Durable charged particle coatings and materials
View Patent ↗This invention concerns coatings having high surface area materials and at least one metal ion adsorbed onto the high surface area material as well as substrates having the coating and methods of applying the coating. The substrates may be films, woven fabrics or may be nonwoven fabrics. The coatings have good odor and/or gas absorbing capabilities. Nonwoven fabrics include tissues, towels, coform materials, bonded carded webs, spunbond fabrics and so forth. The substrates may be made into storage and packaging material to reduce odor and retard the ripening of fruit. The substrates may be used in personal care products, to produce clothing for military and civilian applications and many other applications.
1. A fibrous substrate comprising:
nanoparticles having a surface area of at least about 50 square meters per gram, wherein the nanoparticles are modified with a metal ion and have a negative zeta potential prior to modification with the metal ion, and wherein the zeta potential of the modified nanoparticles is from about −5 millivolts to about −15 millivolts and is greater than the zeta potential of the nanoparticles prior to modification; and
a binder that durably adheres the modified nanoparticles to the substrate.
2. The substrate of claim 1 , wherein the negative zeta potential is from about −1 millivolt to about −50 millivolts.
3. The substrate of claim 1 , wherein the metal ion is adsorbed onto a surface of the nanoparticles.
4. The substrate of claim 1 , wherein the metal ion forms a coordinate or covalent bond with the nanoparticles.
5. The substrate of claim 1 , wherein the nanoparticles have a surface area of at least about 100 square meters per gram.
6. The substrate of claim 1 , wherein the nanoparticles have a size of less than about 500 nanometers.
7. The substrate of claim 1 , wherein the nanoparticles comprise silica.
8. The substrate of claim 1 , wherein the metal ion includes copper, silver, gold, iron, manganese, or combinations thereof.
9. The substrate of claim 1 , wherein the substrate contains polyolefin fibers.
10. The substrate of claim 1 , wherein the substrate is a spunbond web, meltblown web, or combination thereof.
11. The substrate of claim 1 , wherein the substrate contains cellulosic fibers.
12. The substrate of claim 1 , wherein the modified nanoparticles constitute from about 0.1 to about 10 wt.% of the substrate.
13. The substrate of claim 1 , wherein the binder constitutes from about 0.01 to about 5 wt.% of the substrate.
14. A personal care product comprising the substrate of claim 1 .
15. Protective barrier clothing comprising the substrate of claim 1 .
16. The substrate of claim 1 , wherein the nanoparticles and binder are sequentially applied to the substrate.
17. A fibrous substrate comprising:
first nanoparticles having a surface area of at least about 50 square meters per gram, wherein the first nanoparticles are modified with a metal ion and have a negative zeta potential prior to modification with the metal ion; and
second nanoparticles having a positive zeta potential that durably adhere the modified nanoparticles to the substrate.
18. The substrate of claim 17 , wherein the second nanoparticles have a zeta potential of from about 1 millivolt to about 70 millivolts.
19. The substrate of claim 17 , wherein the first nanoparticles have a zeta potential of from about −1 millivolt to about −50 millivolts prior to modification with the metal ion.
20. The substrate of claim 17 , wherein the zeta potential of the modified nanoparticles is greater than the zeta potential of the first nanoparticles prior to modification.
21. The substrate of claim 20 , wherein the zeta potential of the modified particles is from about −5 millivolts to about −15 millivolts.
22. The substrate of claim 17 , wherein the metal ion is adsorbed onto a surface of the first nanoparticles.
23. The substrate of claim 17 , wherein the metal ion forms a coordinate or covalent bond with the first nanoparticles.
24. The substrate of claim 17 , wherein the first nanoparticles have a surface area of at least about 100 square meters per gram.
25. The substrate of claim 17 , wherein the first and second nanoparticles have a size of less than about 500 nanometers.
26. The substrate of claim 17 , wherein the first nanoparticles comprise silica.
27. The substrate of claim 17 , wherein the second nanoparticles comprise alumina.
28. The substrate of claim 27 , wherein the alumina is coated onto silica.
29. The substrate of claim 17 , wherein the metal ion includes copper, silver, gold, iron, manganese, or combinations thereof.
30. The substrate of claim 17 , wherein the substrate contains polyolefin fibers.
31. The substrate of claim 17 , wherein the substrate is a spunbond web, meltblown web, or combination thereof.
32. The substrate of claim 17 , wherein the substrate contains cellulosic fibers.
33. The substrate of claim 17 , wherein the modified nanoparticles constitute from about 0.1 to about 10 wt.% of the substrate.
34. A personal care product comprising the substrate of claim 17 .
35. Protective barrier clothing comprising the substrate of claim 17 .