Synthesis and induced micellization of Pd-containing polystyrene-block-poly-m-vinyltriphenylphosphine diblock copolymers

A novel type of chelating block copolymer, polystyrene-block-poly-m-vinyler iphenylphosphine (PS-b-PPH), was reacted with (CH3CN)(2)PdCl2 or (PPh3)(2)P dCl2, and the products were examined with FTIR, P-31 NMR spectroscopy,and e lemental analysis, The complexation of triphenylphosphine groups of these p olymers with palladium compounds induces micellization in the system, and n o polymer gels were formed. The morphology of the Pd-containing diblock cop olymer micelles was studied with transmission electron microscopy (TEM). Th e size and kind of micellar aggregates depends strongly on the molecular we igh of diblock copolymer, its composition, and metal compound type. Block c opolymer-stabilized Pd nanoparticles were prepared by reduction of Pd-conta ining PS-b-PPH with N2H4.H2O, LiB-(C2H5)(3)H, and LiAlH4 and analyzed by TE M, X-ray photoelectron spectroscopy, and wide-angle X-ray scattering techni ques. It is found that the morphology of nanoparticles is controlled by the way of reduction and by the nature of the polymeric aggregates.