Patent ID: 8586097

Claim:
A method of preparing a core-shell composite comprising a polymeric core component and a crosslinked polymeric shell component, the method comprising preparing a first phase comprising a polymeric core component and a shell polymer in a first liquid, the shell polymer being substantially dissolved in the first liquid, comprising hydrating the core component in the first liquid, the first liquid being an aqueous solution, the core component comprising a hydrophilic core polymer, dissolving the shell polymer in the aqueous solution, the shell polymer being a hydrophilic shell polymer, allowing the shell polymer to interact with a surface of the hydrated core component to form a hydrated core-shell intermediate, preparing a second phase comprising a crosslinking agent in a second liquid, the second liquid being substantially immiscible with the first liquid, combining the first phase and the second phase to form a heterogeneous multiphase media, crosslinking the shell polymer with the crosslinking agent on a surface of the core component to form the core-shell composite in the multiphase media, and removing at least a portion of the first liquid from the heterogeneous multiphase media during crosslinking; wherein the core component comprises a cation exchange polymer and the shell polymer comprises a net positively charged crosslinked amine polymer comprising amine moieties and the core-shell particle has a size of 1 μm to 500 μm and a binding capacity for potassium of at least 1.5 mmol/g at a pH greater than 5.5.