# US 10,502,505 B2 · Radiative cooling structures and systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,505 B2 - Document ID: US10502505B2 - Status: Granted - Kind: B2 - Application number: 15/056,680 - Filed: 2016-02-29 - Published: 2017-08-31 - Granted: 2019-12-10 - Earliest claimed: 2016-02-29 - Assignees: The Regents of the Univeristy of Colorado, a body corporate; University of Wyoming - Applicants: The Regents of the University of Colorado, A Body Corporate; University of Wyoming - Inventors: Ronggui Yang; Xiaobo Yin; Gang Tan; Dongliang Zhao; Yaoguang Ma; Yao Zhai - Web page: https://patentgrep.com/patent/US10502505B2 ## CPC - F28F 13/18: by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing - B23P 15/26: heat exchangers {or the like (making heat exchangers by methods covered by other subclasses B21D53/02)} - F28F 21/02: of carbon, e.g. graphite - F28F 21/067: {Details} - F28F 21/089: {Coatings, claddings or bonding layers made from metals or metal alloys (F28F19/06 takes precedence)} - B32B 27/32: comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} - B32B 27/36: comprising polyesters - B32B 2255/10: on synthetic resin layer or on natural or synthetic rubber layer - B32B 2255/205: Metallic coating - B32B 2264/102: Oxide or hydroxide - B32B 2307/416: Reflective - F28F 2245/06: having particular radiating, reflecting or absorbing features, e.g. for improving heat transfer by radiation - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM ## Abstract Polymer-based selective radiative cooling structures are provided which include a selectively emissive layer of a polymer or a polymer matrix composite material. Exemplary selective radiative cooling structures are in the form of a sheet, film or coating. Also provided are methods for removing heat from a body by selective thermal radiation using polymer-based selective radiative cooling structures. ## Claims ### Claim 1 A selective radiative cooling structure, the structure comprising: a selectively emissive layer comprising a polymer and a plurality of dielectric particles dispersed in the polymer, the volume percentage of the dielectric particles in the selectively emissive layer selected from the range of 1% to 25% and the particles characterized by an average size ranging from 3 μm to 30 μm; a reflective layer comprising a metal film or metal substrate, wherein the selectively emissive layer is provided on the reflective layer; wherein the selective radiative cooling structure is characterized by an average emissivity ranging from 0.6 to 1.0 over the wavelength range 7 μm to 13 μm; wherein the selectively emissive layer has a transmissivity of 0.7 to 1 over a solar wavelength range of 0.3 μm to 3 μm; wherein the polymer is selected from the group consisting of polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), a 4-methyl-1-pentene polymer, a 4-methyl-1-pentene copolymer and polyvinyl fluoride; wherein the dielectric particles comprise silicon dioxide (SiO2); and wherein the reflective layer is a silver film characterized by an average thickness from 20 nanometers to 300 nanometers. ### Claim 2 (depends on 1) The selective radiative cooling structure of claim 1, wherein the structure is in the form of a sheet. ### Claim 3 (depends on 1) The selective radiative cooling structure of claim 1, wherein the selective radiative cooling structure provides a radiative heat flux from 50 W/m2 to 150 W/m2 at a working temperature of 15° C. ### Claim 4 (depends on 1) The selective radiative cooling structure of claim 1, wherein the dielectric particles are characterized by an average size ranging from 4 μm to 10 μm. ### Claim 5 (depends on 1) The selective radiative cooling structure of claim 1, wherein the selectively emissive layer is characterized by an average thickness from 10 μm to 3 mm. ### Claim 6 (depends on 1) The selective radiative cooling structure of claim 1, wherein the selective radiative cooling structure further comprises a solar transparent, water-proof or weather resistant protective film that is a solar transparent and weather-resistant polymer. ### Claim 7 (depends on 1) The selective radiative cooling structure of claim 1, wherein a barrier layer or a protective layer is provided between said selectively emissive layer and said reflective layer. ### Claim 8 (depends on 1) The selective radiative cooling structure of claim 1, wherein the particles are characterized by an average size of 8 μm. ### Claim 9 (depends on 1) The selective radiative cooling structure of claim 1, wherein the polymer and dielectric particles are mixed as a uniform blend. ### Claim 10 (depends on 1) The selective radiative cooling structure of claim 1, wherein the selectively emissive layer is characterized by an average thickness from 5 μm to 500 μm. ### Claim 11 (depends on 1) The selective radiative cooling structure of claim 1, wherein the volume percentage of the dielectric particles in the selectively emissive layer selected from the range of 5% to 15%. ### Claim 12 (depends on 1) The selective radiative cooling structure of claim 1, wherein the polymer is selected from the group consisting of polyethylene terephthalate (PET), a 4-methyl-1-pentene polymer, and a 4-methyl-1-pentene copolymer. ### Claim 13 (depends on 1) The selective radiative cooling structure of claim 1, wherein the polymer is selected from the group consisting of a 4-methyl-1-pentene polymer, and a 4-methyl-1-pentene copolymer. ### Claim 14 (depends on 1) The selective radiative cooling structure of claim 1, wherein the polymer is a 4-methyl-1-pentene copolymer copolymer. ### Claim 15 (depends on 1) The selective radiative cooling structure of claim 1, wherein the polymer is a copolymer of poly(4-methyl-1 pentene) with α-olefins selected from the group consisting of 1-pentene, 1-hexene and 1-octene. ### Claim 16 (depends on 15) The selective radiative cooling structure of claim 15, wherein the dielectric particles are silica. ### Claim 17 (depends on 16) The selective radiative cooling structure of claim 16, wherein the selectively emissive layer is characterized by an average thickness from 5 μm to 500 μm. ### Claim 18 (depends on 17) The selective radiative cooling structure of claim 17, wherein the dielectric particles are characterized by an average size ranging from 4 μm to 10 μm. ### Claim 19 (depends on 18) The selective radiative cooling structure of claim 18, wherein the volume percentage of the dielectric particles in the selectively emissive layer selected from the range of 5% to 15%. ### Claim 20 (depends on 19) The selective radiative cooling structure of claim 19, wherein the polymer and dielectric particles are mixed as a uniform blend.