title: Branched polymeric media: boron-chelating resins from hyperbranched polyethylenimine.
abstract: Extraction of boron from aqueous solutions using selective resins is important in a variety of applications including desalination, ultrapure water production, and nuclear power generation. Today's commercial boron-selective resins are exclusively prepared by functionalization of styrene-divinylbenzene (STY-DVB) beads with N-methylglucamine to produce resins with boron-chelating groups. However, such boron-selective resins have a limited binding capacity with a maximum free base content of 0.7 eq/L, which corresponds to a sorption capacity of 1.16 ± 0.03 mMol/g in aqueous solutions with equilibrium boron concentration of ∼70 mM. In this article, we describe the synthesis and characterization of a new resin that can selectively extract boron from aqueous solutions. We show that branched polyethylenimine (PEI) beads obtained from an inverse suspension process can be reacted with glucono-1,5-D-lactone to afford a resin consisting of spherical beads with high density of boron-chelating groups. This resin has a sorption capacity of 1.93 ± 0.04 mMol/g in aqueous solution with equilibrium boron concentration of ∼70 mM, which is 66% percent larger than that of standard commercial STY-DVB resins. Our new boron-selective resin also shows excellent regeneration efficiency using a standard acid wash with a 1.0 M HCl solution followed by neutralization with a 0.1 M NaOH solution.
authors: Materials and Process Simulation Center, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States.
authors: Himanshu
authors: H
authors: Mishra
authors: Changjun
authors: C
authors: Yu
authors: Dennis P
authors: DP
authors: Chen
authors: William A
authors: WA
authors: Goddard
authors: Nathan F
authors: NF
authors: Dalleska
authors: Michael R
authors: MR
authors: Hoffmann
authors: Mamadou S
authors: MS
authors: Diallo
mesh_terms: D001895:Boron / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D011108:Polymers; D011094:Polyethyleneimine; D001895:Boron