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自發性孢子顆粒於平面流體與乳化之應用 Naturally Occurring Spore Particles at Planar Fluid Interfaces and in Emulsions By B. P. Binks et al. 國立成功大學 奈米科技暨微系統工程研究所. 博一 連剛逸 Q28961012 碩一 李珍儀 Q26964014. Outline. Motivation Introduction of Emulsion Principle Emulsion Emulsifying Agents Types of Emulsions
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自發性孢子顆粒於平面流體與乳化之應用 Naturally Occurring Spore Particles at Planar Fluid Interfaces and in Emulsions By B. P. Binks et al. 國立成功大學 奈米科技暨微系統工程研究所 博一 連剛逸 Q28961012 碩一 李珍儀 Q26964014
Outline • Motivation • Introduction of Emulsion Principle • Emulsion • Emulsifying Agents • Types of Emulsions • Naturally occurring spore particles at planar fluid interfaces and in emulsions • Materials • Emulsions Stabilized by Spore Particles • Spontaneous Adsorption of Spore Particles • Applications and Consumer Products • Conclusions • Future work
Introduction of Emulsification Principle • Emulsions are disperse multi-phase systems of two or more insoluble liquids. • Emulsions consist of at least one continuous (outer) phase (e.g. water) and one isolated (dispersed or inner) phase (e.g. oil).
Water Water Oil Oil Introduction of Emulsion Principle Mechanical agitation Ultrasonic vibration Heat Water (Continuous phase) Oil (Dispersed phase) Oil-in-water (o/w)-emulsion
Introduction of Emulsion Principle • Emulsifying Agents (Surfactant) Hydrophilic Lipophilic ＋ Water － Oil Surfactant molecule Surfactant
Water Oil Introduction of Emulsion Principle • Types of Emulsion • Hydrophilic Lipophilic Balance (HLB) Oil-in-water (o/w)-emulsion Water-in-oil (w/o)-emulsion Water-in-oil-in-water (w/o/w)-emulsion oil-in-Water-in-oil (o/w/o)-emulsion
Materials SEM image of dry Lycopodium clavatum (石松) spore particles. Notice their rough surface structure and the presence of a Y-shaped marking. Scale bar = 25 mm.
Materials Photograph of vessels (d=2.5 cm) initially containing equal volumes of water and an IPM dispersion of spore particles (2 wt %/vol) after hand shaking (left) and homogenization via Ultra Turrax (right), 3 months after formation. The middle-layer in both cases is an o/w emulsion.
Emulsions Stabilized by Spore Particles Photograph of vessels initially containing equalvolumes of water and an IPM dispersion of spore particles after Ultra Turrax homogenization 3 months after formation. The concentrations of spore particles in the total liquid mixture from left to right are the following: 0.25, 1.0, 2.5, and 5.0 wt%/vol. The emulsion formed at all concentrations is o/w. (b) Variation of the average oil drop diameter and range of sizes as a function of spore particle concentration in emulsions of IPM (R=0.5) and water. Optical microscopy images of IPM-in-water emulsion drops (R=0.5) stabilized by spore particles prepared using an Ultra Turrax mixer. The concentrations of particles in the system are (a) 1 and (b) 3 wt %/vol. Scale bar = 200 mm on both
Spontaneous Adsorption of Spore Particles Photographs showing the formation of spore particle coated water drops (d=0.5 cm) in octane. (a) A bare water drop is formed under oil above a layer of sediment spore particles; (b) the drop is allowed to touch the particle bed and particles spontaneously attach to the lower surface; (c) after repeating step b twice, most of the drop surface contains adsorbed particles; (d) several water drops are formed in this way and finally detached from the pipette Optical microscopy image in situ of the external surface of a large (0.3 cm) water drop in octane containing spontaneously adsorbed spore particles, approximately halfway down the drop. Scale bar = 50 mm.
Conclusion • Naturally occurring spore particles of Lycopodium clavatum act as efficient stabilizers of oil and water, preferring to stabilize o/w emulsions with oils of a range of polarities • An increase in the particle concentration leads to a decrease in the average drop size. • Drops of millimeter size are completely stable to coalescence even though the coverage of drop interfaces by particles is no more than 20%.
(Double emulsions) Low calorie food products Encapsulation of medicines Applications and Consumer Products Emulsions • Droplets Size • Droplets Uniformity • Emulsion Stability Foods Cosmetics Paints & Dye Drug delivery
Drug or Bio material Functional Shell Future application • Nanocapsule for drug delivery Thousands of nanometers Biological cells have diameters in the range of thousands of nanometers. Nanometers Ten shoulder-to-shoulder hydrogen atoms span 1nanometer. DNA molecules are about 2.5 nanometers wide. Less than a nanometer Individual atoms are up to a few tenths of a nanometer in diameter.
