Fabrication of unimolecular micelles with uniform sizes and well-controlled structure is currently a big challenge. Herein, we report an easy-to-handle protocol for the preparation of nearly monodisperse unimolecular micelles via atom transfer radical polymerization (ATRP) mediated by chloroacetylated initiator and chloride catalyst (Cl-ATRP). In contrast to Br-ATRP employing bromoacetylated initiator and CuBr as catalyst, Cl-ATRP can significantly suppress chain coupling during the synthesis of unimolecular micelles and result in well-defined polymers with low molar mass dispersity (Ð < 1.10) even at high monomer conversions (e.g. ~80%) and extended reaction times. In addition, effort was made to inhibit the formation of linear polymer side products (typical for ATRP of unimolecular micelles). With the optimized protocol, no linear polymer could be detected by size exclusion chromatography (SEC). The obtained nearly monodisperse unimolecular micelles may find application in, e.g. cargo delivery and bio-imaging as also demonstrated in this report. Considering its superior control in ATRP, the easily utilized Cl-ATRP protocol could be extended to the ATRP of, e.g. brush polymers and comb-like polymers where high local radical concentration needs to be avoided.

制备具有均匀尺寸和良好控制结构的单分子胶束是目前的一大挑战。在此，我们报告了一种易于操作的协议，用于通过由氯乙酰化引发剂和氯化物催化剂 (Cl-ATRP) 介导的原子转移自由基聚合 (ATRP)制备几乎单分散的单分子胶束。与使用溴乙酰化引发剂和 CuBr 作为催化剂的 Br-ATRP 相比，Cl-ATRP 可以在单分子胶束的合成过程中显着抑制链偶联，并且即使在高单体转化率下也能产生具有低摩尔质量分散性 ( Ð < 1.10)的明确聚合物（例如~80%) 和延长反应时间。此外，还努力抑制线性聚合物副产物的形成（典型用于单分子胶束的 ATRP）。使用优化的方案，尺寸排阻色谱 (SEC) 无法检测到线性聚合物。获得的几乎单分散的单分子胶束可以应用于例如货物输送和生物成像，如本报告中也证明的那样。考虑到其在ATRP出色的控制，易使用的CL-ATRP协议可以扩展到的ATRP，例如刷状聚合物和梳状，其中要避免的高的局部自由基浓度需要的聚合物。