Monodisperse-porous N-methyl-D-glucamine functionalized poly(vinylbenzyl chloride-co-divinylbenzene) beads as boron selective sorbent

To generate a new sorbent with high boron adsorption capacity, we synthesized monodisperse‐porous poly(vinylbenzyl chloride‐co‐divinylbenzene), poly(VBC‐co‐DVB), beads 8.5 μm in size by a new “modified seeded polymerization” technique. By using their chloromethyl functionality, the beads were derivatized by a simple, direct reaction with a boron‐selective ligand, N‐methyl‐D‐glucamine (NMDG). The selection of poly(VBC‐co‐DVB) beads as a starting material allowed to obtain high boron sensitive‐ligand density on the beads depending on their high chloromethyl content. In the batch adsorption runs performed using NMDG‐attached poly(VBC‐co‐DVB) beads as sorbent, boron removal was efficiently performed in a wide pH range between 4 and 11. Quantitative boron removal was observed with the sorbent concentration of 4 g/L. In the same runs, plateau value of equilibrium adsorption isotherm was obtained as 14 mg boron/g beads. Relatively higher boron adsorption was explained by high ligand density and high specific surface area of the sorbent. Boron adsorption isotherms were analyzed using Langmuir and Freundlich models. In the kinetic runs performed for boron removal, the equilibrium was attained within 10 min at a value of 98%. The fast kinetic behavior was explained by the smaller particle size and enhanced porosity of the new sorbent. Infinite solution volume model and unreacted core model were used to evaluate boron adsorption onto the NMDG‐attached poly(VBC‐co‐DVB) beads. The results indicated that the adsorption process is controlled by the particle‐diffusion step. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012