Guanidine-functionalized particles and methods of making and using
View Patent ↗Guanidine-functionalized particles and methods of making and using such particles.
1. A guanidine-functionalized silica gel particle, comprising:
a silica gel particle comprising at least one ligand comprising a guanidine group, the ligand comprising the formula —O n Si—S m -G,
where —O is an oxygen atom that is covalently bonded to the surface of the silica gel particle,
n is 1, 2 or 3,
S is a spacer group comprising a backbone with m atoms,
m is 2-16, inclusive,
G is a guanidine group of the formula NH—C(NH)—NH 2 ,
wherein the guanidine group is charged and comprises an associated counterion and wherein the counterion does not comprise a halogen,
and wherein the silica gel particle comprises a particle size of about 25-100 microns and a pore size of about 60-2000 Angstroms.
2. The particle of claim 1 wherein all m atoms of the backbone of the spacer group S are carbon atoms.
3. The particle of claim 2 wherein m=3.
4. The particle of claim 1 wherein the spacer group S comprises a secondary amine.
5. The particle of claim 1 wherein the guanidine group is the reaction product of a primary amine and O-methylisourea hemisulfate.
6. The particle of claim 1 wherein the ligand is the reaction product of one or more hydroxyl groups of the silica particle with one or more reactive groups of a silane coupling agent moiety of the ligand.
7. The particle of claim 1 wherein the counterion that is associated with the guanidine group is a sulfate ion.
8. The particle of claim 1 wherein the counterion that is associated with the guanidine group is a bisulfate ion.
9. The particle of claim 1 wherein the counterion that is associated with the guanidine group is a hydroxide ion.
10. The particle of claim 1 wherein residual hydroxyl groups are present on the surface of the particle.
11. The particle of claim 1 wherein each ligand has only a single guanidine group.
12. The particle of claim 1 wherein the guanidine group-containing ligands are the only ligands present on the particle.
13. A fluid-purification device comprising a plurality of guanidine-functionalized silica gel particles, each guanidine-functionalized silica gel particle comprising at least one ligand comprising a guanidine group, the ligand comprising the formula —O n Si—S m -G,
where —O is an oxygen atom that is covalently bonded to the surface of the silica gel particle,
n is 1, 2 or 3,
S is a spacer group comprising a backbone with m atoms,
m is 2-16, inclusive,
G is a guanidine group of the formula NH—C(NH)—NH 2 ,
wherein the guanidine group is charged and comprises an associated counterion that does not comprise a halogen,
and wherein the guanidine-functionalized silica gel particles are entrapped within a container that is configured to accept a fluid to be purified and to allow a purified fluid to be removed therefrom.
14. The fluid-purification device of claim 13 wherein the guanidine group is the reaction product of a primary amine and O-methylisourea hemisulfate.
15. The fluid-purification device of claim 13 wherein the silica gel particles comprise a particle size of about 25-100 microns and a pore size of about 60-2000 Angstroms.
16. The fluid-purification device of claim 13 wherein the ligand is the reaction product of one or more hydroxyl groups of the silica particle with one or more reactive groups of a silane coupling agent moiety of the ligand.
17. The fluid-purification device of claim 13 wherein the counterion that is associated with the guanidine group is a sulfate ion.
18. The fluid-purification device of claim 13 wherein the counterion that is associated with the guanidine group is a bisulfate ion.
19. The fluid-purification device of claim 13 wherein the counterion that is associated with the guanidine group is a hydroxide ion.