# US 2021/0275433 A1 · Janus particles and their use for surfactant-free cleansing and emulsion stabilization > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0275433 A1 - Document ID: US20210275433A1 - Status: Published application - Kind: A1 - Application number: 16/338,894 - Filed: 2017-10-02 - Published: 2021-09-09 - Earliest claimed: 2016-10-03 - Assignees: The Trustees of Princeton University - Applicants: The Trustees of Princeton University - Inventors: Rodney D. PRIESTLEY; Robert K. PRUD'HOMME; Sunny NIU - Web page: https://patentgrep.com/patent/US20210275433A1 ## CPC - B82B 3/00: Manufacture or treatment of nanostructures by manipulation of individual atoms or molecules, or limited collections of atoms or molecules as discrete units - A61K 8/044: {Suspensions} - A61K 8/062: {Oil-in-water emulsions} - A61K 8/068: {Microemulsions} - A61K 8/85: Polyesters - A61K 8/90: Block copolymers (A61K8/89 takes precedence) - A61Q 19/10: Washing or bathing preparations - B01J 13/0021: {containing a solid organic phase} - B32B 5/00: Layered products characterised by the non- homogeneity or physical structure {, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts} - C09K 23/00: Use of substances as emulsifying, wetting, dispersing, or foam-producing agents - A61K 2800/33: Free of surfactant - A61K 2800/412: Microsized, i.e. having sizes between 0.1 and 100 microns - A61K 2800/654: The particulate/core comprising macromolecular material - B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites - C11D 2111/10: Objects to be cleaned - B82B: NANOSTRUCTURES FORMED BY MANIPULATION OF INDIVIDUAL ATOMS, MOLECULES, OR LIMITED COLLECTIONS OF ATOMS OR MOLECULES AS DISCRETE UNITS; MANUFACTURE OR TREATMENT THEREOF - 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) - A61Q: SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C11D: DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL ## Abstract Janus particles, including biodegradable, biocompatible, anisotropic, amphiphilic Janus nanocolloids, and their use in stabilizing emulsions and cleansing are described. ## Claims ### Claim 1 An emulsion comprising an asymmetric Janus (two-faced) nanoparticle comprising a hydrophilic surface as a hydrophilic face and a hydrophobic surface as a hydrophobic face; a hydrophilic liquid; a hydrophobic liquid; and an interface between the hydrophilic liquid and the hydrophobic liquid, wherein the asymmetric Janus nanoparticle is located at the interface. ### Claim 2 (depends on 1) The emulsion of claim 1, wherein the asymmetric Janus nanoparticle consists of at least one organic polymer. ### Claim 3 (depends on 1) The emulsion of claim 1, wherein the asymmetric Janus nanoparticle comprises a block copolymer comprising a more hydrophilic block and a more hydrophobic block. ### Claim 4 (depends on 3) The emulsion of claim 3, wherein the asymmetric Janus nanoparticle further comprises a homopolymer. ### Claim 5 (depends on 4) The emulsion of claim 4, wherein the block copolymer and the homopolymer are biodegradable and/or biocompatible. ### Claim 6 (depends on 1) The emulsion of claim 1, wherein the hydrophilic surface comprises a high glass-transition temperature (Tg) polymer and wherein the hydrophobic surface comprises a low glass-transition temperature (Tg) polymer. ### Claim 7 (depends on 6) The emulsion of claim 6, wherein the high glass-transition temperature polymer is selected from the group consisting of hydrophilic-functionalized polystyrene (PS), polylactic acid (PLA), and hydrophilic-functionalized polylactic acid (PLA) and wherein the low glass-transition temperature polymer is selected from the group consisting of polyisoprene (PI) and polybutadiene (PB). ### Claim 8 (depends on 1) The emulsion of claim 1, wherein the hydrophilic surface comprises polymethacrylic acid (PMAA), polyvinylpyridine (PVP), polyethylene oxide (PEO), and/or a hydrophilic functionalized polymer selected from the group consisting of polystyrene (PS), polymethylmethacrylate (PMMA), polylactic acid (PLA), and polyvinylcyclohexane (PVCH), and combinations. ### Claim 9 (depends on 1) The emulsion of claim 1, wherein the hydrophobic surface comprises a polymer selected from the group consisting of polyisoprene (PI), polybutadiene (PB), poly(ethylene-vinylacetate) (PEVA), polycaprolactone (PCL), and combinations. ### Claim 10 (depends on 1) The emulsion of claim 1, wherein the hydrophilic surface comprises a polymer selected from the group consisting of hydroxy-terminated polystyrene (PS), carboxyl-terminated polystyrene (PS), amine-terminated polystyrene (PS), hydroxy-terminated polybutadiene (PB), carboxyl-terminated polybutadiene (PB), amine-terminated polybutadiene (PB), hydroxy-terminated polyisoprene (PI), carboxyl-terminated polyisoprene (PI), amine-terminated polyisoprene (PI), and combinations. ### Claim 11 (depends on 1) The emulsion of claim 1, wherein the hydrophobic surface comprises a polymer selected from the group consisting of polystyrene (PS), polybutadiene (PB), polyisoprene (PI), and combinations. ### Claim 12 (depends on 1) The emulsion of claim 1 wherein the hydrophilic surface comprises polylactic acid (PLA) and wherein the hydrophobic surface comprises polystyrene (PS), polyisoprene (PI), and/or polybutadiene (PB). ### Claim 13 (depends on 1) The emulsion of claim 1, wherein the asymmetric Janus nanoparticle comprises polylactic acid (PLA) polymer and polyethylene oxide-block-polycaprolactone (PEO-b-PCL) copolymer. ### Claim 14 (depends on 1) The emulsion of claim 1, wherein the hydrophilic surface comprises polyethylene oxide-block-polycaprolactone (PEO-b-PCL) copolymer and wherein the hydrophobic surface comprises polylactic acid (PLA) polymer. ### Claim 15 (depends on 1) The emulsion of claim 1, wherein the asymmetric Janus nanoparticle comprises polyethylene oxide-block-polycaprolactone (PEO-b-PCL) copolymer. ### Claim 16 (depends on 1) The emulsion of claim 1, wherein the asymmetric Janus nanoparticle comprises polylactic acid (PLA) polymer and polycaprolactone (PCL) copolymer. ### Claim 17 (depends on 13) The emulsion of claim 13, wherein the polylactic acid (PLA) polymer has a molecular weight in the range of from 10 kDa to 20 kDa. ### Claim 18 (depends on 14) The emulsion of claim 14, wherein the polyethylene oxide (PEO) component of the polyethylene oxide-block-polycaprolactone (PEO-b-PCL) copolymer has a molecular weight in the range of from 3 kDa to 10 kDa, and wherein the polycaprolactone (PCL) component of the polyethylene oxide-block-polycaprolactone (PEO-b-PCL) copolymer has a molecular weight in the range of from 10 kDa to 20 kDa. ### Claim 19 (depends on 1) The emulsion of claim 1, wherein the asymmetric Janus nanoparticle has a diameter in the range of from 400 nm to 800 nm. ### Claim 20 (depends on 1) The emulsion of claim 1, wherein the asymmetric Janus nanocolloid comprises a first hydrophobic polymer, a second polymer, and an amphiphilic block copolymer, wherein the first hydrophobic polymer forms the hydrophobic face, wherein the second polymer forms the hydrophilic face, wherein the second polymer has amine or carboxylic functionality at its terminal end, and wherein the amphiphilic block copolymer comprises a hydrophobic block formed of the same monomer units of which the first hydrophobic polymer is formed. ### Claim 21 (depends on 20) The emulsion of claim 20, wherein polyethylene glycol polymers are coupled through 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) molecules to the amine functionality of the second polymer. ### Claim 22 A method of cleansing skin or another surface, comprising: applying a colloid suspension comprising an asymmetric Janus nanoparticle and water (or another liquid) to the skin or other surface; and rinsing the colloid suspension from the skin or other surface with water (or another liquid), wherein the asymmetric Janus nanoparticle comprises a high glass transition temperature (Tg) polymer and a low glass transition temperature (Tg) polymer, wherein the high glass transition temperature polymer has hydrophilic groups at a hydrophilic face of the Janus nanoparticle, wherein the low glass transition polymer has oleophilic groups at an oleophilic face of the Janus nanoparticle. ### Claim 23 (depends on 22) The method of claim 22, wherein the high glass transition temperature polymer is polystyrene (PS) functionalized with hydrophilic groups and wherein the low glass transition temperature polymer is polyisoprene (PI). ### Claim 24 (depends on 22) The method of claim 22, wherein the high glass transition temperature polymer is polylactic acid (PLA) and wherein the low glass transition temperature polymer is polycaprolactone (PCL). ### Claim 25 A geometrical Janus micelle, comprising: an aggregate of a plurality of Janus particles, wherein each Janus particle has a surface having a hydrophilic face and an oleophilic face and wherein the oleophilic face of each Janus particle is oriented toward a center of mass of the aggregate. ### Claim 26 (depends on 25) The geometrical Janus micelle of claim 25, wherein the hydrophilic face comprises a high glass transition temperature polymer and wherein the hydrophobic face comprises a low glass transition temperature polymer. ### Claim 27 (canceled) ### Claim 28 (depends on 25) A method of forming the geometrical Janus micelle of claim 25, comprising: forming the plurality of Janus particles in a first flash nanoprecipitation step; suspending the plurality of Janus particles in a process solvent to form a process solution; and continuously mixing the process solution with a nonprocess salt solution in a second flash nanoprecipitation step to form the geometrical Janus micelle, wherein the geometrical Janus micelle comprises the aggregate of the plurality of Janus particles.