Two-dimensional (2D) quasi-living crystallization-driven self-assembly of polyethylene-b-hyperbranched polyglycidol diblock copolymers in solution†

Abstract

This paper presents a systematic investigation of the crystalline nucleation, micellization, two-dimensional (2D) growth of polyethylene-b-hyperbranched polyglycidol (PE-b-hbPG) copolymers in solutions during cooling and isothermal crystallization. As a result, lozenge-shaped monolayer or multilayer lamellar crystals were prepared by optimizing the “self-nucleation” conditions. The effect of crystallization temperatures (T_c), critical micelle temperature (CMT), selective solvents, and the topology of block copolymers (BCPs) on the growth of 2D lozenge-shaped crystals is extensively explored using TEM, AFM and in situ DLS techniques. The results demonstrate that the formation of a perfect lozenge-shaped monolayer crystal is contingent upon the relationship between CMT and T_c of the BCPs (CMT < T_c), as well as the isothermal crystallization temperature T_iso (CMT < T_iso < T_c). This significant finding provides a feasibility programme for the preparation of 2D lamellar crystals using the “self-nucleation” approach from an alternative viewpoint of the corona topology.