Experimental Block copolymer synthesis: Polystyrene-b-poly(N,N-dimethyl acrylamide), PS 365 -PDMA 125 (the subscripts denote the repeating unit numbers of the corresponding blocks), was synthesized via sequence reversible addition-fragmentation chain transfer (RAFT) polymerizations. The molecular weight of the polymer is 54,800 g/mol and the polydispersity is 1.16. Preparation of micelle solutions: 5.0 mg of PS 365 -PDMA 125 was dissolved in 0.5 ml of tetrahydrofuran (THF) and then the solution

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... was quickly injected via a syringe into 9.5 mL of isopropanol alcohol (IPA) to form micelles, or the polymers were directly mixed with IPA at 50 o C for 0.5 hour before cooling to room temperature. Sonication (10 min each time for 2-5 times) was also used to assist the dispersion of the copolymer. The hydrophobic PS chains collapsed to form micellar cores and the hydrophilic PDMA chains stretched into IPA to form micellar coronas.