Controlled synthesis of silver nanoparticles from polyoxometalates-immobilized poly(4-vinylpyridine) brushes

We extend the application of polymer brush to the synthesis of silver nanoparticles. Polymer brushes can efficiently prevent the aggregation of the prepared the nanoparticles and allow the tailored synthesis of Ag nanoparticles. [Display omitted] This contribution reports the immobilization of polyoxometalate (POM) into poly(4-vinyl pyridine) (P4VP) brushes and the controlled reduction of silver ions, in-situ generating metal nanoparticles in the brushes. P4VP brushes were straightforwardly created by UV-assisted photopolymerization of 4-vinyl pyridine (4VP) on silicon or glass substrates. Phosphotungstic acid (H3PW12O40), one of the most widely used Keggin-type POM was anchored onto these pyridine moieties through electrostatic interaction, leading to the P4VP/POM hybrid brushes. The immobilized POM was further reduced to heteropolyblue, which could be used to generate silver nanoparticles in a controlled fashion. AFM, UV-vis and IR characterization indicate that P4VP brushes not only provide an efficient platform in the controlled preparation of Ag nanoparticles, but also efficiently disperse and stabilize POM, thus preventing the aggregation of the generated Ag nanoparticles.