| 초록 |
A series of poly(acrylic acid-block-N-vinyl amine) (PAA-b-PVAm) amphoteric block copolymers have been synthesized using a combination of activator regenerated by electron transfer atom-transfer radical polymerization (ARGET ATRP) of tert-butyl acrylate and reversible addition-fragmentation chain transfer (RAFT) polymerization of N-vinyl formamide, following by subsequent hydrolysis reaction. Dynamic light scattering (DLS) has been used to study the associative behavior of the copolymers in water as a function of copolymer composition and pH. At the pH range of below and above their isoelectric point (IEP), the block copolymers formed micellar structures with ionized corona of PVAm and PAA, respectively. At around the IEP, strong electrostatic interactions occurred to lead the formation of insoluble complexes between negatively and positively charged blocks. The IEP of the block copolymers was tuned by changing the length of anionic PAA and cationic PVAm blocks. |
