PS-P4VP-PLA triblock copolymer, named as SVA, was synthesized by using the reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerization (ROP). The detailed procedures were described in the Supporting Information (SI). The synthesized triblock copolymer was characterized using gel permeation chromatography (GPC) and proton nuclear magnetic resonance ( 1 H NMR) (Figures and). The molecular weights (Mn) of P4VP, PS-P4VP-OH, and SVA are 5800 g/mol, 33300 g/mol, and 53100 g/mol, respectively. The volume fractions of PS, P4VP, and PLA in SVA are 64%, 8%, and 28%, respectively (Table ). Note that the accurate Mn value of P4VP is calculated based on 1 H NMR result (Figure ).