Compositions of transition metal species in dense phase carbon dioxide and methods of use thereof
AssigneeMicell Technologies, Inc.
InventorsJames P. DeYoung, James B. McClain, Stephen M. Gross, Mark I. Wagner
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Abstract
Compositions useful for cleaning metal from a substrate or coating metal onto a substrate are described: Such compositions comprise (a) a densified carbon dioxide continuous phase; (b) a polar discrete phase in said carbon dioxide continuous phase; (c) a metal in said discrete phase (i.e., a metal removed from the substrate, or to be coated onto the substrate); (d) at least one ligand in said continuous phase, said discrete phase, or both said continuous and said discrete phase.
Claims78
A composition comprising:
- (a) a densified carbon dioxide continuous phase;
- (b) a polar discrete phase in said carbon dioxide continuous phase;
- (c) a metal ion in said discrete phase;
- (d) at least one ligand in said continuous phase, said discrete phase, or both said continuous and said discrete phase.
A method of cleaning metal from a substrate, comprising the steps of:
- (a) providing a substrate having a surface portion to be cleaned of metal;
- (b) providing a densified carbon dioxide cleaning composition, the composition comprising carbon dioxide as a continuous phase, a discrete polar phase, and at least one ligand solubilized in said discrete phase, said continuous phase or both said discrete phase and said continuous phase;
- (c) immersing the surface portion in said densified carbon dioxide cleaning composition so that said metal associates with said ligand;
- and then
- (d) removing the cleaning composition from the surface portion so that said metal is thereby cleaned from said surface portion.
A method of coating a metal onto a substrate, comprising the steps of:
- (a) providing a substrate having a surface portion to be coated with a metal;
- (b) providing a densified carbon dioxide composition, said composition comprising carbon dioxide as a continuous phase, a polar discrete phase, a metallic species and at least one ligand dissolved in said discrete phase, said continuous phase, or both said discrete phase and said continuous phase;
- (c) immersing the surface portion in said carbon dioxide composition;
- (d) adding a reducing agent to said carbon dioxide composition so that the metallic species is chemically reduced, separates from said ligand and deposits on said surface portion;
- and then
- (e) removing said carbon dioxide composition from the surface portion to leave metal deposited on said surface portion.
A method according to claim of 60 where said reduced metal species is preferentially deposited onto said metallic surface.
A method according to 55, wherein said deposited metal comprises a particulate.
A method according to 77, wherein said particulate is between 5 and 100 nm in size.
Dependencies are inferred from the claim text.