Controllable multicompartment morphologies from cooperative self-assembly of copolymer–copolymer blends

Abstract

Multicompartment nanostructures, such as microcapsules with clearly separated shell and core, are not easily accessible by conventional block copolymer self-assembly. We assess a versatile computational strategy through cooperative assembly of diblock copolymer blends to generate spherical and cylindrical compartmentalized micelles with intricate structures and morphologies. The co-assembly strategy combines the advantages of polymer blending and incompatibility-induced phase separation. Following this strategy, various nanoassemblies of pure AB, binary AB/AC and ternary AB/AC/AD systems such as compartmentalized micelles with sponge-like, Janus, capsule-like and onion-like morphologies can be obtained. The formation and structural adjustment of microcapsule micelles, in which the shell or core can be occupied by either pure or mixed diblock copolymers, were explored. The mechanism involving the separation of shell and core copolymers is attributed to the stretching force differences of copolymers which drive the arrangement of different copolymers in a pathway to minimize the total interfacial energy. Moreover, by adjusting block interactions, an efficient approach is exhibited for regulating the shell or core composition and morphology in microcapsule micelles, such as the transition from the "pure shell/mixed core" morphology to the "mixed shell/pure core" morphology in the AB/AC/AD micelle. This mesoscale simulation study identifies the key factors governing co-assembly of diblock copolymer blends and provides bottom-up insights towards the design and optimization of new a † Electronic Supplementary Information (ESI) available.

Controllable Multigeometry Nanoparticles via Cooperative Assembly of Amphiphilic Diblock Copolymer Blends with Asymmetric Architectures

“…An additional critical aspect for the co-assembly strategy is the incompatibility of different hydrophobic blocks, which determines either attachment or detachment of patches on micelles. 30 The repulsive parameter in the present study (a BC = 45) adopts a moderate repulsion between blocks B and C, thus AC patches are properly adsorbed on micelles. The above effects, including segregation degree, selectivity of solvent and incompatibility of hydrophobic blocks, explain why the assembled nanoparticles phase separate into multi-geometric polymorphs.…”

“…[22][23][24][25][26][27][28][29] For blends of identical block lengths but different block chemistry, we have previously reported a versatile strategy for the preparation of spherical and cylindrical multi-compartment micelles with controllable core and corona structures. 30 By controlling the block length and chemistry, one can design nanostructures with hybrid geometries such as disksphere or disk-cylinder polymeric nanoparticles. 19 This strategy has focused on the cooperative assembly of block copolymer blends with various segregation degrees that lead to different locations and morphologies in multi-geometry nanoparticles.…”

Multicore Assemblies from Three-Component Linear Homo-Copolymer Systems: A Coarse-Grained Modeling Study

“…Copolymer micellization and aggregation in solution has been examined with various computational approaches. These include self-consistent field theory (SCFT) [ 28 , 29 , 30 , 31 , 32 , 33 , 34 ], Monte Carlo simulations [ 35 , 36 , 37 , 38 ], Brownian dynamics [ 39 , 40 , 41 ], dissipative particle dynamics (DPD) simulations [ 42 , 43 , 44 , 45 , 46 ], and at more limited length and time scales, coarse-grained and atomistic molecular dynamics simulations [ 47 , 48 , 49 , 50 ]. As multicore self-assembly has both high practical significance and interest from theory and computational points of view, different theoretical and computational works have been devoted to multicore aggregation.…”

Effect of Ultrasonication on Self-Assembled Nanostructures Formed by Amphiphilic Positive-Charged Copolymers and Negative-Charged Drug

“…Core–shell structures composed of a water-soluble shell and a discriminative hydrophobic core are novel, unusual morphologies for application in a variety of fields, including medicine, pharmacology, and biotechnology. , So far, the preparation and control of the formation of core–shell structure systems have been shown to follow the coassembly strategies or environmental stimuli-responsive copolymers through an intermediary of subunits preassembling. ,, Step-growth polymerization is shown to be the significant force to develop core–shell-like nanoparticles in almost all reports; however, it does not take payload into account. Moreover, even though core–shell structures are based on synthetic thermal block amphiphilic polymers, these micelles after micellar solubilization of drug are in random morphologies leading to uncontrolled size distribution, which are not precisely predictable. , …”