Polymer beads incorporating solid particulate material

1. Polymer beads having:

(i) a polymeric matrix comprising polymerised monomer residues of (a) at least one monoethylenically unsaturated monomer, and (b) at least one crosslinking monomer having at least two ethylenically unsaturated groups separated by at least 4 consecutive acyclic atoms, and

(ii) a pitted surface comprising porogen-derived pits,

wherein the polymeric matrix has distributed therethrough magnetic solid particulate material and polymeric porogen, and wherein the internal polymeric matrix of the beads has a porogen-derived porosity less than that of the pitted surface.

2. The polymer beads according to claim 1 , wherein the at least one crosslinking monomer is selected from ethylene glycol dimethacrylate, poly(ethylene glycol) dimethacrylate, methylene bisacrylamide, triethylene glycol diacrylate, triethylene glycol dimethacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, glycerol diacrylate, glycerol dimethacrylate, 1,3-butanediol diacrylate and 1,3-butanediol dimethacrylate, 1,3-propanediol diacrylate, 1,3-propanediol dimethacrylate, 1,3-pentanediol diacrylate, 1,3-pentanediol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, hexamethylene glycol diacrylate, hexamethylene glycol dimethacrylate, decamethylene glycol diacrylate, decamethylene glycol dimethacrylate, 2,2-dimethylolpropane diacrylate, 2,2-dimethylolpropane dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, 2,2-di(p-hydroxyphenyl)propane diacrylate, 2,2-di(p-hydroxyphenyl)propane dimethacrylate, 2,2,4-trimethyl-1,3-pentanediol diacrylate, 2,2,4-trimethyl-1,3-pentanediol dimethacrylate, tetraethylene glycol diacrylate, tetraethylene glycol dimethacrylate, and combinations thereof.

3. The polymer beads according to claim 1 , wherein the at least one crosslinking monomer is selected from trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, glycerol triacrylate, glycerol trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, tris(2-hydroxy ethyl) isocyanurate triacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane trimethacrylate, propoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane trimethacrylate, ethoxylated glycerol triacrylate, ethoxylated glycerol trimethacrylate, propoxylated glycerol triacrylate, propoxylated glycerol trimethacrylate, ethoxylated pentaerythritol triacrylate, ethoxylated pentaerythritol trimethacrylate, propoxylated pentaerythritol triacrylate, propoxylated pentaerythritol trimethacrylate, ethoxylated pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetramethacrylate, propoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetramethacrylate, and combinations thereof.

4. The polymer beads according to claim 1 , wherein the magnetic solid particulate material is selected from maghemite, magnetite, chromium dioxide, and combinations thereof.

5. The polymer beads according to claim 1 , wherein the polymeric porogen is selected from poly(vinyl methyl ether), poly(ethylene oxide), poly(vinyl acetate), poly(methyl methacrylates), poly(vinyl acetate co-maleic or fumaric acid and esters), fatty alcohol ethoxylates, fatty alcohol alkoxylates, alcohol alkoxylates, fatty acid ethoxylates, castor oil ethoxylates, fatty amine ethoxylates, alkylphenol ethoxylates, alkyl ethoxy carboxylic acids, and combinations thereof.

6. The polymer beads according to claim 1 , wherein the polymeric matrix is functionalised with functional groups that provide the polymer beads with ion exchange capacity.

7. The polymer beads according to claim 6 , wherein the ion exchange capacity is provided by amine or acid functional groups.

8. A method of treating an aqueous solution, the method comprising contacting said aqueous solution with polymer beads according to claim 1 .

9. A method of removing dissolved organic carbon from an aqueous solution, the method comprising (i) contacting said aqueous solution with polymer beads according to claim 1 , and (ii) removing from the aqueous solution polymer beads having dissolved organic carbon adsorbed thereon.

10. A method of removing ions from an aqueous solution, said method comprising (i) contacting said aqueous solution with polymer beads according to claim 6 , and (ii) removing from the aqueous solution polymer beads that have undergone ion exchange with the ions to be removed.