Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – From aldehyde or derivative thereof as reactant
Reexamination Certificate
1999-11-22
2002-01-01
Woodward, Ana (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
From aldehyde or derivative thereof as reactant
C525S419000, C528S271000, C528S328000, C528S367000
Reexamination Certificate
active
06335420
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to polyamide ligand-containing polymeric resins which are polymerized and/or crosslinked and methods of using the same for removing, separating, and/or concentrating certain desired metal ions from solutions, even when the desired ions are in the presence of other metal ions and/or hydrogen ions at much higher concentrations.
BACKGROUND OF THE INVENTION
Effective methods for the separation and recovery of particular ions such as the transition, post-transition, and alkaline earth metal ions from solution mixtures containing these and other metal ions are of great importance in modern technology. Particularly, it is difficult to separate and recover certain metal ions such as Cd
2+
, Pb
2+
, Ag
+
, Ni
2+
, Co
2+
, Fe
3+
, Cu
2+
, Sr
2+
, and/or Ca
2+
from the presence of even moderate amounts of hydrogen ion (H
+
). It is also very difficult to remove these desired metal ions when present at low concentrations in solutions that contain other, non-desired metal ions at much greater concentrations. Thus, there is a real need for a composition of matter and an associated method that may be used for selectively separating certain transition, post-transition, and alkaline earth metal ions from other non-desirable ions.
It is known that ethylenediaminetetraacetamide (EDTAA), diethylenetriaminepentaacetamide (DTPAA), and nitrilotriacetamide (NTAA) form strong complexes with various metal ions in solution. These molecules may be shown as Formulas 1-3 respectively below:
J. M. Grana-Molares, C. Baluja-Santos, A. Alvarez-Devesa and F. Bermejo-Martinez,
Etude Spectrophotometrigue des Complexes du Cobalt
(
III
)
avec les Amides de l'EDTA et du DTPA
, Analysis, Volume 7, 249-252 (1979) reported on the synthesis of EDTAA and DTPAA and their ability to complex Co(III) as shown by a spectrophotometric technique. In a different study, L. Przyborowski,
Complex Compounds of Amides and Thioamides of Aminopolycarboxylic Acids, Part III. Synthesis, Properties and Copper
(
II
)
Complexes of Nitrilotriacetotriamide and Ethylenediaminetetraacetotetraamide
, Roczniki Chemii, Volume 44, 1883-1893 (1970) showed that NTAA and EDTAA could be prepared by modifying known methods and that Cu(II) formed strong complexes with NTAA.
More recently, a great deal of research has been done in the synthesis and metal ion complexation properties of polyamide-containing azacrown ethers such as those containing acetamide, propionamide, and peptide side arms. R. Kataky, K. E. Matthes, P. E. Nicholson, D. Parker and H-J. Buschmann,
Synthesis and Binding Properties of Amide
-
Functionalized Polyazamacrocycles
, Journal of the Chemical Society, Perkin Transactions 2, 1425-1432 (1990) reported on the synthesis and complexation properties of per-N-(dimethylacetamido)-substituted triaza-9-crown-3, aza-12-crown-4, diaza-12-crown-4, and tetraaza-12-crown-4. The ligating agents 1,4,7,10-tetrakis(N,N-dimethylacetamido)-1,4,7,10-tetraazacyclododecane and 1,7-dioxo-4,10-bis(N,N-dimethylacetamido)-4,10-diazacyclododecane are two chemical structures that were synthesized and which are representative of polyamide-containing ligating agents of the present invention. These ligating agents are shown respectively below in Formulas 4 and 5:
The diamide of Formula 5 was shown to form complexes with all of the alkali metal and alkaline earth metal cations. Further, this diamide was shown to have significant selectivity for Ca
2+
over the other cations studied. However, a diamide similar to that of Formula 5, but containing one more methylene group in each amide-containing arm (thus, having two N,N-dimethylpropioamido substituents), was shown to form weaker complexes with these same metal ions.
Further studies of amide ligands, such as those depicted by formulas 4 and 5, have concluded that the size of the metal ion-ligand chelate ring determines the strength of the interaction between the ligand and the metal ions. For example, a five-membered ring favored the smaller cations over a six-membered ring. Representative of fully chelated metals (Me) having five- and six-membered amide rings attached are shown in Formulas 6 and 7 respectively below:
H. Maumela, R. D. Hancock, L. Carlton, and J. H. Reibenspies and K. P. Wainwright,
The Amide Oxygen as a Donor Group. Metal Ion Complexing Properties of Tetra
-
N
-
Acetamide Substituted Cyclen: A Crystallographic, NMR, Molecular Mechanics and Thermodynamic Study
, Journal of the American Chemical Society, Volume 117, 6698-6707 (1995), reported the synthesis of 1,4,7,10-tetraazacyclododecane (DOTAM) which is the unsubstituted amide analogue of the tetraamide of Formula 4. DOTAM is capable of forming complexes with a host of metal ions including many transition and post-transition metal ions. DOTAM also forms strong complexes with Cd
2+
and Pb
2+
, even at pH levels of as low as 0.3 which is equivalent to a hydrogen ion concentration of 0.5 Molar. DOTAM may be represented by Formula 8 below:
The articles cited above disclose procedures for synthesizing and demonstrating limited useful complexation properties of polyamide-containing ligand molecules. However, researchers have not previously been able to incorporate polyamide-containing ligands into solid phase separation systems. This is significant because these polyamide-containing ligands merely act as a solute in solution by completing with selected ions, but provide no effective means for ion separation.
The use of polymeric resins for selective removal of ions is not a new concept of itself. In U.S. Pat. No. 5,656,702, the use of poly(hydroxyarylene) polymeric resins is disclosed for removing alkali metals, particularly cesium, from industrial streams. However, never before have polyamide ligand-containing polymeric resins been successfully synthesized that can be used in a solid phase separation system to concentrate and remove desired metal ions such as members selected from the group consisting of Cd
2+
, Pb
2+
, Ag
+
, Ni
2+
, Co
2+
, Fe
3+
, Cu
2+
, Sr
2+
, and/or Ca
2+
from source solutions.
SUMMARY OF THE INVENTION
The present invention is drawn to polyamide ligand-containing polymeric resins and methods of using the same for removing, separating, and/or concentrating certain desired divalent metal ions including transition, post-transition, and alkaline earth metal ions from source solutions. The unique composition of matter of this invention is a polyamide ligand-containing polymeric resin which has been polymerized and/or crosslinked. These resins are generally a reaction product of a hydroxymethylated polyamide ligand and a polymerization and/or crosslinking agent. Specifically, the polymeric resins of the present invention are comprised of from 10 to 50,000 polyamide ligand units wherein each polyamide ligand unit is defined by three or more amide groups, preferably from three to eight amide groups, and two or more amine nitrogen donor atoms separated by at least two carbons.
The present invention is particularly useful for the removing of ions selected from the group consisting of Cd
2+
, Pb
2+
, Ag
+
, Ni
2+
, Co
2+
, Fe
3+
, Cu
2+
, Sr
2+
, Ca
2+
, and combinations thereof from source solutions. This is true whether the desired ions are present at very low or very high concentrations, i.e., from ppb to g/l.
The concentration of desired ions is accomplished by forming a complex of desired ions with the polyamide ligand-containing polymeric resins by flowing a source solution containing the desired ions through a column packed with the polymeric resin beads or granules. The metal ion and the polyamide ligand-containing polymeric resins are then decoupled by flowing a receiving liquid through the column (in much smaller volume than the volume of source solution passed through the column) to removing, separating, and/or concentrating the desired ions in the receiving liquid solution. The receiving liquid or recover
Bruening Ronald L.
Krakowiak Krzysztof E.
IBC Advanced Technologies, Inc.
Thorpe North & Western LLP
Woodward Ana
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