Microsphere-Based Coatings for Radioactive Cooling Under Direct Sunlight

Abstract

The present prevention provides a surface coating for cooling a surface by light scattering comprising a plurality of successive layers, each of the layers may be comprised of a plurality of spheres arranged to form a structure comprised of packed spheres. Each layer may have a different arrangement of packed spheres to create to a different light scattering property in each of the layers. The coating of the structures may also be formed by randomly packed spheres and the spheres may have a uniform diameter.

1 - 39 . (cancelled) 
     
     
         40 . A film for cooling a surface of a substrate by light scattering comprising:
 a plurality of layers in said film, each of said layers comprised of a plurality of spheres arranged to form a structure comprised of randomly packed spheres; and   said spheres have a uniform diameter.   
     
     
         41 . The film of  claim 40  wherein said uniform diameter of said spheres is greater than 0.4 microns. 
     
     
         42 . The film of  claim 40  wherein said uniform diameter of said spheres is less than 3 microns. 
     
     
         43 . The film of  claim 40  wherein said uniform diameter of said spheres is 0.4-3 microns. 
     
     
         44 . The film of  claim 40  wherein said uniform diameter of said spheres is 1-3 microns. 
     
     
         45 . The film of  claim 44  wherein said spheres are hollow. 
     
     
         46 . The film of  claim 46  wherein said hollow spheres have a shell thickness of 1-100 nanometers. 
     
     
         47 . The film of  claim 46  wherein said hollow spheres have a shell thickness greater than 1 nanometer. 
     
     
         48 . The film of  claim 40  wherein said film has an average light emissivity of greater than 80% in a range of 8-13 microns. 
     
     
         49 . The film of  claim 46  wherein said film also has an average light emissivity of greater than 80% in a range of 18-30 microns. 
     
     
         50 . The film of  claim 40  wherein each of said layers has a different degree of randomness. 
     
     
         51 . A film for cooling a surface of a substrate by light scattering comprising:
 a plurality of spheres arranged to form a structure comprised of randomly packed spheres; and   said spheres have a uniform diameter.   
     
     
         52 . The film of  claim 51  wherein said uniform diameter of said spheres is greater than 0.4 microns. 
     
     
         53 . The film of  claim 51  wherein said uniform diameter of said spheres is less than 3 microns. 
     
     
         54 . The film of  claim 51  wherein said uniform diameter of said spheres is 0.4-3 microns. 
     
     
         55 . The film of  claim 51  wherein said uniform diameter of said spheres is 1-3 microns. 
     
     
         56 . The film of  claim 54  wherein said spheres are hollow. 
     
     
         57 . The film of  claim 56  wherein said hollow spheres have a shell thickness of 1-100 nanometers. 
     
     
         58 . The film of  claim 56  wherein said hollow spheres have a shell thickness greater than 1 nanometer. 
     
     
         59 . The film of  claim 51  wherein said film has an average light emissivity of greater than 80% in a range of 8-13 microns. 
     
     
         60 . The film of  claim 51  wherein said film also has an average light emissivity of greater than 80% in a range of 18-30 microns. 
     
     
         61 . A film for cooling a surface of a substrate by light scattering comprising:
 a plurality of successive layers in said film;   each of said layers comprised of a plurality randomly packed spheres;   each structure of each layer has a different arrangement of said randomly packed spheres to create to a different light scattering property in each of said layers;   said layers are comprised of lateral periodic structures and non-periodic structures; and   said periodic layers are ordered structures and said non-periodic structures are random structures.   
     
     
         62 . The film of  claim 61  wherein each of said layers is made of a monolayer of microspheres with a predetermined degree of randomness. 
     
     
         63 . The film of  claim 61  wherein each of said layers has a sphere filling fraction of less than 55%. 
     
     
         64 . The film of  claim 61  wherein each of said layers has a sphere filling fraction between 20-45% and said spheres have a diameter between 0.4 and 1 micron. 
     
     
         65 . The film of  claim 61  wherein each of said layers has spheres joined into fibrillar networks and said fibrillar networks of each layer have different periodicities and orientations.