A new supramolecular self-assembly approach to construct micelles and reverse micelles was reported.Double-hydrophilic block copolymers poly(ethylene oxide)-b-poly(N-isopropylacrylamide) (PEO-b-PNIPAAm) was synthesized via atom transfer radical polymerization (ATRP) using PEO macroinitiator.Because of the lower critical solution temperature (LCST) phase behavior of PNIPAAm,PEO-b-PNIPAAm block copolymers self-assembled to form PNIPAAm-core micelles at 40 ℃.The PNIPAAm-core micelles were disassembled to unimers when the temperature was decreased to 25 ℃.But the addition of α-cyclodextrins (α-CDs) could induce the formation of PNIPAAm-shell micelles because of the 'channel-type' crystallities induced by PEO/α-CDs polyrotaxanes.The assembly and disassembly procedure of micelles and reverse micelles were investigated by dynamic light scattering (DLS),X-ray diffraction (XRD),1H NMR and transmission electron microscopy (TEM).
