Sorting two-dimensional nanomaterials by thickness
The Present teachings provide, in part, methods of separating two-dimensional nanomaterials by atomic layer thickness. In certain embodiments, the present teachings provide methods of generating graphene nanomaterials having a controlled number of atomic layer(s).
1. A method for separating graphene nanomaterials by thickness, the method comprising:
sonicating pristine graphite in a first fluid medium to provide a graphene composition;
centrifuging the graphene composition in contact with an aqueous second fluid medium comprising a density gradient, wherein the graphene composition comprises one or more surface active components and a polydisperse population of graphene nanomaterials comprising monolayer graphene, bilayer graphene, trilayer graphene, and n-layer graphene, wherein n is an integer in the range of 4 to 10; and
separating the graphene composition into two or more separation fractions each comprising a subpopulation of graphene nanomaterials from the polydisperse population, wherein the subpopulation in at least one of the two or more separation fractions comprises greater than 50% of monolayer graphene, bilayer graphene, trilayer graphene, or combinations thereof.
2. The method of claim 1 , wherein the subpopulation in at least one of the two or more separation fractions comprises greater than 50% of the monolayer graphene, bilayer graphene, or combinations thereof.
3. The method of claim 1 , wherein the one or more surface active components comprise an amphiphilic compound having a planar core and one or more anionic groups.
4. The method of claim 3 , wherein the one or more surface active components comprise an amphiphilic compound having a sterane core and one or more anionic groups selected from hydroxyls, carboxylates, sulfates, sulfonates, and combinations thereof.
5. The method of claim 1 , wherein the one or more surface active components comprise a bile salt.
6. The method of claim 1 , wherein one or more surface active components comprise a bile salt selected from sodium cholate, sodium deoxycholate, sodium chenodeoxycholate, sodium taurodeoxycholate, sodium glycochenodeoxycholate, sodium ursodeoxycholate, and sodium glycoursodeoxycholate.
7. A method for separating graphene nanomaterials by thickness, the method comprising:
centrifuging a graphene composition in contact with an aqueous fluid medium comprising a density gradient, wherein the graphene composition comprises one or more surface active components and a polydisperse population of graphene nanomaterials comprising monolayer graphene, bilayer graphene, trilayer graphene, and n-layer graphene, wherein n is an integer in the range of 4 to 10; and
separating the graphene composition into two or more separation fractions each comprising a subpopulation of graphene nanomaterials from the polydisperse population, wherein the subpopulation in at least one of the two or more separation fractions comprises greater than 50% of monolayer graphene, bilayer graphene, trilayer graphene, or combinations thereof.
8. The method of claim 7 , wherein the subpopulation in at least one of the two or more separation fractions comprises greater than 50% of the monolayer graphene, bilayer graphene, or combinations thereof.
9. The method of claim 7 , wherein the one or more surface active components comprise an amphiphilic compound having a planar core and one or more anionic groups.
10. The method of claim 9 , wherein the one or more surface active components comprise an amphiphilic compound having a sterane core and one or more anionic groups selected from hydroxyls, carboxylates, sulfates, sulfonates, and combinations thereof.
11. The method of claim 7 , wherein the one or more surface active components comprise a bile salt.
12. The method of claim 7 , wherein one or more surface active components comprise a bile salt selected from sodium cholate, sodium deoxycholate, sodium chenodeoxycholate, sodium taurodeoxycholate, sodium glycochenodeoxycholate, sodium ursodeoxycholate, and sodium glycoursodeoxycholate.
13. A method for separating graphene nanomaterials by thickness, the method comprising:
centrifuging a graphene composition in contact with an aqueous fluid medium comprising a density gradient, wherein the graphene composition comprises one or more surface active components comprising an amphiphilic compound comprising a planar organic group, and a polydisperse population of graphene nanomaterials comprising monolayer graphene, bilayer graphene, trilayer graphene, and n-layer graphene, wherein n is an integer in the range of 4 to 10; and
separating the graphene composition into two or more separation fractions each comprising a subpopulation of graphene nanomaterials from the polydisperse population, wherein the subpopulation in at least one of the two or more separation fractions comprises greater than 50% of monolayer graphene, bilayer graphene, trilayer graphene, or combinations thereof.
14. The method of claim 13 , wherein the one or more surface active components is a non-ionic block copolymer of oxyethylene and oxypropylene.
15. The method of claim 13 , wherein the subpopulation in at least one of the two or more separation fractions comprises greater than 50% of the monolayer graphene, bilayer graphene, or combinations thereof.
16. The method of claim 15 , wherein the one or more surface active components is a non-ionic block copolymer of oxyethylene and oxypropylene.