Fusion Growth of Two-Dimensional Disklike Micelles via Liquid-Crystallization-Driven Self-Assembly

Abstract

Liquid-crystallization-driven self-assembly (LCDSA) is an emerging strategy for constructing nanoassemblies, such as 1D cylindrical micelles with LC-like micellar cores. However, it is still unknown whether LCDSA can be applied to higherdimensional self-assembly. Herein, we realize the growth of two-dimensional (2D) disklike micelles via LCDSA and reveal its mechanism. Disklike seeds are constructed through the self-assembly of poly(γ-benzyl L-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) block copolymers in solution. In the micellar core, the PBLG rod blocks take a smectic LC-like packing manner. After PBLG-b-PEG unimers are added into the seed solution, they first self-assemble into small aggregates. The aggregates then fuse with the seed edges to achieve the epitaxial growth of the disklike micelles. Brownian dynamic simulations reveal that the rod blocks in the small aggregates rearrange themselves to match the LC-like structure of the seed core in the growth process. The contour area of the disklike micelles is dependent on the unimer-to-seed ratio, and the 2D growth kinetics can be well controlled to construct concentric disklike micelles. The observed growth behavior of disklike micelles extends the LCDSA from 1D to 2D and can address the challenge of the precise manipulation of 2D nanostructures.

Mesoporous Phenolic/POSS Hybrids Induced by Microphase Separation Arising from Competitive Hydrogen Bonding Interactions

“…The self-assembly of linear diblock copolymers in the bulk state, forming body-centered cubic (BCC), hexagonal-packing cylinder (HEX), double-gyroid (DG), and lamellae (LAM) structures, mediated by the interaction parameter (χ), volume fraction ( f ), and molecular weight ( N ), is being investigated widely because of their potential applications in nanopatterns, nanocomposites, drug delivery, and electronic and photonic devices. − Blending diblock copolymers with homopolymers, copolymers, nanoparticles, and organic–inorganic hybrids to vary the volume fractions and interaction parameters, mediated by hydrogen-bonding interactions, is another simple approach toward fabricating various self-assembled structures. − Recently, Frank–Kasper (FK) phases, including A15, σ, C14, and C15 phases, have also been observed in the phase diagrams of diblock copolymers through both experimental studies and theoretical predictions. − …”

2D Liquid-Crystallization-Driven Self-Assembly of Rod–Coil Block Copolymers: Living Growth and Self-Similarity

“…For example, when the interaction strength and the copolymer concentration are in the red region of Figure 1a, the added copolymers first assemble into small aggregates, and then these aggregates fuse with disk seeds, resulting in the growth of disklike micelles. 16 Figure 2b−e shows the growth process of disklike micelles. There was no self-aggregation of added unimers, and the preassembled disklike seeds grew through individual incorporation of the newly added copolymers.…”

“…The 2D nanostructure is a fascinating morphology existing in nature, such as red blood cells and chloroplast thylakoids. , The 2D nanostructure has attracted extensive attention in various fields; for example, as a stabilizer for water-in-water Pickering emulsions, such stabilization benefits from high surface area and controllable surface properties of 2D nanostructures. − 2D controllable polymeric assemblies have been constructed by the living growth of micelles. For example, Winnik and Manners et al prepared 2D structures with controllable size via crystallization-driven self-assembly (CDSA) of crystalline block copolymers. − Recently, various 2D nanostructures, including disklike, − lamella, ,,− nanosheets, − patchy and hollow platelet micelles, − have been obtained; however, their 2D living growth kinetics have rarely been reported. − …”

“…If the conditions are not in such a metastable region, the growth behaviors are different. For example, when the interaction strength and the copolymer concentration are in the red region of Figure a, the added copolymers first assemble into small aggregates, and then these aggregates fuse with disk seeds, resulting in the growth of disklike micelles …”

“…Our theoretical findings can also provide an insight into the 2D living growth of micelles in crystalline copolymer systems. In the experiments of LCDSA systems, the interaction strength of rod blocks can be regulated by solvent composition and temperature . Therefore, multistep living growth with self-similarity kinetics can be realized by choosing the appropriate solvent composition and experimental temperature.…”