Synthesis of macroporous polymer through heterogeneous polymerization by redox initiator and application as scaffold for Pd nanoparticles

Heterogeneous polymerization of the binary hydrophilic/hydrophobic monomers initiated by the redox pair to synthesize macroporous amphiphilic copolymers is reported. This strategy employs the initiator of the hydrophilic/hydrophobic redox pair of K2S2O8/1-octylamine or the hydrophilic/hydrophilic redox pairs of K2S2O8/diethylamine and K2S2O8/Na2SO3 to initiate the polymerization on the O/W emulsion interface at mild temperature. Following this strategy, both the macroporous poly(methyl methacrylate-co-methacrylic acid) with the pore size ranging from 80 to 400 nm and the macroporous poly(styrene-co-methacrylic acid) with the pore size at about 180–190 nm are synthesized. The synthesized macroporous amphiphilic copolymers are demonstrated to be suitable scaffold for Pd nanoparticles. The immobilization of Pd nanoparticles with the Pd content up to 8.5 wt.% and with the Pd nanoparticle size ranging from 4.6 to 7.1 nm is achieved. The proposed strategy is believed to be a valid method to synthesize porous amphiphilic copolymer.

• Heterogeneous polymerization initiated by redox pair under mild conditions is performed. • Synthesis of macroporous amphiphilic copolymer is achieved. • Macroporous copolymers are demonstrated to be suitable scaffold for Pd nanoparticles. • Up to 8.5 wt.% Pd is immobilized on the macroporous copolymer.