced as the charge densities in the constant-current deposition are increased. These findings are important for the morphological design of mesoporous metals in a micrometer scale.
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Fabrication of a Pt film with a well-defined hierarchical pore system via “Solvent-Evaporation-mediated direct physical casting”
Elsevier, 2006Co-Authors: Yusuke Yamauchi, Kazuyuki KurodaAbstract:We fabricated a well-ordered Pt thin film with a bimodal pore system by combining the modified liquid crystal templating method (Solvent-Evaporation-mediated direct physical casting, SEDPC) with colloidal crystal templating. The direct observation of the film by high-resolution scanning microscopy (HR-SEM) showed the formation of a hierarchical porous structure. The resulting Pt film possesses macropores (ca. 460 nm), interconnected windows (ca. 100 nm), and mesopores (ca. 3–4 nm). Macropore wall consists of small nanoparticles of ca. 3 nm in size. These nanoparticles are interconnected to create mesoporosity. The cyclic voltammogram of the resulting Pt film in sulfuric acid revealed a typical feature which can identify the clean Pt surface. Keywords: Mesoporous metal, Lyotropic liquid crystal, Colloidal crystal templating, Platinum, Hierarchical structure, Electrode materia
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Fabrication of mesoporous Pt inside micrometer channels via "Solvent-Evaporation-mediated direct physical casting"
Electrochemistry Communications, 2005Co-Authors: Yusuke Yamauchi, Hiroki Kitoh, Toshiyuki Momma, Tetsuya Osaka, Kazuyuki KurodaAbstract:We have proposed a novel convenient pathway via Solvent-Evaporation-mediated direct physical casting (SEDPC) for the fabrication of mesoporous metals in a micrometer scale. We have presented the successful deposition of highly ordered mesoporous Pt into micrometer channels prepared by lithography. The direct observation by a high-resolution scanning microscope (HR-SEM) showed the formation of highly ordered 2D-hexagonal (p6mm) mesoporous metals onto such substrates. The cyclic voltammogram of the mesoporous Pt in sulfuric acid revealed a typical feature which can identify the clean Pt surface. Moreover, mesoporous Pt exhibits an effective reduction of dissolved dioxygen molecules. It is proved that mesoporous Pt deposited in a very confined area via the SEDPC method possesses electrocatalytic performance owing to Pt.
Rong Liu - One of the best experts on this subject based on the ideXlab platform.
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preparation of uniform sized pla microcapsules by combining shirasu porous glass membrane emulsification technique and multiple emulsion Solvent Evaporation method
Journal of Controlled Release, 2005Co-Authors: Rong Liu, Fantao MengAbstract:Relatively Uniform-sized biodegradable poly(lactide) (PLA) microcapsules were successfully prepared by combining a Shirasu Porous Glass (SPG) membrane emulsification technique and multiple emulsion-Solvent Evaporation method. An aqueous phase containing lysozyme was used as the internal water phase (w1), and PLA and Arlacel 83 were dissolved in a mixture Solvent of dichloromethane (DCM) and toluene which was used as the oil phase (o). These two solutions were emulsified by a homogenizer to form a w1/o primary emulsion. The primary emulsion was permeated through the uniform pores (5.25 microm) of an SPG membrane into the external water phase by the pressure of nitrogen gas to form the uniform w1/o/w2 droplets. Then, the solid polymer microcapsules were obtained by simply evaporating the Solvent. It is necessary to avoid the phase separation of primary emulsion during the SPG membrane emulsification. It was found that when the density difference of the internal water phase and oil phase was reduced to nearly zero and Arlacel 83 was used as the oil emulsifier, the phase separation was not observed within 24 h. The w1/o/w2 emulsion with uniform diameter was obtained only when Arlaecl 83 concentration was limited below 2.5 wt.% based on oil phase. The drug encapsulation efficiency was found to be related to several factors including PLA molecular weight, additive type and its concentration in the internal water phase, the emulsifier type and concentration in the oil phase, the NaCl concentration and the pH value in the external water phase. Comparing with the stirring method, it was found that the size was more uniform and the drug encapsulation efficiency was much higher when the microcapsules were prepared by SPG membrane emulsification technique and the highest drug encapsulation efficiency of 92.20% was obtained. This is the first study to prepare PLA microcapsules by combining an SPG membrane emulsification technique and multiple emulsion-Solvent Evaporation method.
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preparation of uniform sized pla microcapsules by combining shirasu porous glass membrane emulsification technique and multiple emulsion Solvent Evaporation method
Journal of Controlled Release, 2005Co-Authors: Rong Liu, Fantao MengAbstract:Relatively Uniform-sized biodegradable poly(lactide) (PLA) microcapsules were successfully prepared by combining a Shirasu Porous Glass (SPG) membrane emulsification technique and multiple emulsion-Solvent Evaporation method. An aqueous phase containing lysozyme was used as the internal water phase (w(1)), and PLA and Arlacel 83 were dissolved in a mixture Solvent of dichloromethane (DCM) and toluene which was used as the oil phase (o). These two solutions were emulsified by a homogenizer to form a w(1)/o primary emulsion. The primary emulsion was permeated through the uniform pores (5.25 mu m) of an SPG membrane into the external water phase by the pressure of nitrogen gas to form the uniform w(1)/o/w(2) droplets. Then, the solid polymer microcapsules were obtained by simply evaporating the Solvent. It is necessary to avoid the phase separation of primary emulsion during the SPG membrane emulsification. It was found that when the density difference of the internal water phase and oil phase was reduced to nearly zero and Arlacel 83 was used as the oil emulsifier, the phase separation was not observed within 24 h. The w(1)/o/w(2) emulsion with uniform diameter was obtained only when Arlaecl 83 concentration was limited below 2.5 wt.% based on oil phase. The drug encapsulation efficiency was found to be related to several factors including PLA molecular weight, additive type and its concentration in the internal water phase, the emulsifier type and concentration in the oil phase, the NaCl concentration and the pH value in the external water phase. Comparing with the stirring method, it was found that the size was more uniform and the drug encapsulation efficiency was much higher when the microcapsules were prepared by SPG membrane emulsification technique and the highest drug encapsulation efficiency of 92.20% was obtained. This is the first study to prepare PLA microcapsules by combining an SPG membrane emulsification technique and multiple emulsion-Solvent Evaporation method. (c) 2004 Elsevier B.V. All rights reserved.
Kazuyuki Kuroda - One of the best experts on this subject based on the ideXlab platform.
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fabrication of a pt film with a well defined hierarchical pore system via Solvent Evaporation mediated direct physical casting
Electrochemistry Communications, 2006Co-Authors: Yusuke Yamauchi, Kazuyuki KurodaAbstract:Abstract We fabricated a well-ordered Pt thin film with a bimodal pore system by combining the modified liquid crystal templating method (Solvent-Evaporation-mediated direct physical casting, SEDPC) with colloidal crystal templating. The direct observation of the film by high-resolution scanning microscopy (HR-SEM) showed the formation of a hierarchical porous structure. The resulting Pt film possesses macropores (ca. 460 nm), interconnected windows (ca. 100 nm), and mesopores (ca. 3–4 nm). Macropore wall consists of small nanoparticles of ca. 3 nm in size. These nanoparticles are interconnected to create mesoporosity. The cyclic voltammogram of the resulting Pt film in sulfuric acid revealed a typical feature which can identify the clean Pt surface.
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development of microfabrication process of mesoporous pt via Solvent Evaporation mediated direct physical casting selective deposition into sloped microchannels
Science and Technology of Advanced Materials, 2006Co-Authors: Yusuke Yamauchi, Hiroki Kitoh, Toshiyuki Momma, Tetsuya Osaka, Kazuyuki KurodaAbstract:AbstractWe have developed an excellent process for selective deposition of mesoporous Pt through tailored microfabrication steps via the “Solvent-Evaporation-mediated Direct Physical Casting (SEDPC)” method. The direct observation by high-resolution scanning microscopy (HR-SEM) shows the formation of an ordered mesoporous structure in a very confined area. The cyclic voltammogram of the mesoporous Pt reveals a typical feature of Pt surface. The surface morphology and ordering of the mesostructure strongly depend on the electrodeposition conditions (constant-current and constant-potential depositions). The roughness factors are greatly enhanced as the charge densities in the constant-current deposition are increased. These findings are important for the morphological design of mesoporous metals in a micrometer scale.
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Fabrication of a Pt film with a well-defined hierarchical pore system via “Solvent-Evaporation-mediated direct physical casting”
Elsevier, 2006Co-Authors: Yusuke Yamauchi, Kazuyuki KurodaAbstract:We fabricated a well-ordered Pt thin film with a bimodal pore system by combining the modified liquid crystal templating method (Solvent-Evaporation-mediated direct physical casting, SEDPC) with colloidal crystal templating. The direct observation of the film by high-resolution scanning microscopy (HR-SEM) showed the formation of a hierarchical porous structure. The resulting Pt film possesses macropores (ca. 460 nm), interconnected windows (ca. 100 nm), and mesopores (ca. 3–4 nm). Macropore wall consists of small nanoparticles of ca. 3 nm in size. These nanoparticles are interconnected to create mesoporosity. The cyclic voltammogram of the resulting Pt film in sulfuric acid revealed a typical feature which can identify the clean Pt surface. Keywords: Mesoporous metal, Lyotropic liquid crystal, Colloidal crystal templating, Platinum, Hierarchical structure, Electrode materia
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Fabrication of mesoporous Pt inside micrometer channels via "Solvent-Evaporation-mediated direct physical casting"
Electrochemistry Communications, 2005Co-Authors: Yusuke Yamauchi, Hiroki Kitoh, Toshiyuki Momma, Tetsuya Osaka, Kazuyuki KurodaAbstract:We have proposed a novel convenient pathway via Solvent-Evaporation-mediated direct physical casting (SEDPC) for the fabrication of mesoporous metals in a micrometer scale. We have presented the successful deposition of highly ordered mesoporous Pt into micrometer channels prepared by lithography. The direct observation by a high-resolution scanning microscope (HR-SEM) showed the formation of highly ordered 2D-hexagonal (p6mm) mesoporous metals onto such substrates. The cyclic voltammogram of the mesoporous Pt in sulfuric acid revealed a typical feature which can identify the clean Pt surface. Moreover, mesoporous Pt exhibits an effective reduction of dissolved dioxygen molecules. It is proved that mesoporous Pt deposited in a very confined area via the SEDPC method possesses electrocatalytic performance owing to Pt.
Jeffrey S Moore - One of the best experts on this subject based on the ideXlab platform.
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low ceiling temperature polymer microcapsules with hydrophobic payloads via rapid emulsion Solvent Evaporation
ACS Applied Materials & Interfaces, 2017Co-Authors: Shijia Tang, Mostafa Yourdkhani, Catherine Possanza M Casey, Nancy R Sottos, Scott R White, Jeffrey S MooreAbstract:We report a microencapsulation procedure based on rapid Solvent Evaporation to prepare microcapsules with hydrophobic core materials and low-ceiling-temperature polymer shell wall of cyclic poly(phthalaldehyde) (cPPA). We use and compare microfluidic and bulk emulsions. In both methods, rapid Solvent Evaporation following emulsification resulted in kinetically trapped core–shell microcapsules, whereas slow Evaporation resulted in acorn morphology. Through the systematic variation of encapsulation parameters, we found that polymer-to-core weight ratios higher than 1 and polymer concentrations higher than 4.5 wt % in the oil phase were required to obtain a core–shell structure. This microencapsulation procedure enabled the fabrication of microcapsules with high core loading, controlled size, morphology, and stability. This procedure is versatile, allowing for the encapsulation of other hydrophobic core materials, i.e., mineral oil and organotin catalyst, or using an alternative low-ceiling-temperature polym...
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Low-Ceiling-Temperature Polymer Microcapsules with Hydrophobic Payloads via Rapid Emulsion-Solvent Evaporation
2017Co-Authors: Shijia Tang, Mostafa Yourdkhani, Catherine Possanza M Casey, Nancy R Sottos, Scott R White, Jeffrey S MooreAbstract:We report a microencapsulation procedure based on rapid Solvent Evaporation to prepare microcapsules with hydrophobic core materials and low-ceiling-temperature polymer shell wall of cyclic poly(phthalaldehyde) (cPPA). We use and compare microfluidic and bulk emulsions. In both methods, rapid Solvent Evaporation following emulsification resulted in kinetically trapped core–shell microcapsules, whereas slow Evaporation resulted in acorn morphology. Through the systematic variation of encapsulation parameters, we found that polymer-to-core weight ratios higher than 1 and polymer concentrations higher than 4.5 wt % in the oil phase were required to obtain a core–shell structure. This microencapsulation procedure enabled the fabrication of microcapsules with high core loading, controlled size, morphology, and stability. This procedure is versatile, allowing for the encapsulation of other hydrophobic core materials, i.e., mineral oil and organotin catalyst, or using an alternative low-ceiling-temperature polymer shell wall, poly(vinyl tert-butyl carbonate sulfone)