Formation of silver nanoparticles created in situ in an amphiphilic block copolymer film

In this work, silver nanoparticles were synthesized with an amphiphilic diblock copolymer, poly-styrene-block-poly(1-vinyl-2-pyrrolidone) (PS-b-PVP), as a template film. First, microphase-separated amphiphilic PS-b-PVP (70 : 30 wt %) was synthesized through atom transfer radical polymerization. The self-assembled block copolymer film was used to template the growth of silver nano-particles by the introduction of a silver trifluoromethanesulfonate precursor and an ultraviolet irradiation process. The in situ formation of silver nanoparticles with an average size of 4-6 nm within the block copolymer template film was confirmed with transmission electron microscopy, ultraviolet-visible spectroscopy, and wide-angle X-ray scattering. Fourier transform infrared spectroscopy also demonstrated the selective incorporation and in situ formation of silver nanoparticles within the hydrophilic poly(lvinyl-2-pyrrolidone) domains, which were mostly due to the stronger interaction strength of the silver with the carbonyl oxygens of poly(1-vinyl-2-pyrrolidone) in the block copolymer. This work provides a simple route for the in situ synthesis of silver nanoparticles within a polymer film.