520 results about "Shear thinning" patented technology

A physical blend of inverse thermal gelling and shear-thinning, thixotropic polymers that has a lower gelation temperature than the thermal gelling polymer alone is provided. The blend results in an injectable hydrogel that does not flow freely at room temperature, but is injectable due to its shear-thinning properties. The thermal-gelling properties of the polymer promote a more mechanically stable gel at body temperature than at room temperature. The polymer matrix gel has inherent therapeutic benefit and can also be used as a drug delivery vehicle for localized release of therapeutic agents.

A structured liquid detergent composition in the form of a liquid matrix made up of an external structuring system of a bacterial cellulose network; water; and surfactant system including an anionic surfactant; a nonionic surfactant; a cationic surfactant; an ampholytic surfactant; a zwitterionic surfactant; or mixtures thereof, wherein said liquid matrix has a yield stress of from about 0.003 Pa to about 5.0 Pa at about 25° C. and provides suitable particle suspension capabilities and shear thinning characteristics.

Injectable depot compositions are provided that include a polymer matrix having a plurality of bioerodible, biocompatible polymers wherein wherein each polymer of the plurality of polymers has a specified weight average molecular weight; and the polymer matrix has a broad molecular weight distribution of the plurality of polymers; a solvent having a miscibility in water of less than or equal to 7 wt. % at 25° C., in an amount effective to plasticize the polymer and form a gel therewith; and a beneficial agent. The compositions are have substantially improved the shear thinning behavior and reduced injection force, rendering the compositions readily implanted beneath a patient's body surface by injection.

The present invention provided for a novel process of forming silk fibroin gels, and controlling the rate of β-sheet formation and resulting hydrogelation kinetics, by vortex treatment of silk fibroin solution. In addition, the vortex treatment of the present invention provides a silk fibroin gel that may be reversibly shear-thinned, enabling the use of these approach for precise control of silk self-assembly, both spatially and temporally. Active agents, including biological materials, viable cells or therapeutic agents, can be encapsulated in the hydrogels formed from the processes, and be used as delivery vehicles. Hence, the present invention provide for methods for silk fibroin gelation that are useful for biotechnological applications such as encapsulation and delivery of active agents, cells, and bioactive molecules.

An aqueous, low pH structured surfactant composition, contains, based on 100 parts by weight of the composition, from about 3 parts by weight to about 40 parts by weight of one or more anionic surfactants selected from anionic phosphate ester surfactants, anionic sulfonate surfactants, and anionic carboxylate surfactants, wherein the composition exhibits a pH of less than about 5, exhibits shear-thinning viscosity, and is capable of suspending water insoluble or partially water soluble components.

A polychromic ink composition depending on viewing angle comprises 0.5 to 40% by weight of cholesteric liquid crystal polymer particles whose maximum particle diameter is 1 to 200 mum, 1.0 to 30.0% by weight of binder resins, 0.05 to 20% by weight of pigments with a deep-colored coloring matter whose average particle diameter is 0.01 to 0.5 mum, 0.01 to 5.0% by weight of a shear-thinning property imparting agent, and water with respect to the total amount of the ink composition.

A method for the thickening of mineral oil products, wherein the thickened mineral oil product exhibits shear-thinning so as to be applicable to a surface by non-pressurized spray mechanisms. The thickening agent added to the petroleum distillate comprises a thixotropic thickener chosen from the group consisting of mixtures comprising a triblock copolymer and a hydrocarbon oil, and N-Lauroyl glutamic acid di-n-butylamide.

The invention relates to compositions that prevent expansion of a fire, suppress existing fire, as well as methods of preparing and using such compositions. The composition is comprised of water, pseudo-plastic high yield suspending agent and starch. Compositions may contain additional functional agents, such as rheological, wetting, foaming, coloring, chelating, antimicrobial and stabilizing agents. In the description of the present invention, all composition modifications are referred to as compositions. The composition, an augmentation of water, exhibits the characteristics of a sag resistant aqueous gel in the tank, but has shear thinning capacity, allowing the composition to be pumped or sprayed as easily as water. At the point of impact, when the sprayed composition is again at rest, it instantly reverts to a sag resistant aqueous gel. The composition also forms an intumescent, surface char layer upon contacting a fire. Foaming of the augmented composition on impact can be incorporated, which is advantageous for fighting petroleum fires.

A sunscreen composition, either impregnating a wipe substrate or comprising a sunscreen spray, wherein the composition comprises an oil phase dispersed stably as emulsion droplets in a water phase that contains i) a booster for the sun protection factor (SPF), comprising a combination of water-dispersible particulate materials, one of which is smectite clay, and a water-soluble or water-dispersible phenolic polymer; and ii) a water-soluble or water-dispersible polymer having a weak acid group, a weight average molecular weight of 1,000-100,000 Dalton, and an anionic charge density of no less than 4 milliequivalent per gram of the polymer; the said sunscreen composition meeting the following specifications: i) the in-vivo sun protection factor (SPF) is ≧1.8 times the weight percent of the sunscreen active(s) contained therein, based on the weight of the sunscreen composition; and ii) the shear thinning index of the composition is greater by 5% or higher with the weak acid polymer contained therein than without the polymer, the shear thinning index being defined as the ratio of viscosities of the sunscreen composition at 0.5 rpm and 20 rpm, measured on a Brookfield RVT viscometer at 25 ° C., using spindle 7, after cooling the composition to room temperature and storing it at that temperature for about 24 hours.

An apparatus and method are disclosed wherein at least one parameter associated with a core-annular flow (CAF) in a pipe is measured by sensing unsteady pressures associated with undulations formed at the interface of a core region and an annular region in the CAF at different axial locations along the pipe. The at least one parameter, which may include a flow velocity of the CAF, Mach number associated with the CAF, and a volumetric flow rate of the CAF, is determined using sensed unsteady pressures. The CAF may be developed from a shear thinning fluid, such as bitumen froth or from a wood pulp fiber suspension. Alternatively, the CAF may be developed from a lubricating fluid, such as water, and a fluid to be transported, such as oil, where the fluid to be transported forms the core region and the lubricating fluid forms the annular region.

In an ink jet printing apparatus for high speed/high quality printing, an ink jet ink having a high concentration of solids the range of about 20-70 wt. %, and exhibiting shear-thinning characteristics.

Catheter injectable depot compositions are provided that include a bioerodible, biocompatible polymer, a solvent having miscibility in water of less than or equal to 7 wt. % at 25° C., in an amount effective to plasticize the polymer and form a gel therewith, a thixotropic agent, and a beneficial agent. The solvent comprises an aromatic alcohol, an ester of an aromatic acid, an aromatic ketone, or mixtures thereof. The compositions have substantially improved shear thinning behavior and reduced injection force, rendering the compositions readily implanted beneath a patient's body surface by injection.

A device, system, and method for direct delivery of a therapeutic to a target site that utilizes the non-Newtonian characteristics of shear thinning and shear thickening to allow easy passage of a therapeutic through a delivery lumen yet facilitate retention of the therapeutic in the target site. The device, system, and method includes increasing the shear rate or shear stress of a non-Newtonian fluid having therapeutic properties thereby increasing or decreasing the viscosity of the non-Newtonian fluid.

An in-reactor polymer blend comprises (a) a propylene-containing first polymer; and (b) an ethylene-containing second polymer such that the polymer blend comprises between about 50 wt % and about 80 wt % units derived from ethylene and between about 50 wt % and about 20 wt % units derived from propylene. The blend is substantially free of dienes and the content of ethylene in the second polymer in the form of ethylene-ethylene-ethylene triads is at least 40%. The second polymer contains at least 0.1 branch having 8 or more carbon atoms per 10,000 carbons. In addition, the blend has a strain hardening index of at least 1.8, a shear thinning slope in the plot of log(dynamic viscosity) versus log(frequency) of less than −0.2 and exhibits at least two peaks when subjected to Differential Scanning Calorimetry (first melt) corresponding to a first melting point of at least 150° C. and a second melting point of at least 40° C. such that the difference between the first and second melting temperatures is at least 20° C.

A method of treating a subterranean formation penetrated by a wellbore includes preparing a treatment fluid with shear thinning, non-monotonic rheological properties, injecting the treatment fluid into the subterranean formation, and inducing shear rate softening phase transition in the treatment fluid. The non-monotonic rheology properties can be such that in the relationship between shear stress (σ) versus strain rate ({dot over (γ)}), where {dot over (γ)}₁<{dot over (γ)}₂<{dot over (γ)}₃<{dot over (γ)}₄, the shear stress values are σ₁<σ₂σ₃≦σ₄, and σ₃<σ₂ The method can heterogeneously deposit proppant or solid acid in a fracture. A system to fracture a subterranean formation includes the fracturing fluid, a wellbore to inject the fracturing fluid to propagate a fracture in the formation, and a rate controller to inject the fracturing fluid into the subterranean formation at a minimum volumetric rate to provide a shear stress at an inlet to the fracture that exceeds σ₂. The method and system can achieve heterogeneous particle placement with either proppant or solid acid.

Disclosed is a method of increasing the low shear rate viscosity and the shear thinning index of aqueous fluids containing a divalent cation salt, a crosslinked amylopectin starch which functions as both a viscosifier/suspending agent and as a fluid loss control additive, and a bridging agent, the fluids resulting from the method, and the use of the fluids in drilling a well, wherein the bridging agent is a sized particulate magnesium carbonate or a mixture of sized magnesium carbonate and sized calcium carbonate. The median (D.sub.50) particle size of the magnesium carbonate is from about 2 .mu.m to about 10 .mu.m. The weight ratio of calcium carbonate to magnesium carbonate is from about 70/30 to about 0/100.

Highly branched compositions including: (i) from about 96 wt % to about 99.9 wt % metallocene catalyzed ethylene propylene diene derived units; and (ii) from about 0.1 wt % to about 4 wt % multifunctional monomer derived units, wherein the highly branched composition has: (a) a Mooney viscosity ML (1+4) at 125° C. of about 30 to 100 MU, (b) a Mooney relaxation area MLRA of about 100 to about 1000, (c) a branching index, g′(vis) of less than about 0.9, (d) a phase angle, δ, of less than about 55 degrees at a complex modulus of 10 kPa, measured at 190° C., and (e) a degree of shear thinning greater than about 0.95, measured at 190° C., are disclosed herein. Homogeneous blends including this composition are also described. Processes to make the highly branched composition and the homogeneous blend are also described herein.

This invention relates to a blend composition comprising: 1) a linear ethylene containing polymer, such as a LLDPE, a HDPE or the like; and at least 1 weight percent of an in-reactor polymer blend comprising: (a) a first ethylene containing polymer having a density of greater than 0.90 g/cm³ and a M_w of more than 20,000 g/mol; and (b) a second ethylene containing polymer having a density of less than 0.90 g/cm³, wherein the polymer blend has a T_m of at least 90° C. (DSC second melt), a density of less than 0.92 g/cm³, and the densities of the first and second polymers differ by at least 1%. Alternately the in-reactor polymer blend comprises: (a) a first ethylene polymer comprising 90 wt % to 100 wt % ethylene and from 0 wt % to less than 10 wt % comonomer, said first ethylene polymer component having density of greater than 0.920 g/cm³, an M_w of 20,000 g/mol or more; and (b) a second ethylene polymer comprising from 70 wt % to 90 wt % ethylene and 30 wt % to 10 wt % comonomer, said second ethylene polymer having a density of 0.910 g/cm³ or less, wherein the in-reactor polymer blend has one or more of the following characteristics: (a) at least 78 wt % ethylene; (b) a T_m of at least 100° C. over a density ranging from 0.84 to 0.92 g/cm³; (c) a elongation at break of 300% or more; (d) a strain hardening ratio M300/M100 of at least 1.2; (e) a ratio of complex viscosity at 0.01 rad/s to the complex viscosity at 100 rad/s of at least 30; and (f) a shear thinning index of less than −0.2.