Nanocellulose-based anti-fogging composition

Abstract

An anti-fogging composition is described herein. The composition includes a nanocellulose comprising cellulose nanofibrils, cellulose nanocrystals, or a combination thereof, and water. A method of preparing an anti-fogging coating includes applying the anti-fogging composition to at least a portion of a surface of a substrate to form a coating. An article including a coating formed from the anti-fogging composition is also disclosed. Coatings prepared from the anti-fogging compositions are water proof, and offer a cost-effective alternative to other anti-fogging coatings.

1 . An anti-fogging composition, comprising
 a nanocellulose comprising cellulose nanofibrils, cellulose nanocrystals, or a combination thereof; and   water.   
     
     
         2 . The anti-fogging composition of  claim 1 , further comprising a surfactant, a water-soluble polymer, a plurality of nanoparticles, or a combination thereof. 
     
     
         3 . The anti-fogging composition of  claim 2 , wherein the surfactant comprises a polyoxyalkylene, an organosiloxane, a C 3-20  perfluoroalkyl group, a C 4-24  fatty acid or an alkali metal salt thereof, or a combination thereof. 
     
     
         4 . The anti-fogging composition of  claim 2 , wherein the surfactant is an alkali metal salt of coconut oil. 
     
     
         5 . The anti-fogging composition of  claim 2 , wherein the water-soluble polymer comprises polyvinylpyrrolidone, polyvinyl alcohol, polyacrylic acid, methyl cellulose, hydroxypropyl methylcellulose, xanthan gum, pectin, guar gum, carrageenan, chitosan, gelatin, gum arabic, or a combination thereof. 
     
     
         6 . The anti-fogging composition of  claim 2 , wherein the water-soluble polymer comprises xanthan gum. 
     
     
         7 . The anti-fogging composition of  claim 2 , wherein the nanoparticles comprise silica nanoparticles, zinc oxide nanoparticles, titanium dioxide nanoparticles, or a combination thereof. 
     
     
         8 . The anti-fogging composition of  claim 1 , comprising 0.1 to 10 weight percent nanocellulose. 
     
     
         9 . The anti-fogging composition of  claim 1 , comprising 0.1 to 1.5 weight percent nanocellulose comprising cellulose nanofibrils. 
     
     
         10 . The anti-fogging composition of  claim 1 , comprising 0.1 to 8 weight percent nanocellulose comprising cellulose nanocrystals. 
     
     
         11 . The anti-fogging composition of  claim 1 , comprising
 0.1 to 1.5 weight percent nanocellulose; and   98.5 to 99.9 weight percent water.   
     
     
         12 . The anti-fogging composition of  claim 2 , comprising
 0.1 to 1.5 weight percent of the nanocellulose;   0.01 to 1 weight percent of the surfactant;   0.01 to 1 weight percent of the water-soluble polymer; and   96.5 to 99.88 weight percent water;   wherein weight percent is based on the total weight of the composition.   
     
     
         13 . The anti-fogging composition of  claim 2 , comprising
 0.1 to 0.5 weight percent nanocellulose;   0.25 to 1 weight percent of the surfactant;   0.01 to 0.5 weight percent of the water-soluble polymer; and   98 to 99.55 weight percent water;   wherein weight percent is based on the total weight of the composition.   
     
     
         14 . The antifogging composition of  claim 13 , wherein
 the nanocellulose comprises cellulose nanofibrils;   the surfactant is an alkali metal salt of coconut oil; and   the water-soluble polymer is xanthan gum.   
     
     
         15 . An article comprising a coating formed from the anti-fogging composition of  claim 1 . 
     
     
         16 . The article of  claim 15 , wherein the article is at least partially transparent. 
     
     
         17 . The article of  claim 15 , wherein the article is a mirror, a window, eyeglasses, sunglasses, goggles, safety glasses, a helmet, a visor, a windshield, a lens, a display screen, a freezer door, or a greenhouse roof. 
     
     
         18 . A method of preparing an anti-fogging coating, the method comprising
 applying the anti-fogging composition of  claim 1  to at least a portion of a surface of a substrate to form a coating.   
     
     
         19 . The method of  claim 18 , wherein applying the composition comprises solution coating, spray coating, wiping using a saturated sponge or cloth, or a combination thereof. 
     
     
         20 . The method of  claim 19 , wherein the surface is a glass surface, a ceramic surface, a metal surface, or a polymeric surface.