Spectrally selective coatings and associated methods for minimizing the effects of lightning strikes

Abstract

A coating composition for reducing structural damage to a substrate resulting from interaction between the substrate and lightening plasma is disclosed. The coating composition includes a binder having a plurality of pigment particles that have a size distribution of a first portion of pigment particles that are relatively large compared to ultraviolet (UV) wavelengths from lightning plasma thereby backscattering UV energy, and a second portion of pigment particles that are relatively small compared to infrared (IR) wavelengths thereby forward scattering IR energy.

What is claimed is: 
     
         1 . A coating composition for reducing structural damage to a substrate resulting from interaction between the substrate and lightening plasma comprising:
 a binder having a plurality of pigment particles;   wherein the plurality of pigment particles has a size distribution comprising a first portion of pigment particles that are relatively large compared to ultraviolet (UV) wavelengths from lightning plasma thereby backscattering UV energy, and a second portion of pigment particles that are relatively small compared to infrared (IR) wavelengths thereby forward scattering IR energy.   
     
     
         2 . The coating composition of  claim 1  wherein the first portion of pigment particles backscatter wavelengths from about 10 nm to 200 nm. 
     
     
         3 . The coating composition of  claim 1  wherein the first portion of pigment particles backscatter wavelengths below 500 nm. 
     
     
         4 . The coating composition of  claim 1  wherein the first portion of pigment particles and the second portion of pigment particles include substantially spherical pigment particles or substantially flat-shaped pigment particles. 
     
     
         5 . The coating composition of  claim 1  wherein the pigment particles of the plurality include a quarter wave stack including silicon dioxide defining a first sub-layer thickness and titanium dioxide defining a second sub-layer thickness. 
     
     
         6 . The coating composition of  claim 1  wherein the pigment particles of the plurality include a quarter wave stack including a first material defining a first sub-layer thickness and a second material defining a second sub-layer thickness, wherein the first material has a different index of refraction as a function of the wavelength than the second material. 
     
     
         7 . The coating composition of  claim 6  wherein the quarter wave stack is received over a layer of aluminum. 
     
     
         8 . The coating composition of  claim 7  wherein the layer of aluminum is at most about 1 μm thick and the total thickness of the spectrally selective coating, including the layer of aluminum, is less than about 1.4 μm. 
     
     
         9 . The coating composition of  claim 1  wherein the binder comprises one or more of a material that is transparent or semitransparent to visible light, and a material sufficiently transparent in the vacuum ultraviolet range. 
     
     
         10 . A composite for reducing structural damage thereto resulting from lightening plasma comprising:
 a substrate coated with a coating composition comprising:   a binder having a plurality of pigment particles;   wherein the plurality of pigment particles has a size distribution comprising a first portion of pigment particles that are relatively large compared to ultraviolet (UV) wavelengths from lightning plasma thereby backscattering UV energy, and a second portion of pigment particles that are relatively small compared to infrared (IR) wavelengths thereby forward scattering IR energy.   
     
     
         11 . The composite of  claim 10  wherein the substrate is not inherently reflective of UV energy. 
     
     
         12 . The composite of  claim 10  wherein the substrate include carbon fibers. 
     
     
         13 . The composite of  claim 10  wherein the substrate includes a carbon nanotube reinforced polymer material. 
     
     
         14 . The composite of  claim 10  wherein the plurality of pigment particles includes niobium particles, silicon dioxide particles, titanium dioxide particles, or combinations thereof. 
     
     
         15 . The composite of  claim 10  wherein the binder includes polyurethane. 
     
     
         16 . The composite of  claim 10  wherein the first portion of pigment particles and the second portion of pigment particles include substantially spherical pigment particles or substantially flat-shaped pigment particles. 
     
     
         17 . The composite of  claim 10  wherein the first portion of pigment particles and the second portion of pigment particles include substantially spherical pigment particles. 
     
     
         18 . The composite of  claim 10  wherein the first portion of pigment particles and the second portion of pigment particles include substantially flat-shaped pigment particles. 
     
     
         19 . The composite of  claim 10  wherein the pigment particles of the plurality include a quarter wave stack including silicon dioxide defining a first sub-layer thickness and titanium dioxide defining a second sub-layer thickness. 
     
     
         20 . The composite of  claim 10  wherein the pigment particles of the plurality include a quarter wave stack including a first material defining a first sub-layer thickness and a second material defining a second sub-layer thickness, wherein the first material has a different index of refraction as a function of the wavelength than the second material. 
     
     
         21 . The coating composition of  claim 20  wherein the quarter wave stack is received over a layer of aluminum.