文摘
Amphiphilic block copolymers such as polystyrene-block-poly(acrylic acid) (PSPAA) give micelles that are known to undergo sphere-to-cylinder shape transformation. Exploiting this polymer property, core鈥搒hell nanoparticles coated in PSPAA can be 鈥減olymerized鈥?into long chains following the chain-growth polymerization mode. This method is now extended to include a variety of different nanoparticles. A case study on the assembly process was carried out to understand the influence of the PAA block length, the surface ligand, and the size and morphology of the monomer nanoparticles. Shortening the PAA block promotes the reorganization of the amphiphilic copolymer in the micelles, which is essential for assembling large Au nanoparticles. Small Au nanoparticles can be directly 鈥渃opolymerized鈥?with empty PSPAA micelles into chains. The reaction time, acid quantity, and the [Au nanoparticles]/[PSPAA micelles] concentration ratio played important roles in controlling the sphere鈥揷ylinder鈥搗esicle conversion of the PSPAA micelles, giving rise to different kinds of random 鈥渃opolymers鈥? With this knowledge, a general method is then developed to synthesize homo, random, and block 鈥渃opolymers鈥? where the basic units include small Au nanoparticles (d = 16 nm), large Au nanoparticles (d = 32 nm), Au nanorods, Te nanowires, and carbon nanotubes. Given the lack of means for assembling nanoparticles, advancing synthetic capabilities is of crucial importance. Our work provides convenient routes for combining nanoparticles into long-chain structures, facilitating rational design of complex nanostructures in the future.
Keywords:
polymerization of nanoparticles; assembly; chain growth polymerization; PSPAA micelle; vesicle