Uniform gel beads 3 mm in diameter were obtained by the suspension polymeri
zation of an amine functionalized monomer, N-3-(dimethyl amino)propyl-metha
crylamide (DMAPM). The polymerization of DMAPM in the form of uniform dropl
ets could be achieved at room temperature in an aqueous dispersion medium b
y using Ca-alginate gel as the polymerization mold. In this preparation, po
tassium persulfate/tetramethyl ethylenediamine and sodium alginate/calcium
chloride were used as the redox initiator and the stabilizer systems, respe
ctively. The crosslinked DMAPM gel beads exhibited pH-sensitive, reversible
swelling-deswelling behavior. The uniform gel beads were also obtained by
the copolymerization of DMAPM and acrylamide (AA) in the same polymerizatio
n system. Although copolymer gel beads with higher pH sensitivities were ob
tained with increasing feed concentration of DMAPM, the total monomer conve
rsion decreased. Crosslinked DMAPM and DMAPM-AA copolymer gel beads were ut
ilized as sorbents for DNA adsorption. The gel beads produced with higher D
MAPM feed concentration exhibited higher equilibrium DNA adsorption capacit
y. The DNA equilibrium adsorption capacities up to 50 mg DNA/g dry gel coul
d be achieved with the crosslinked DMAPM gel beads. This value was reasonab
ly higher relative to the previously reported adsorption capacities of know
n sorbents. (C) 2000 John Wiley & Sons, Inc.