Sulfur scavenging materials
Materials which react with (“scavenge”) sulfur compounds, such as hydrogen sulfide and mercaptans, are useful for limiting sulfur-induced corrosion. Surface-modified particles incorporating a hexahydrotriazine moiety are disclosed and used as sulfur scavengers. These surface-modified particles are used a filter media in fixed filter systems and as additives to fluids including sulfur compounds. The hexahydrotriazine moiety can react with sulfur compounds in such a manner as to bind sulfur atoms to the surface-modified particles, thus allowing removal of the sulfur atoms from fluids such as crude oil, natural gas, hydrocarbon combustion exhaust gases, sulfur polluted air and water. The surface-modified particles may, in general, be sized to allow separation of the particles from the process fluid by sedimentation, size-exclusion filtration or the like.
1. A surface-attached molecule, comprising:
wherein:
LG is a linking group covalently bonded to a nitrogen atom of a hexahydrotriazine moiety and a surface, and
AR is an electron-donating group.
2. The surface-attached molecule of claim 1 , wherein the electron-donating group includes an aromatic moiety.
3. The surface-attached molecule of claim 1 , wherein the electron-donating group is a N,N-dimethylamino-p-phenyl group.
4. The surface-attached molecule of claim 1 , wherein the electron-donating group is a phenyl group.
5. The surface-attached molecule of claim 1 , wherein the electron-donating group is one of a methyl ether, a pyrene, a hydroxyl group, a sulfhydryl group, or an alkylthio group.
6. The surface-attached molecule of claim 1 , wherein the linking group is a straight-chain alkyl group including at least three carbon atoms.
7. The surface-attached molecule of claim 1 , wherein the linking group is an alkyl silyl group.
8. The surface-attached molecule of claim 7 , wherein the alkyl silyl group is a propyltriethoxysilyl group.
9. The surface-attached molecule of claim 1 , wherein AR is at least one of the following:
10. The surface-attached molecule of claim 1 , wherein the surface is an outer surface of a silica particle.
11. A surface-attached molecule, comprising:
wherein:
LG is a linking group covalently bonded to a nitrogen atom of a hexahydrotriazine moiety and a surface, and
AR is an electron-donating group, the electron-donating group comprising an aromatic moiety.
12. The surface-attached molecule of claim 11 , wherein the electron-donating group is a N,N-dimethylamino-p-phenyl group.
13. The surface-attached molecule of claim 11 , wherein the electron-donating group is a phenyl group.
14. The surface-attached molecule of claim 11 , wherein the linking group comprises a straight-chain alkyl group including at least three carbon atoms.
15. The surface-attached molecule of claim 11 , wherein the linking group comprises an alkyl silyl group.
16. The surface-attached molecule of claim 15 , wherein the alkyl silyl group is a propyltriethoxysilyl group.
17. The surface-attached molecule of claim 11 , wherein AR is at least one of the following:
18. The surface-attached molecule of claim 11 , wherein the surface is an outer surface of a silica particle.
19. A surface-attached molecule, comprising:
wherein:
LG is a linking group covalently bonded to a nitrogen atom of a hexahydrotriazine moiety and a surface, wherein the linking group comprises a straight-chain alkyl group having at least three carbon atoms, and
AR is an electron-donating group, the electron-donating group comprising an aromatic moiety.
20. The surface-attached molecule of claim 19 , wherein the surface is an outer surface of a silica particle.