Crystal-driven Living Self-asembly Of Poly (N-octylglycine) Block Polymers In Methanol

The formation of complex hierarchical structures with precise morphological by hierarchical self-assembly is ubiquitous in nature,and plays an essential role in the regulation of biological functions.Inspired by the multi-scale hierarchical structure in biology,many methods have been explored to prepare hierarchical nanostructures with precise morphology.Polypeptoids are a kind of biomaterial similar to polypeptides,and have broad application prospects in many fields such as biomedicine and nanotechnology.In this paper,a kind of diblock polypeptoid poly(ethylene glycol)-block-poly(N-octylglycine)with good crystallization performance is reported to prepare an exquisite supramolecular planar nanobrush-like structure by hierarchical self-assembly.The polymer brush composes of two distinct packing patterns,including the core spine in the middle and fibers on both sides.We demonstrate that the superstructures result from the temperature-controlled hierarchical self-assembly of pre-assembled spherical micelle motifs,and propose two types of crystallization-driven self-assembly behaviors: "self-seeding" and "seeded growth".The nanobrush-like structure has a similar mode of living polymerization driven by crystallization so that it can be further assembled laterally after the subsequent addition of the polymer.This assembly mechanism is different from the previously reported crystallization-driven method.It is not directly grown from the added crystallizable block copolymer along the seed crystal,and more akin to protein crystallization.The sphere is formed first and then the sphere is fused to the original some nanobrush-like are on the side.Due to the tunability of the structure of the plypeptoids,systematic studies on the effects of changing the side chain group structure,block degree of polymerization ratio,and molecular weight on the assembly structure of the polymer,In addition,the morphology of the nanobrush-like structure can also be adjusted by adjusting different temperatures,concentrations,and cooling rates,and then the ratio of the added crystallizable block copolymer to the nanobrush-like seed crystal seed can be further prepared to be uniform and controllable.In view of the high degree of controllability of the chemical structure of the polypeptoid and its excellent biocompatibility,it has great application value in the fields of self-assembly nanomaterials and biomedicine.