| 초록 |
The preparation of reverse thermal hydrogels by mixing poly(propylene oxide)-b-poly(ethylene oxide)-b-poly(propylene oxide) α,ω-bisphosphate (PO42--PPO-PEO-PPO-PO42-) and multivalent metal ions is described. In contrast to PPO-PEO-PPO triblock copolymers (reverse Pluronic or Pluronic-R) such as 10R5 ((PPO)9-(PEO)23-(PPO)9, Mw ~ 2000), 17R4 ((PPO)14-(PEO)24-(PPO)14, Mw ~ 2700), and 31R1 ((PPO)26-(PEO)7-(PPO)26, Mw ~ 3300) that do not form hydrogel, the concentrated aqueous solutions of the Pluronic-R, α,ω-bisphosphate showed immediate gelation upon addition of multivalent metal ions such as Ca2+, Cu2+, Zn2+, Mg2+, Fe2+, and Fe3+. Their phase transition was reversible during a repeated heating and cooling cycle. The sol-to-gel transition behaviors depending on the polymer composition, concentration, metal ions, and additives were investigated. |
