19278 results about "Colloid" patented technology

A coating composition is disclosed which comprises an aqueous polymeric matrix, a hydrophilic polymer, a colloidal metal oxide and a crosslinker. The coating composition when applied on medical devices is hydrophilic, shows improved lubricity, abrasion resistance and substrate adhesion on metallic or plastic substrates. The coating also shows improved water sheeting thus providing the coated substrates with anti-fog properties. The coating absorbs aqueous dye or stain solutions making the substrate suitable for printing.

Solid free form fabrication techniques can be utilized indirectly to manufacture substrates, dies, models, near-net shapes, shells, and wax-ups that are then used in the manufacture of dental articles. Digital light processing is the most preferred indirect method for the production of substrates. After the substrates are produced, various coating or deposition techniques such as gel casting, slip casting, slurry casting, pressure infiltration, dipping, colloidal spray deposition or electrophoretic deposition are used to manufacture the dental article.

This invention discloses a cost-effective process for separating contaminants and a wide-range of fouling material from surface water, ground water and from industrial effluents. Having undergone effective pre-treatment, the water can be purified further by using high-surface area spirally wound micro-filtration (MF), ultra-filtration (UF), nano-filtration (NF) or reverse osmosis (RO) membranes. High-quality potable water free from pathogen and other contaminants is thus produced at low-cost from the pre-treated surface water and ground-water. Conversely, pre-treated industrial effluents are further purified at a relatively low-cost using NF or RO membranes, thus producing water suitable for recycle or surface discharge. The process of this invention uses cationic inorganic and/or polymeric flocculants to coagulate and flocculate the water-borne colloidal matter (e.g. clays, iron hydroxides, naturally occurring matter (NOM's), etc.), followed by filtration using a multi-media filter, charge neutralization and reversal and final filtration using a 5-micron cartridge filter. These pre-treatment steps provides a good quality water having a low Silt Density Index and a significant negative zeta potential, thereby ensuring against irreversible chemical fouling of the spirally-wound membranes.

A prosthetic device for implantation into a mammalian body comprised of a non-absorbable biocompatible flexible material shell or sac filled with various biocompatible gel filler materials. The gel filler materials are comprised of biocompatible glucomannan obtained from konjac hydrocolloid flour and other biocompatible hydrocolloids, producing a natural look and feel for the prosthetic implants, especially reconstructive prostheses such as breast implants.

Mucosal surface-coat-forming film dosage units containing a water-soluble hydrocolloid, an effective dose of an active agent and a mucosal adhesion enhancer; wherein the active agent is encapsulated within a polymer which is chemically or physically distinct from the hydocolloid; wherein the mucosal adhesion enhancer is a starch graft copolymer; wherein the film exhibits a dry tack value of less than 3.5 g, a wet tack of greater than 35 g, a gelation temperature that is greater than 70° C. for a 2% polymer solution, a dry film thickness of less than 20 mil, a water content of 0.5 to 10%, a tensile strength greater than 1500 psi, a modulus in the range of 35,000 to 300,000 psi, a % elongation of less than 20%, a tear probagation resistance of 0.001 to 1 N, and a dissolution time in the range of 1 to 600 seconds upon application to an oral mucosal surface.

A method of synthesizing colloidal nanocrystals is disclosed using metal oxides or metal salts as a precursor. The metal oxides or metal salts are combined with a ligand and then heated in combination with a coordinating solvent. Upon heating, the metal oxides or salts are converted to stable soluble metal complexes. The metal complexes are formed by cationic species combining with the ligands and/or with the coordinating solvent. Finally, an elemental chalcogenic precursor, for example, Se, Te, or S, is introduced into the soluble metal complex to complete the formation of the nanocrystals at a controllable rate. High-quality CdSe, CdTe, and CdS nanocrystals are produced when CdO is used as the cadmium precursor. With the present method, the size, size distribution, and shape (dots or rods) of the resulting nanocrystals can be controlled during growth. For example, the resulting nanocrystals are nearly monodisperse without any size separation. Further, the method represents a major step towards a green chemistry approach for synthesizing high-quality semiconductor nanocrystals.

The present invention provides a photocatalyst-carrying structure which has a structure, wherein an adhesive layer is provided in between a photocatalyst layer and a substrate, the adhesive layer is composed of silicon-modified resin, polysiloxane-containing resin or colloidal silica-containing resin, and for forming the photocatalyst layer a composition comprising a metal oxide gel or a metal hydroxide gel and a photocatalyst is used. Further, the present invention also provides a photocatalyst coating agent for producing a photocatalyst-carrying structure which contains silicon compound, at least one metal oxide sol or metal hydroxide sol, and at least one photocatalyst powder or sol.

A membrane filter apparatus includes a membrane unit 50 composed of an array of membrane elements 51 disposed within a treatment tank 31. A skirt element 71 is disposed at a bottom portion of the membrane unit and an aerator 61 is disposed under the skirt. A partition is also disposed at the bottom of the membrane unit forming compartments within the skirt element. The gas bubbles discharged from the aerator increase their rising force upon entry into gaps between the membranes. Because of the arrangement of the partition within the skirt element the flow rate of bubbles along the opposite side edge portions of the membrane unit can be increased having the advantage of cleaning the entire surface of each membrane, thereby preventing clogging by sludge, SS, colloid, etc. within the gaps between the membranes. Therefore, filtration can be maintained over a longer period of time and the power required for filtration can be reduced, as well as, the frequency of manual periodic cleaning, chemical cleaning, etc.

Compositions are provided comprising a lipophilic active compound, e.g., a human or veterinary drug or a nutraceutical, interwoven with a polymeric matrix formed by two or more polymers, wherein one of the polymers is an amphiphilic polymer and the other polymer is either an amphiphilic polymer with a different hydrophobic-hydrophilic balance or a hydrophilic polymer, and the active lipophilic compound has modified physicochemical properties. The composition forms colloidal nanodispersion upon contact with aqueous media.

In one aspect, the present invention is directed to a glucose sensing device for implantation within subcutaneous tissue of an animal body. In one embodiment, the glucose sensing device includes a first chamber containing first magnetic particles and a hydrocolloid solution (for example, ConA-dextran hydrocolloid) wherein the first magnetic particles are dispersed in the hydrocolloid solution. In operation, glucose within the animal may enter and exit the first chamber and the hydrocolloid solution changes in response to the presence or concentration of glucose within the first chamber. The sensing device also includes a reference chamber containing second magnetic particles and a reference solution wherein the second magnetic particles are dispersed in the reference solution. The reference solution (for example, oil or alcohol compounds) includes a known or fixed viscosity. The reference solution may also be a hydrocolloid solution (for example, ConA-dextran hydrocolloid). The first and/or second magnetic particles may include amine-terminated particles, at least one rare earth element (for example, neodymium or samarium), and/or a ferromagnetic material.

The present invention relates to antimicrobial compositions, methods for the production of these compositions, and use of these compositions with medical devices, such as catheters, and implants. The compositions of the present invention advantageously provide varying release kinetics for the active ions in the compositions due to the different water solubilities of the ions, allowing antimicrobial release profiles to be tailored for a given application and providing for sustained antimicrobial activity over time. More particularly, the invention relates to polymer compositions containing colloids comprised of salts of one or more oligodynamic metal, such as silver. The process of the invention includes mixing a solution of one or more oligodynamic metal salts with a polymer solution or dispersion and precipitating a colloid of the salts by addition of other salts to the solution which react with some or all of the first metal salts. The compositions can be incorporated into articles or can be employed as a coating on articles such as medical devices. Coatings may be on all or part of a surface.

This invention relates to novel forms of clarified hydrocolloids including gels, films, foams, capsules and sponges. The invention also pertains to novel processes for producing the various physical forms of the clarified hydrocolloids. The invention also includes clarified hydrocolloid composites; borated cis 1,2-diol containing hydrocolloids; and clarified hydrocolloids of low viscosity.

A film-forming hydrocolloid composition comprising kappa carrageenan, iota carrageenan, a bulking agent, plasticizer and water is described. The ratio of bulking agent to total carrageenan is from about 1:1 to 20:1. Kappa carrageenan is present in an amount of less than or equal to 50% by weight of total carrageenan present. To form the composition, all dry materials are mixed and added to a heated mixture of all liquid materials. The final mixture is heated until a composition free of particulate materials is formed. The formed composition can be cast or extruded into ribbons, films, sheets, tubes or the like, for encapsulating wet or dry materials including medicinal dosage forms, nutritional supplements, cosmetics, bath oils and gels, and paint balls.

A filtration system is provided with hollow membrane filter elements operable to remove solids, particulate and colloidal matter from a process fluid. Acoustic, vibration and ultrasonic energy may be used to clean exterior portions of the hollow membrane filter elements to allow substantially continuous filtration of process fluids. The filtration system may be satisfactorily used with process fluids having a relatively high concentrations of solids, particulate and colloidal matter.

Compositions are provided comprising aqueous dispersions of polythienothiophenes and colloid-forming polymeric acids. Films from invention compositions are useful as hole injection layers in organic electronic devices, including electroluminescent devices, such as, for example, organic light emitting diodes (OLED) displays, as hole extraction layers in organic optoelectronic devices, such as organic photovoltaic devices, and in combination with metal nanowires or carbon nanotubes in applications such as drain, source, or gate electrodes in thin film field effect transistors.

An aqueous cutting fluid which can reduce the impact on working environment and the global environment, and can achieve both preventing precipitates from becoming a hard cake and keeping high dispersibility for abrasive grains is provided. Such an aqueous cutting fluid is obtained by a method comprising dispersing abrasive grains (G) in an aqueous composition comprising a dispersion medium (M) containing a hydrophilic alcohol compound such as ethylene glycol, a lipophilic alcohol compound such as propylene glycol and water, and silica colloid particles dispersed stably in the medium. The dispersion medium (M) is odorless and not flammable. The abrasive grains (G) may settle out after a time, but they do not closely contact with one another, and therefore the resulting precipitates do not become a hard cake, which allows the re-dispersion and reuse of precipitated grains. The instant aqueous cutting fluid is inherently low viscous, and the reduction of viscosity owing to the contamination of water and the increase of viscosity owing to contamination of shavings are both moderate. As a result, the cutting fluid has a long life. And articles which have been cut using the cutting fluid can be washed with water. Further, as the dispersion medium (M) is a biodegradable low molecular weight organic compound, a waste liquid from a process using the cutting fluid can be disposed with an activated sludge.

The present invention provides new compositions containing colloidal nanocrystals with high photoluminescence quantum yields, new synthetic methods for the preparation of highly luminescent colloidal nanocrystals, as well as methods to control the photoluminescent properties of colloidal nanocrystals. The new synthetic methods disclosed herein allow photoemission brightness (quantum yield) to be correlated with certain adjustable nanocrystal growth parameters associated with a given synthetic scheme.

A process for producing a fine silver particle colloidal dispersion which can simply form conductive silver layers and antimicrobial coatings by screen printing or the like. The process is characterized by having a reaction step of allowing an aqueous silver nitrate solution to react with a mixed solution of an aqueous iron(II) sulfate solution and an aqueous sodium citrate solution to form an agglomerate of fine silver particles, a filtration step of filtering the resultant agglomerate of fine silver particles to obtain a cake of the agglomerate of fine silver particles, a dispersion step of adding pure water to the cake to obtain a first fine silver particle colloidal dispersion of a water system in which dispersion the fine silver particles have been dispersed in the pure water, and a concentration and washing step of concentrating and washing the first fine silver particle colloidal dispersion of a water system.

An edible film that rapidly disintegrates when placed in the mouth to release an active agent, the film consisting of a hydrocolloid film-forming material and microparticles containing active agent

The invention relates to thermosensitive polymers which contain magnetic and/or metallic colloids and whose physical structure can be altered through magnetic induction or through the supply of energy. The invention also relates to processes for the production of such thermosensitive polymers, and the use of such polymers for diagnostic and therapeutic purposes.