Constructing and decoding tree-ring-like surface patterns on self-assembled polymer platelets

Abstract

Precise control of surface patterns in assembled nanostructures remains a significant challenge in materials science. Here, we introduce a scalable bottom-up strategy utilizing living crystallization-driven self-assembly (CDSA) to fabricate tunable 3D surface patterns on polymer platelets. Inspired by biological growth increments, our approach leverages temperature-regulated, time-dependent crystallization to direct nanoscale organization, mimicking how nature constructs layered architectures. By exploiting polymer systems with temperature-dependent crystallization kinetics, we achieved diverse morphologies—including layered, concave, and convex features through controlled co-assembly and kinetic self-sorting. Temporal-thermal modulation was implemented in a continuous flow reactor, where precisely programmed residence times and temperature profiles enabled spatially resolved material deposition and growth history encoded in tree-ring-like patterns - control that is challenging or impossible to achieve using conventional batch methods. These features achieved lateral and vertical resolutions of ~73 nm and ~2 nm, respectively, allowing quantitative determination of directional crystallization rates (22.8 nm/s along the long axis and 13.4 nm/s along the short axis). Furthermore, modulating the number of layers provided a practical means to tune surface wettability. Our bioinspired design framework bridges synthetic self-assembly and natural structural logic, expanding opportunities for programmable materials in nanotechnology and functional systems. Control of surface patterns in assembled nanostructures is desirable, but challenging to achieve. Here, the authors report the development of a flow-based crystallisation-driven self-assembly method for the preparation of polymer platelets with controlled 3D surface patterns.