Study for Coordination Power between Poly(2-vinylpyridine) and Poly(4-vinylpyridine) by Phase Behavior of Poly(2-vinyl pyridine)-block-poly(4-vinyl pyridine) copolymer with Gold Nanoparticles.

For study the coordination power for metal precursor between Poly(2-vinylpyridine) and Poly(4-vinylpyridine), We studied, for the first time, the phase behavior of poly(2-vinyl pyridine)-block-poly(4-vinyl pyridine) copolymer (P24VP) with gold nanoparticles via rheometry, small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), TEM and S-TEM. Although both blocks of P24VP exhibit attractive interaction to gold nanoparticles, we found it shows the unusual phase behavior as increasing the amount of gold nanoparticles. Neat P24VPs with lamellar or cylinder microdomains show fully ordered phases over the entire experimental temperatures up to 300oC.
At first, the order-to-disorder transition temperature (TODT) of P24VP with gold nanoparticles was found, and decreased with more gold nanoparticles. As increasing the amount of gold nanoparticles, it increased, but again decreased until the amount of that reached the full mole ratio to P24VP. It is due to the competitive interaction between P2VP and P4VP to gold precursors. To prove this unusual behavior, we compare two reference block copolymers PS-b-P4VP and PS-b-P2VP. Finally, we cehcked the particle location by TEM and S-TEM.