# US 2008/0187752 A1 · Process for preparing microrods using liquid-liquid dispersion > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0187752 A1 - Document ID: US20080187752A1 - Status: Published application - Kind: A1 - Application number: 12/019,867 - Filed: 2008-01-25 - Published: 2008-08-07 - Earliest claimed: 2004-06-16 - Assignees: North Carolina State University - Inventors: Orlin Dimitrov Velev; Rossitza Gueorguieva Alargova - Web page: https://patentgrep.com/patent/US20080187752A1 ## CPC - D01D 5/40: by applying a shearing force to a dispersion or solution of filament formable polymers, e.g. by stirring - A61K 9/5094: {Microcapsules containing magnetic carrier material, e.g. ferrite for drug targeting} - C08J 3/11: from solid polymers - C08J 3/12: Powdering or granulating - C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins - Y10T 428/2933: Coated or with bond, impregnation or core - Y10T 428/2973: Particular cross section - D01D: MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS - A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D) - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The invention provides a method for forming polymer microrods, the method including the steps of providing a polymer solution comprising a polymer dissolved in a first solvent; providing a dispersion medium comprising a second solvent, wherein the first solvent and the second solvent are miscible or partially soluble in each other, and wherein the polymer is insoluble in the second solvent; adding the polymer solution to the dispersion medium to form a dispersed phase of polymer solution droplets within the dispersion medium; and introducing a shear stress to the dispersion medium and dispersed polymer solution droplets for a time and at a shear rate sufficient to elongate the polymer solution droplets to form microrods and solidify the microrods by attrition of the polymer solvent into the dispersion medium. ## Claims ### Claim 1 A plurality of polymer microrods having an average aspect ratio of at least about 5, an average length of about 10 to about 100 μm, and an average diameter of about 0.1 to about 10 μm. ### Claim 2 (depends on 1) The plurality of polymer microrods of claim 1, wherein the average aspect ratio is at least about 20. ### Claim 3 (depends on 1) The plurality of polymer microrods of claim 1, wherein the average length is about 10 to about 50 μm. ### Claim 4 (depends on 1) The plurality of polymer microrods of claim 1, wherein the average diameter is about 0.5 to about 3 μm. ### Claim 5 (depends on 1) The plurality of polymer microrods of claim 1, wherein the microrods comprise a polymer selected from the group consisting of polyolefin, polyether, polyamide, polyamideimide, polyarylate, polybenzimidazole, polyester, polyurethane, polyimide, polyhydrazide, phenolic resins, polysilane, polysiloxane, polycarbodiimide, polyimine, azo polymers, polysulfide, polysulfone, copolymers thereof, and mixtures thereof. ### Claim 6 (depends on 1) The plurality of polymer microrods of claim 1, wherein the microrods comprise a polymer selected from the group consisting of polyethylene, polypropylene, poly(vinyl chloride), polystyrene, polytetrafluoroethylene, poly(α-methylstyrene), poly(acrylic acid), poly(isobutylene), poly(acrylonitrile), poly(methacrylic acid), poly(methyl methacrylate), poly(1-pentene), poly(1,3-butadiene), poly(vinyl acetate), poly(2-vinyl pyridine), 1,4-polyisoprene, 3,4-polychloroprene, poly(ethylene oxide), polyformaldehyde, polyacetaldehyde, poly(3-propionate), poly(10-decanoate), poly(ethylene terephthalate), polycaprolactam, poly(11-undecanoamide), poly(hexamethylene sebacamide), poly(m-phenylene terephthalate), and poly(tetramethylene-m-benzenesulfonamide). ### Claim 7 (depends on 1) The plurality of polymer microrods of claim 1, wherein the microrods comprise an epoxy resin. ### Claim 8 (depends on 1) The plurality of polymer microrods of claim 1, wherein the microrods comprise a naturally-occurring polymer. ### Claim 9 (depends on 1) The plurality of polymer microrods of claim 1, wherein the microrods comprises a particulate material imbedded therein. ### Claim 10 (depends on 9) The plurality of polymer microrods of claim 9, wherein the particulate material comprises silica or magnetic particles. ### Claim 11 (depends on 1) The plurality of polymer microrods of claim 1, wherein the polymer microrods can be rotated or aligned by application of an external electric or magnetic field. ### Claim 12 (depends on 1) The plurality of polymer microrods of claim 1, wherein the polymer microrods are anisotropic. ### Claim 13 (depends on 1) The plurality of polymer microrods of claim 1, wherein the polymer microrods are crosslinked. ### Claim 14 (depends on 1) A material selected from the group consisting of liquid crystal materials, nonwoven textiles, paper materials, porous fibrillar materials, pads, linings, sponges, filters, food products, paints, pharmaceutical compositions, cosmetics, bath products, latex foams, polyurethane foams, and fibrillar matrices for cell attachment, the material comprising a plurality of polymer microrods according to claim 1. ### Claim 15 (depends on 14) The material of claim 14, wherein the material is a food product selected from the group consisting of ice cream, mayonnaise, salad dressings, and whipped cream. ### Claim 16 (depends on 14) The material of claim 14, wherein the material is a pharmaceutical composition comprising the polymer microrods in the form of colloidosome microcapsules.