Hydrogen-Bond-Regulated Platelet Micelles by Crystallization-Driven Self-Assembly and Templated Growth for Poly(ε-Caprolactone) Block Copolymers

Living crystallization-driven self-assembly (CDSA) is a powerful approach to tailor nanoparticles with controlled size and spatially defined compositions from amphiphilic crystalline block copolymers (BCPs). However, a variety of external constraints usually make the successful applications of living CDSA difficult. Herein, such constraints arising from strong hydrogen-bond (H-bond) interactions between unimers that lead to the failure of living CDSA are effectively overcome via reduction of the H-bond strength. In particular, by adding a H-bond disruptor trifluoroethanol (TFE), decreasing the unimer concentration, and reducing the corona segment length, the H-bond strength between unimers could be efficiently alleviated, leading to the formation of uniform two-dimensional (2D) platelets with controlled size and block comicelles with spatially defined corona chemistries. Moreover, by selectively anchoring one-dimensional (1D) seeds on the surface of as-prepared 2D block comicelles through H-bond interaction, the epitaxial growth of a crystalline BCP from immobilized 1D seeds on 2D platelets illustrates competitive growth behavior in a spatially confined environment.

Automated summary

By reducing the hydrogen bond strength, we have overcome the external constraints encountered in living crystallization-driven self-assembly (CDSA), leading to controlled size and spatially defined compositions of nanoparticles.