Patent application number | Description | Published |
20100105112 | FLUOROCARBON EMULSION STABILIZING SURFACTANTS - Surfactants (e.g., fluorosurfactants) for stabilizing aqueous or hydrocarbon droplets in a fluorophilic continuous phase are presented. In some embodiments, fluorosurfactants include a fluorophilic tail soluble in a fluorophilic (e.g., fluorocarbon) continuous phase, and a headgroup soluble in either an aqueous phase or a lipophilic (e.g., hydrocarbon) phase. The combination of a fluorophilic tail and a headgroup may be chosen so as to create a surfactant with a suitable geometry for forming stabilized reverse emulsion droplets having a disperse aqueous or lipophilic phase in a continuous, fluorophilic phase. In some embodiments, the headgroup is preferably non-ionic and can prevent or limit the adsorption of molecules at the interface between the surfactant and the discontinuous phase. This configuration can allow the droplet to serve, for example, as a reaction site for certain chemical and/or biological reactions. In another embodiment, aqueous droplets are stabilized in a fluorocarbon phase at least in part by the electrostatic attraction of two oppositely charged or polar components, one of which is at least partially soluble in the dispersed phase, the other at least partially soluble in the continuous phase. One component may provide collodial stability of the emulsion, and the other may prevent the adsorption of biomolecules at the interface between a component and the discontinous phase. Advantageously, surfactants and surfactant combinations of the invention may provide sufficient stabilization against coalescence of droplets, without interfering with processes that can be carried out inside the droplets. | 04-29-2010 |
20100239824 | Metal Oxide Coating On Surfaces - The present invention provides a method for coating metal oxide on a PDMS surface. The method includes preparing a mixture that contains a sol-gel precursor, reacting the mixture to form a preconverted sol-gel precursor, where the preconverted sol-gel precursor does not diffuse into PDMS and is not in the form of a gel, forming a reactive PDMS surface, applying the preconverted sol-gel precursor onto the reactive PDMS surface, binding the preconverted sol-gel precursor to the re-active PDMS surface, and converting the bound preconverted sol-gel precursor to a metal oxide to form a metal oxide coating on the PDMS surface. The present invention also provides a PDMS microfluidic device where one or more channels of the microfluidic device is provided with a metal oxide coating covalently bound only on the surface of the one or more channels. | 09-23-2010 |
Patent application number | Description | Published |
20110229545 | MELT EMULSIFICATION - The present invention generally relates to colloidal systems, which may include colloidal particles and/or other types of particles. One aspect of the invention is generally directed to a system comprising fluidic droplets that can be at least partially solidified, e.g., to form colloidal particles. In some embodiments, particles comprising an at least partially solid outer phase encapsulating an inner phase are formed. The inner phase may be any phase, e.g., a solid, a liquid, or a gas. In some cases, solidifying at least a portion of the outer phase of the droplets to form particles may increase the stability of the particles and/or the colloidal system containing the particles. In one set of embodiments, melting or liquefying the outer phase of the particles (for example, by heating the particle to a temperature above a threshold temperature) can allow release of an agent contained within the inner phase, and/or allow the inner phase to coalesce with a phase external to the particles. The melting temperature of the outer phase can be controlled in some embodiments such that the outer phase will melt above a predetermined temperature. In some embodiments, the particles may be formed to be essentially free of an auxiliary stabilizing agent. In some embodiments, an agent may be encapsulated within a particle with relatively high efficiency. Other aspects of the invention are generally directed to methods of making and using such colloidal systems, e.g., containing such particles, kits involving such colloidal systems, or the like. | 09-22-2011 |
20120167410 | SPRAY DRYING TECHNIQUES - The present invention generally relates to microfluidics, and to spray drying and other drying techniques. In some aspects, an article containing one or more channels or microfluidic channels is used to mix one or more fluids prior to spray drying. The mixing may occur immediately before the fluids are expelled through a nozzle or other opening into a drying region of the spray dryer. In one set of embodiments, for example, a first fluid is exposed to a second fluid, then the fluids are exposed to air or other gases before being expelled through a nozzle. In certain instances, the first fluid may contain a dissolved species that may precipitate upon exposure to the second fluid; such precipitation may occur immediately before expulsion through a nozzle or other opening, thereby resulting in controlled precipitation as part of the spray drying process. | 07-05-2012 |
20120199226 | MULTIPLE EMULSIONS CREATED USING JUNCTIONS - The present invention generally relates to emulsions, and more particularly, to multiple emulsions. In one aspect, multiple emulsions are formed using a plurality of channels, such as microfluidic channels, that meet at a common intersection. The multiple emulsions may be created at a single common intersection in some embodiments, unlike other prior art systems where multiple channel intersections are required to create multiple emulsions. For instance, in one set of embodiments, three, four, or more microfluidic channels may intersect at a common intersection, with two or three serving as inlets and one serving as the outlet. In some embodiments, a first fluidic channel may be relatively hydrophobic, while a second fluidic channel is relatively hydrophilic. The third channel, if present, may be relatively hydrophilic or hydrophobic, depending on the application. The outlet channel may be hydrophobic, hydrophilic, or may comprise at least one portion that is relatively hydrophilic and at least one portion that is relatively hydrophilic. By controlling the flow of fluids through the hydrophilic and hydrophobic portions of the channels, multiple emulsions may be created proximate the common intersection, due to interactions between the fluids entering the common intersection. In other embodiments, different patterns of hydrophilic or hydrophobic channels may be used. Other aspects of the invention are generally directed to methods of making and using such systems, kits involving such systems, emulsions created using such systems, or the like. | 08-09-2012 |
20130046030 | CONTROL OF EMULSIONS, INCLUDING MULTIPLE EMULSIONS - The present invention generally relates to emulsions, and more particularly, to double and other multiple emulsions. Certain aspects of the present invention are generally directed to the creation of double emulsions and other multiple emulsions at a common junction of microfluidic channels. In some cases, the microfluidic channels at the common junction may have substantially the same hydrophobicity. In one set of embodiments, a device may include a common junction of six or more channels, where a first fluid flows through one channel, a second fluid flows through two channels, and a third or carrying fluid flows through two more channels, such that a double emulsion of a first droplet of the first fluid, contained in a second droplet of the second fluid, contained by the carrying fluid, flows away from the common junction through a sixth channel. | 02-21-2013 |
20130064862 | SYSTEMS AND METHODS FOR SHELL ENCAPSULATION - Certain aspects of the invention are generally directed to particles comprising a shell and an interior at least partially contained by the shell. In some embodiments, the particles may be treated to enhance the containment of the interior, for example to reduce transport of an agent into or out of the interior. Such particles may exhibit increased ability to encapsulate agents and/or increased storage life (e.g., due to reduced leakage). For instance, in certain embodiments, any defects, such as cracks, pores, etc. within the shell may be sealed or otherwise treated to reduce transport therethrough. In some embodiments, for instance, a first reactant in the interior of a particle may come into contact with a second reactant outside of the particle to form a solid, or other suitable product. The shell may also be treated to cause release of an agent contained within the interior, in certain aspects. | 03-14-2013 |
20140150916 | SURFACES, INCLUDING MICROFLUIDIC CHANNELS, WITH CONTROLLED WETTING PROPERTIES - The present invention generally relates to coating materials, including photoactive coating materials. In some aspects of the invention, a sol-gel is provided that can be formed as a coating on a microfluidic channel. One or more portions of the sol-gel can be reacted to alter its hydrophobicity, in some cases. For instance, in one set of embodiments, a portion of the sol-gel may be exposed to light, such as ultraviolet light, which can be used to induce a chemical reaction in the sol-gel that alters its hydrophobicity. In one set of embodiments, the sol-gel can include a photoinitiator, that upon exposure to light, produces radicals. Optionally, the photoinitiator may be conjugated to a silane or other material within the sol-gel. The radicals so produced may be used to cause a polymerization reaction to occur on the surface of the sol-gel, thus altering the hydrophobicity of the surface. In some cases, various portions may be reacted or left unreacted, e.g., by controlling exposure to light (for instance, using a mask). Such treated surfaces within a microfluidic channel may be useful in a wide variety of applications, for instance, in the creation of emulsions such as multiple emulsions. | 06-05-2014 |
20140284001 | SYSTEMS AND METHODS FOR SPRAY DRYING IN MICROFLUIDIC AND OTHER SYSTEMS - The present invention generally relates to microfluidics, and to spray drying and other drying techniques. By at least partially drying fluids within a microfluidic channel, instead of or in addition to conventional spray drying techniques, better control of the drying process can be achieved in certain aspects of the invention. In addition, various embodiments of the invention are generally directed to systems and methods for drying fluids contained within a channel such as a microfluidic channel. For example, a fluid may be partially or completely dried within a microfluidic channel, prior to being sprayed into a collection region. In some embodiments, gases such as air may be directed into a channel containing a fluid, which may facilitate drying of the fluid. In some cases, the fluid may be accelerated due to the introduction of gases into the channel, and in certain embodiments, droplets of fluid may be disrupted to form smaller droplets as a result. In certain cases, the fluids may also be dried to form supersaturated droplets. | 09-25-2014 |