High capacity perchlorate-selective resins from hyperbranched macromolecules
A resin is provided for selectively binding to perchloride and related anions (e.g., TcO 4 − , ReO 4 − and I − ) in aqueous solution. The resin may take the form of microparticles or beads. The beads are prepared by cross-linking macromolecules such as hyperbranched PEI, and quaternizing the amines with hydrocarbon substituents.
1. A perchlorate-selective microparticle prepared by a method comprising:
(a) providing a water soluble branched molecule comprising polyethyleneimine (PEI) with a molecular weight in excess of 1500 Da, the molecule comprising a plurality of branches including a plurality of tertiary amine moieties, a plurality of primary amine moieties, and optionally one or more secondary amine moieties;
(b) reacting the branched molecule with a cross-linking agent in an inverse suspension of toluene and water stabilized by a surfactant to produce a cross-linked resin matrix in the form of a spherical microparticle comprising a plurality of primary, secondary, and/or tertiary amine moieties;
(c) quaternizing the plurality of primary, secondary, and/or tertiary amine moieties by reacting a haloalkane reactant with the amine moieties to provide quaternary substitution of the amine moieties with alkyl moieties; and
(d) during and/or after step (b), removing water from the microparticle so that the water content of the microparticle is less than about 50% water by weight;
wherein the perchlorate-selective microparticle is selective for perchlorate and comprises a plurality of branched macromolecular structures (A) and a plurality of cross-linking moieties, wherein the plurality of A is cross-linked through the plurality of cross-linking moieties, and wherein each A comprises a plurality of branches and a plurality of terminal functional groups;
wherein each of the plurality of branches comprises an N,N,N-substituted (quaternary) n-aminoalkyl moiety comprising three substituent moieties, and wherein each of the plurality of branches optionally comprises one or more N,N-substituted (tertiary) n-aminoalkyl moieties comprising two substituent moieties;
wherein each of the substituent moieties comprises one of the following:
(a) another of said plurality of branches;
(b) one of the plurality of terminal functional groups; or
(c) one of the cross-linking moieties attached at a first cross-linking end, wherein the cross-linking moiety further comprises a second cross-linking end, by which the moiety is also one of the substituent moieties of one of the plurality of branches at a different location within the microparticle;
wherein the cross-linking agent comprises a combination of epichlorohydrin (—CH 2 —CHOH—CH 2 —) and 1-bromo-3-chloropropane (—CH 2 —CH 2 —CH 2 —); and
wherein the surfactant comprises sodium dodecyl benzyl sulfonate (SDBS).
2. The microparticle of claim 1 , wherein each of the plurality of terminal functional groups are alkyl moieties having no less than two and no more than six carbon atoms.
3. The microparticle of claim 1 , wherein the strong-base exchange capacity (SBEC) of the microparticle is greater than about 1.5 eq/L.
4. The microparticle of claim 3 , wherein the strong-base exchange capacity (SBEC) of the microparticle is greater than about 2.0 eq/L.
5. The microparticle of claim 4 , wherein the strong-base exchange capacity (SBEC) of the microparticle is greater than about 2.5 eq/L.
6. The microparticle of claim 1 , wherein the water content of the microparticle is less than about 40% and greater than about 25% by weight.
7. The microparticle of claim 2 , wherein the haloalkane reactant is derived from iodoethane, bromobutane, or 1-bromohexane.
8. The microparticle of claim 1 , wherein the microparticle selectively binds ClO 4 − in an aqueous media.
9. The microparticle of claim 1 , wherein the microparticle is used for water treatment.
10. A perchlorate-selective microparticle prepared by a method comprising:
(a) providing a water soluble branched molecule comprising polyethyleneimine (PEI) with a molecular weight of 1800, 10000 or 25000 Da, the molecule comprising a plurality of branches including a plurality of tertiary amine moieties, a plurality of primary amine moieties, and optionally one or more secondary amine moieties;
(b) reacting the branched molecule with a cross-linking agent comprising a combination of epichlorohydrin (—CH 2 —CHOH—CH 2 —) and 1-bromo-3-chloropropane (—CH 2 —CH 2 —CH 2 —) in an inverse suspension of toluene and water stabilized by a surfactant comprising sodium dodecyl benzyl sulfonate (SDBS) to produce a cross-linked resin matrix in the form of a spherical microparticle comprising a plurality of primary, secondary, and/or tertiary amine moieties;
(c) quaternizing the plurality of primary, secondary, and/or tertiary amine moieties by reacting a haloalkane reactant with the amine moieties to provide quaternary substitution of the amine moieties with alkyl moieties; and
(d) during and/or after step (b), removing water from the microparticle so that the water content of the microparticle is less than about 50% water by weight;
wherein the perchlorate-selective microparticle comprises a plurality of branched macromolecular structures (A) and a plurality of cross-linking moieties, wherein the plurality of A is cross-linked through the plurality of cross-linking moieties, and wherein each A comprises a plurality of branches and a plurality of terminal functional groups;
wherein each of the plurality of branches comprises an N,N,N-substituted (quaternary) n-aminoalkyl moiety comprising three substituent moieties, and wherein each of the plurality of branches optionally comprises one or more N,N-substituted (tertiary) n-aminoalkyl moieties comprising two substituent moieties;
wherein each of the substituent moieties comprises one of the following:
(a) another of said plurality of branches;
(b) one of the plurality of terminal functional groups; or
(c) one of the cross-linking moieties attached at a first cross-linking end, wherein the cross-linking moiety further comprises a second cross-linking end, by which the moiety is also one of the substituent moieties of one of the plurality of branches at a different location within the microparticle.