The hybrid particle–field method is extended to investigate self-assembly and percolating behavior of nanocomposites containing block copolymers and nanoparticles. The self-assembled nanostructures serve as templates to guide organization and distribution of nanoparticles. The percolation threshold of nanoparticles in the host of block copolymers is discussed in terms of composition of block copolymers, radius, and aspect ratio of nanoparticles. The simulated results demonstrate that the block copolymers have a synergistic or antagonistic effect on emergence of percolating network of nanoparticles, depending on the copolymer composition. There exists an optimal value of copolymer composition for lowering the percolation threshold of nanoparticles. In addition, regulating the geometrical shape of nanoparticles further lowers the percolation threshold of nanoparticles dispersed in the block copolymers. These simulated results provide useful guidelines for designing high-performance composite materials with light weight.

AbstractConstructing polymeric toroids with a uniform, tunable size is challenging. Reported herein is the formation of uniform toroids from poly(γ-benzyl-l-glutamate)-graft-poly(ethylene glycol) (PBLG-g-PEG) graft copolymers by a two-step self-assembly process. In the first step, uniform rodlike micelles are prepared by dialyzing the polymer dissolved in tetrahydrofuran (THF)/N,N′-dimethylformamide (DMF) against water. With the addition of THF in the second step, the rodlike micelles curve and then close end-to-end to form uniform toroids, which resemble a cyclization reaction.

AbstractConstructing polymeric toroids with a uniform, tunable size is challenging. Reported herein is the formation of uniform toroids from poly(γ-benzyl-l-glutamate)-graft-poly(ethylene glycol) (PBLG-g-PEG) graft copolymers by a two-step self-assembly process. In the first step, uniform rodlike micelles are prepared by dialyzing the polymer dissolved in tetrahydrofuran (THF)/N,N′-dimethylformamide (DMF) against water. With the addition of THF in the second step, the rodlike micelles curve and then close end-to-end to form uniform toroids, which resemble a cyclization reaction.

Self-assembly of copolymers in solution is a promising way to prepare novel materials. An accurate control over the self-assembly of copolymers in solution requires a profound understanding about the related thermodynamic rules and kinetic mechanisms. Theoretical modeling and simulation play an increasingly important role in characterizing the structure details and the formation process of polymer assemblies. In this review, we first introduce theoretical modeling and simulation methods that have been applied to investigate the self-assembly of copolymers in solution, including particle-based methods, field-theoretical methods and hybrid modeling methods Then, the application of these methods for the self-assembly of linear block copolymers in solution is highlighted, including the thermodynamic rules and kinetic mechanisms underlying the formation of self-assembled structures. Furthermore, the simulation works of the self-assembly of branched copolymer systems, including graft copolymers, star-like copolymers, dendritic copolymers and bottle-brush copolymers, are addressed. In addition to the one-component polymer systems, simulation investigations of polymer mixture systems are discussed, both the polymer/polymer systems and polymer/nanoparticle systems are considered. Finally, perspectives on the theoretical modeling and simulation in the field of self-assembly of copolymers in solution are presented in the section of concluding remarks and outlook.

Spherical nanostructures with striped patterns on the surfaces resembling the essential structures of natural virus particles were constructed through a two-step self-assembly approach of polystyrene-b-oligo(acrylic acid) (PS-b-oligo-AA) and poly(γ-benzyl L-glutamate)-b-poly(ethylene glycol) (PBLG-b-PEG) copolymer mixtures in solution. On the basis of difference in hydrophilicity and self-assembly properties of the two copolymers, the two-step self-assembly process is realized. It was found that PS-b-oligo-AA copolymers formed spherical aggregates by adding a certain amount of water into polymer solutions in the first step. In the second step, two polymer solutions were mixed and water was further added, inducing the self-assembly of PBLG-b-PEG on the surfaces of PS-b-oligo-AA spheres to form striped patterns. In-depth study was conducted for the indispensable defects of striped patterns which are dislocations and +1/2 disclinations. The influencing factors such as the mixing ratio of two copolymers and the added water content in the first step on the morphology and defects of the striped patterns were investigated. This work not only presents an idea to interpret mechanism of the cooperative self-assembly behavior, but also provides an effective approach to construct virus-like particles and other complex structures with controllable morphology.Download high-res image (127KB)Download full-size imageSpherical core-shell virus-like particles with strip-pattern surface are fabricated through a two-step self-assembly of two block copolymers.

P(FpC3P) (Fp: CpFe(CO)2; C3P: propyl diphenyl phosphine) has a helical backbone, resulting from piano stool metal coordination geometry, which is rigid with intramolecular aromatic interaction of the phenyl groups. The macromolecule is hydrophobic, but the polarized CO groups can interact with water for aqueous self-assembly. The stiffness of P(FpC3P), which is adjustable by temperature, is an important factor influencing the morphologies of kinetically trapped assemblies. P(FpC3P)7 self-assembles in DMSO/water (10/90 by volume) into lamellae at 25 °C, vesicles at 40 °C and irregular aggregates at higher temperatures (60 and 70 °C). The colloidal stability decreases in the order of lamellae, vesicles and irregular aggregates. Dissipative particle dynamics (DPD) simulation reveals the same temperature-dependent self-assembled morphologies with an interior of hydrophobic aromatic groups covered with the metal coordination units. The rigid backbone at 25 °C accounts for the formation of the layered morphology, while the reduced rigidity of the same P(FpC3P)7 at 40 °C curves up the lamellae into vesicles. At a higher temperature (60 or 70 °C), P(FpC3P)7 behaves as a random coil without obvious amphiphilic segregation, resulting in irregular aggregates. The stiffness is, therefore, a crucial factor for the aqueous assembly of macromolecules without obvious amphiphilic segregation, which is reminiscent of the solution behavior observed for many hydrophobic biological macromolecules such as proteins.

Nanoparticles can co-assemble with amphiphilic block copolymers (ABPs) in solution to generate nanoaggregates with unique properties, yet the mechanism of such a co-assembly behaviour for Janus nanoparticles (JPs) and ABPs remains unclear. Here, the self-assembly behaviour of JP/ABP mixtures in dilute solution was studied via theoretical simulations. Two kinds of ABPs with different volume fractions fA of hydrophilic blocks were considered: one is symmetric copolymers with fA = 0.5, and the other is asymmetric ABPs with fA = 0.3. In the first case, mixtures of spheres and rods, connected networks and vesicles were formed sequentially as the volume fraction cJP of nanoparticles increases. In the second case, vesicles were constantly formed. For both cases, at lower cJP values, the nanoparticles were located at the core–corona interfaces. By contrast, at higher particle loadings, a large number of particles were involved in clusters embedded in the vesicle walls. Based on the simulation results, a morphological diagram in the space of cJP and fA was constructed to indicate the stability regions of different nanostructures. Specifically, it was found that the vesicles formed by JPs and ABPs with short hydrophilic blocks are stimuli-responsive. By changing the interaction parameters between hydrophobic blocks, controllable pores in the vesicle walls could be created. Our findings not only provide insights into the co-assembly behaviour of Janus nanoparticles and amphiphilic block copolymers in solution, but also offer a novel strategy to prepare nanoreactors with permeable membranes.

The fabrication of desired structures is one of the most urgent topics in current research on porous polymer films. Herein, directional photomanipulation in conjunction with breath figure processing has been demonstrated for the preparation of porous polymeric films with finely tunable pore shape and size. Because of the photoinduced directional mass migration of azobenzene units upon vertical incident linearly polarized light (LPL) irradiation, round pores on honeycomb films can be reshaped into multifarious shapes including rectangle, rhombus, dumbbell, line, and so forth. In addition, slantwise LPL irradiation produces unique asymmetrical structure inside the pores oriented along the polarized direction. On the other hand, circularly polarized light (CPL) irradiation affords manipulation of the wall thickness without changing the pore shape. This versatile directional photomanipulation method can be implemented to large-area and high-throughput reshaping processes, which paves the way to a number of promising applications such as a flexible etching mask for patterning.Keywords: azobenzene; block copolymers; photomanipulation; porous films; self-assembly;

Self-consistent field theory with a dynamic extension is exploited to investigate the kinetics of the lamellar formation of symmetric block copolymers under the direction of external fields. In particular, three types of directed self-assembly methods – a permanent field for chemo-epitaxy, a dynamic field for zone annealing and an integrated permanent/dynamic field – are examined. For the chemo-epitaxy involving sparsely prepatterned substrates or zone annealing, the block copolymers generally develop into polycrystalline nanostructures with multiple orientations due to the lack of strong driving forces for eliminating the long-lived imperfections in a limited time. As the integrated chemo-epitaxy and zone annealing method is applied to the block copolymer systems, single-crystalline nanostructures with precisely registered orientations are achieved in a short annealing time owing to the mutual acceleration of defect annihilations, which cannot be produced by the conventional techniques alone. Furthermore, the integrated method allows the rapid fabrication of well-ordered nanostructures on the extremely sparse prepatterned substrates. Our theoretical work may serve to rationalize the faster modern nanolithographic fabrication of smaller microelectronic components using lower-spatial-frequency templates.

The ability to design and fabricate highly ordered superstructures from nanoscale particles remains a major scientific and technological challenge. Patchy nanoparticles have recently emerged as a novel class of building units to construct functional materials. Using simulations of coarse-grained molecular dynamics, we propose a simple approach to achieve soft nanoparticles with a self-patchiness nature through self-assembly of tethered copolymers with a sequence of inner solvophilic and outer solvophobic blocks. As building units, the patch-like nanoparticles are directed to further assemble into a rich variety of highly ordered superstructures via condensation–coalescence mechanisms. The growth kinetics of the superstructures obeys the kinetic model of the step-growth polymerization process. Our simulations also demonstrate that the intermediate patch-like nanoparticles and the final assembled superstructures can be rationally tuned by changing the number and the composition of the tethered copolymer chains. This strategy of copolymer functionalization conceptually enables the design and fabrication of highly ordered superstructures of nanoparticle ensembles with new horizons for promising applications in soft nanotechnology and biotechnology.

In this work, the structures and topological defects of striped patterns self-assembled from rod–coil diblock copolymers confined on spherical substrates were examined using dissipative particle dynamics simulations. The stripes were formed by orderly packed rod blocks that were stabilized by coil blocks in solvents. Three types of disclinations with charges of +1, +1/2, and −1/2 and dislocations were observed in the striped patterns. The sum of the disclination charges was always +2, which is consistent with the Poincaré–Hopf theorem. Two categories of local defect stripe patterns were observed, namely, spiral-like and ring-like. The structures and surface densities of the defects were found to depend on various parameters, including the rigidities of the rod blocks, the radii of the spheres and the hydrophobicities of the rod blocks. The predictions were compared with our previous experimental observations and agreement was found. This work provides a method for producing striped patterns on curved substrates and can serve as a theoretical support for preparing nanoparticles with complex surface structures.

Mineralization behaviour of CaCO3 in the presence of polypeptide vesicles self-assembled from poly(L-glutamic acid)-block-poly(propylene oxide)-block-poly(L-glutamic acid) (PLGA-b-PPO-b-PLGA) triblock copolymers was studied. Under the mediation of PLGA-b-PPO-b-PLGA vesicles, CaCO3 fibre clusters were obtained. The structure of fibres could be regulated by the mineralization temperature, copolymer composition, copolymer concentration, and Ca2+ concentration. The investigation of the fibre growth process suggested a solution–precursor–solid mechanism via transient amorphous precursors. Since the polypeptide vesicles could serve as both the modifier and template for the formation of amorphous precursors, the properties of amorphous precursors were affected by the vesicular structure. The variation in the fibre structure was ascribed to the different aggregation and transformation behaviours of amorphous particles. These findings can provide useful information for the design of novel inorganic materials with fibrous structures and enrich our existing knowledge of the crystallization process from the amorphous phase.

Copolymer systems can self-assemble into diverse nanostructures, which have gained significant attention because of their diverse and expanding range of practical applications, such as in microelectronic materials, optics and optoelectronics. Theoretical simulations offer a useful approach for the investigation of the evolution and formation of nanostructures and for determining their structure–property relationships. In this article, we highlight notable recent advances in simulation investigations of the nanostructures formed by the self-assembly of linear and nonlinear copolymers. We then focus on the theoretical simulations of the structure–property relationships of copolymer systems. The relationship between the nanostructures and their functional properties, including photovoltaic, optical and mechanical properties, is emphasized. Finally, we suggest directions for the further development of nanostructures formed by copolymer systems, especially regarding theoretical simulations of these systems. In addition, taking full advantage of the nanostructural feature, promising applications are suggested.

It is an extremely challenging task to construct three-dimensional (3D) well-ordered superstructures with controllable morphologies and predictable internal components. Using computational modeling, we conceive and demonstrate a novel class of templates with topographically and chemically patterned surfaces for directing the self-assembly of symmetric block copolymers. Large-cell simulations of self-consistent field theory corroborate that 3D sophisticated structures of vertical lamellae with different in-plane orientations are achieved and the placements of grain interfaces are regulated by post height and commensurability conditions. Notably, non-orthogonally crossed structures are created by simply modulating the periodicities of post arrays. This work may provide a novel route for experimentalists to fabricate 3D long-range ordered structures with tunable local characteristics.

The synthesis of multicomponent superhelices with determined chirality has been realized. By adding water to polymer solution in organic solvents (tetrahydrofuran/N,N′-dimethylformamide, THF/DMF), poly(γ-benzyl l-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) are able to pack orderly around the surface of PBLG homopolymer bundles with designed helical structures, e.g., right-handed and left-handed, depending on THF/DMF ratio and temperature. A systematic investigation leads to the construction of a temperature–organic solvent composition phase diagram. Before the organic solvents were totally removed, the chirality of the assemblies can be reversibly switched using temperature stimulus. This temperature-stimulated chirality transition of polypeptide superhelices is unprecedented. Circular dichroism (CD) experiments indicated that the packing mode of pending phenyl groups from PBLG chain is responsible for the determination of the helical morphologies.

•Triblock copolymers with various rod blocks are designed for hierarchical structures.•Hierarchical liquid crystal exhibits diverse ordering degrees and tilt angles.•Smectic C transforms into arrowhead-like smectic C via changing copolymer symmetry.Brownian dynamics simulations are performed to investigate self-assembly behavior of rod-coil-rod triblock copolymers that contain two types of rod blocks. These rod-coil-rod triblock copolymers are capable of self-assembling into liquid crystalline (LC) structures with hierarchy. The morphologies of the hierarchical LC structures can be controlled by temperature, symmetry of LC blocks, and block length. As the temperature decreases, a transition from isotropic lamellae to smectic C lamellae is observed, accompanied by an increase in orientational ordering and tilt angle of rod blocks. For the hierarchical lamellae-in-lamella structures formed by symmetric block copolymers, there are two LC phases with nearly identical ordering and tilt angle for two rod blocks. While for the lamellae-in-lamellae formed by asymmetric block copolymers, the two LC phases exhibit two different length scales with diverse ordering degrees and tilt angles. By adjusting the lengths of coil and rod blocks, the stability regions of the structures are mapped out in space of the block length versus the temperature. The findings in the present work could provide useful information for understanding the self-assembly behavior of rod-coil-rod triblock copolymers and designing hierarchical liquid crystalline structures.

Cooperative self-assembly behavior of rod–coil–rod poly(γ-benzyl-l-glutamate)-block-poly(ethylene glycol)-block-poly(γ-benzyl-l-glutamate) (PBLG-b-PEG-b-PBLG) amphiphilic triblock copolymers and hydrophobic gold nanoparticles (AuNPs) was investigated by both experiments and dissipative particle dynamics (DPD) simulations. It was discovered that pure PBLG-b-PEG-b-PBLG copolymers self-assemble into ellipse-like aggregates, and the morphology transforms into vesicles as AuNPs are introduced. When the hydrophobicity of AuNPs is close to that of the copolymers, AuNPs are homogeneously distributed in the vesicle wall. While for the AuNPs with higher hydrophobicity, they are embedded in the vesicle wall as clusters. In addition to the experimental observations, DPD simulations were performed on the self-assembly behavior of triblock copolymer/nanoparticle mixtures. Simulations well reproduced the morphology transition observed in the experiments and provided additional information such as chain packing mode in aggregates. It is deduced that the main reason for the ellipse-to-vesicle transition of the aggregates is attributed to the breakage of ordered and dense packing of PBLG rods in the aggregate core by encapsulating AuNPs. This study deepens our understanding of the self-assembly behavior of rod–coil copolymer/nanoparticle mixtures and provides strategy for designing hybrid polypeptide nanostructures.

The microphase separation of side chain liquid crystalline (SCLC) block copolymers was studied using dissipative particle dynamics (DPD) simulations. The block copolymer monomer consists of flexible A segments and flexible B segments grafted by rigid C side chains, where the A, B and C blocks are incompatible with each other. The phase structures of the SCLC copolymers were found to be controlled by A and C block lengths and the graft number. Various mesophases, such as spheres, cylinders, gyroids, and lamellae, were obtained. Phase stability regions in the space of C block length and A block length (or graft number and A block length) were constructed. The packing ordering of C side chains was also studied, and discovered to increase as the temperature decreases or the rigid C side chains increase. In addition, the results of the SCLC copolymers were compared with those of flexible copolymers and available experimental observations. The simulation results in the present work provide useful information for future investigations on SCLC copolymers.

•Polymers owning optical properties and their self-assembly behaviors are presented.•Self-assembly of amphiphilic copolymers generates unique optical properties.•Self-assemblies with optical properties are promising in biomedical applications.As a promising technique for preparing polymeric materials with novel structures and properties, self-assembly is gaining increasing attentions. The applications of self-assemblies raise the claim of full expression of inherent functions and adequate stimuli-responsive features. Light is an excellent media for the realization of inherent functions, in favor of the communication with external environments. The aggregates self-assembled from polymers with optical functions can bring multifarious optical properties and promising applications. In the assemblies, the emission and fluorescence properties of polymers are dependent on both the aggregation type of the polymers and the aggregation-induced effects including planarization and specific intermolecular interactions. The aggregation-induced optical properties are influenced by external stimuli including pH and temperature, which confer various applications, such as in the areas of bioimaging and optical sensor. When photo-responsive groups with photochromism, photo-crosslink or photo-degradation properties are incorporated into polymers, self-assemblies are able to change their shape and inner structure under light irradiation. Such light triggered property is suitable in application for controllable release of loaded species from assemblies. We also discuss the challenges and developing directions regarding the studies and applications of self-assemblies from polymers with optical properties.

•Self-consistent field theory with Yukawa potentials is developed.•Parallel-to-perpendicular lamellae-in-lamellae transition is predicted.•Observation of tetragonal-to-hexagonal cylinder transition is successfully explained.We extended self-consistent field theory to study the phase behavior of supramolecular blends of diblock copolymers with hydrogen-bonding interactions. The hydrogen-bonding interactions are described by Yukawa potentials. The hydrogen-bonding donors and acceptors were modeled as two blocks smeared with opposite screened charges. Hierarchical microstructures such as parallel and perpendicular lamellae-in-lamellae were observed. The appearance of parallel/perpendicular lamellae-in-lamellae depends on the strength of hydrogen-bonding interactions related to the density of hydrogen bonds and the characteristic lengths of the Yukawa potentials. Phase diagrams were correspondingly mapped out, and the domain size, interfacial width and free energies were examined to gain insight into the phase transitions. It was also found that the revealed mechanism can account for some experimental phenomena that are not well explained yet. The present method can be readily further extended to more complicated supramolecular systems with hydrogen-bonding interactions.A self-consistent field theory was developed to study the phase behavior of supramolecular blends of diblock copolymers with hydrogen-bonding interactions, and the phase transitions such as parallel-to-perpendicular lamellae-in-lamellae transition were predicted.

•Large-cell simulations of directed self-assembly of block copolymers.•Independent manipulation of cylinder orientation in various layers.•Design strategies for three-dimensional device-oriented superstructures.•Formation range of vertical interconnections in three-dimensional structures.Directed self-assembly of block copolymers offers a novel paradigm for building up three-dimensional (3D) device-oriented nanostructures towards deep sub-100-nm resolution. To clearly unveil the 3D patterns with long-range order, we herein utilize computer simulations to explore the directed self-assembly behaviors of cylindrical-forming block copolymer films in topographical templates. Unlike the 3D architectures in the bulk, the cylinder orientations in various layers of 3D ordered structures are independently manipulated by modulating the design parameters of topographical templates. Moreover, a set of design strategies are proposed to precisely construct the 3D non-trivial structures with T-junctions and jogs at desired locations and layers. Importantly, the simulations clarify the experimental observations about the formation range of 3D interconnected structures, and manifest that the vertical interconnections depend strongly on the template thickness. These results provide detailed insights into the nature of 3D assembled structures, and furthermore offer promising strategies for constructing the 3D device-oriented elements such as T-junctions, jogs and interconnections.

Hierarchical microstructures self-assembled from A(BC)n multiblock copolymers confined between two solid surfaces were explored by dissipative particle dynamics simulations. The strategy using confinement allows us to generate hierarchical microstructures with various numbers and different orientations of small-length-scale lamellae. Except for the hierarchical lamellar microstructures with parallel or perpendicular arrangements of small-length-scale lamellae, the coexistence of two different hierarchical lamellae was also discovered by varying the film thickness. The dynamics of hierarchical microstructure formation was further examined. It was found that the formation of the hierarchical microstructures exhibits a stepwise manner where the formation of small-length-scale structures lags behind that of large-length-scale structures. The present work could provide guidance for controllable manufacture of hierarchical microstructures.

Self-assembly behaviors of cylinder-forming diblock copolymers directed by an array of anisotropic nanoposts with elliptical shape are explored by large cell simulations of self-consistent field theory. The strategy using elliptical nanoposts allows us to generate long-range order cylinders with single orientation by suppressing other selections of cylinder alignment. The anisotropy of nanoposts plays a significant role in improving the tolerance of commensurability conditions between the dimensions of nanopost lattices and the period of cylinders. Moreover, the local defect structures could be regulated through varying the spacing and orientation of elliptical nanoposts. This work may provide useful guidelines for designing the topographical templates and lay the groundwork for fabricating well-ordered nanostructures of block copolymer lithography.

A theoretical approach coupling dynamic self-consistent field (SCF) theory for inhomogeneous polymeric fluids and variable cell shape (VCS) method for automatically adjusting cell shape and size is developed to investigate ordered microstructures and the ordering mechanisms of block copolymer melts. Using this simulation method, we first re-examined the microphase separation of the simplest AB diblock copolymers, and tested the validity and efficiency of the novel method by comparing the results with those obtained from the dynamic SCF theory. An appropriate relaxation parameter of the VCS method effectively accelerates the system towards a stable morphology without distortions or defects. The dynamic SCF/VCS method is then applied to identify the richness morphologies of ABC star terpolymers and explore the ordering mechanisms of star terpolymer melts quenched from homogenous states. A diverse range of ordered microstructures, including two-dimensional tiling patterns, hierarchical structures and ordinary microstructures, are predicted. Three types of ordering mechanisms, namely, one-step, quick-slow and step-wise procedures, are discovered in the disorder-to-order transition of ABC star terpolymers. The procedures of microphase separation in the ABC star terpolymer melts are remarkably affected by the composition of star terpolymers and the strength of interaction parameters.

Mechanical properties of nanoparticle-tethering polymer systems were investigated by molecular dynamics simulations. The stress–strain behavior of nanoparticle-tethering polymers as a function of interaction strength and architecture parameters (polymer length and particle size) was examined. As the interaction strength between nanoparticles and polymers increases, the stress increases. The effects of architecture parameters on the stress are relatively complicated. With decreasing polymer length or increasing particle size, the stress increases at smaller strain, while at larger strain, the stress first increases and then decreases. The tensional moduli were also found to be dependent on the interaction strength and architecture parameters. The nanoparticle-tethering polymers exhibit enhanced mechanical properties relative to neat polymers and nanoparticle/polymer blends. It was found that the bond orientation, bond stretching, and nonbonding interaction play important roles in governing the mechanical properties of the nanoparticle-tethering polymer systems. The simulation results were finally compared with available experimental observations, and an agreement was obtained. The results gained through these simulations may provide useful guidance for designing high-performance hybrid materials.

Self-assembly behavior of rod–coil–rod poly(γ-benzyl-l-glutamate)-b-poly(ethylene glycol)-b-poly(γ-benzyl-l-glutamate) (PBLG-b-PEG-b-PBLG) triblock copolymers with various PBLG block lengths in aqueous solution was investigated. The PBLG-b-PEG-b-PBLG triblock copolymers are able to self-assemble into vesicles when PBLG block length is relatively short. Meanwhile, the initial polymer concentration was found to have influence on the self-assembly. Giant vesicles can be observed when the initial concentration is high. Dissipative particle dynamics (DPD) simulations about the vesicles revealed that the rigid rod blocks could be aligned parallelly with each other to form the monolayer vesicles wall. When the PBLG block length in the PBLG-b-PEG-b-PBLG triblock copolymers increases, the aggregate morphologies were observed to transform from vesicles to spherical micelles. Based on the experimental and simulation results, we proposed a possible mechanism of the morphological transitions of the rod–coil–rod triblock copolymer aggregates.

A novel copolymer, β-cyclodextrin-b-poly(L-glutamic acid) (β-CD-b-PLGA), was synthesized by ring-opening polymerization and subsequent hydrolysis reaction. The β-CD-b-PLGA copolymer possesses an oligosaccharide β-CD segment and a polypeptide PLGA segment, with chemical structure resembling natural glycoprotein. The copolymers were applied in regulating the crystallization of calcium carbonate. The effects of the concentration of copolymers and calcium ions were systemically investigated. Various morphologies, including rhombohedra, rod, pseudo-dodecahedra and rosette-like structures, were obtained by adjusting the polymer and Ca2+ concentrations of the initial solution. Investigation of the pseudo-dodecahedra growth mechanism indicates that the copolymers mediate amorphous calcium carbonate formation initially, and then regulate the meso-scale self-assembly of CaCO3 subunits. The morphology variation is influenced by the binding of β-CD-b-PLGA chains on specific crystal faces combined with the steric repulsive force of β-CD-b-PLGA chains.

Charge-regulated synthesis of triangular prisms in aqueous solution using self-assembled polyelectrolyte micelles as templates is described in detail. Micelles formed from amphiphilic polystyrene-block-sulfonated poly(1,3-cyclohexadiene) (PS-b-sPCHD) serve as templates to direct the formation of novel triangular prisms of CuCl2 single crystals. We demonstrate that the edge lengths of these triangular prisms can be easily tailored at room temperature from the nanoscale to the mesoscale by simply adjusting the ratio of charged micelles to protons in the solution. This approach can be extended to the preparation of different ordered crystal structures with a precision hard to achieve via other approaches.

We developed a self-consistent field theory to study the solvation effect in polyelectrolyte solutions by taking into account the dipolar feature of polar solvents. A Langevin Poisson–Boltzmann equation describing the electrostatic interactions was derived at the mean-field level and numerically solved by an ad-hoc direct spectral algorithm. This method enables the SCFT to be implemented in real space. The developed self-consistent field model was applied to salt-free concentrated solutions of diblock polyampholytes and charged–neutral diblock copolymers. It was found that an increase in the magnitude of dipole moments can lead to an increase in the effective dielectric constant and thereby the change of the phase behaviors. As the magnitude of the dipole moment increases, the segregation between dissimilar blocks becomes strong, and the lamellar spacing undergoes a non-monotonic variation where the spacing first decreases and then increases to reach a plateau. The proposed calculation method can be extended to the solutions of polyelectrolytes with different architectures and polar solutions containing added salts.

We employ self-consistent field theory and dissipative particle dynamics simulation to investigate self-assembly of graft copolymers in a backbone-selective solvent. It is found that the graft copolymers are capable of forming hierarchical vesicles such as multilamellar vesicles and large-compound vesicles in dilute solution. The self-consistent field calculations demonstrate that the formed hierarchical vesicles are thermodynamically stable, due to the nature of the graft copolymers. In addition, the dissipative particle dynamics simulations reveal that the pathway of the spontaneous vesicle formation in an initially homogeneous dilute solution is hierarchical. Unilamellar vesicles are first formed along the “standard” pathway, then gradually coalesced to compound or multilamellar sub-vesicles, and finally organized into large-compound or multilamellar vesicles. The results demonstrate the possibility of using two-component copolymers to generate stable aggregates with complex structures, and suggest a versatile and promising route to obtain the advanced nanostructured materials.

We extended self-consistent field theory to explore self-assembly behavior of linear multiblock copolymers consisting of alternative rod and coil blocks. Such rod–coil multiblock copolymers are found to be capable of self-assembling into hierarchical smectic microstructures. For the copolymers with long rod end block, lamellae-in-lamellar structures containing two smectic C phases at small and large length scales were observed. It was found that the hierarchical smectic structures exhibit not only double periodicities in overall structure but also double orientational orders of rod blocks. Additionally, these hierarchical smectic structures can be tailed by tuning the relative length of the coil blocks. For the copolymers with long coil end block, the multiblock copolymers can self-assemble into hierarchical lamellar structures with smectic phases only at the small length scale. The findings gained through the present study may offer valuable information for understanding the self-assembly behavior of complicated rod–coil copolymers and designing polymeric materials with advanced properties.

A novel linear-dendron-like polyampholyte, poly(l-lysine)-b-D2-poly(l-glutamic acid) [PLL-b-D2-(PLGA)4], where D2 is the second generation of poly(amido amine), was prepared by hydrolyzing poly(ε-benzyloxycarbonyl-l-lysine)-b-D2-poly(γ-benzyl-l-glutamate) copolymer which was synthesized via a combination of ring-opening polymerization and click chemistry. The pH-responsive self-assembly behaviors of PLL-b-D2-(PLGA)4 were investigated in detail. It is found that PLL-b-D2-(PLGA)4 can self-assemble into PLGA-core aggregates at acidic pH and PLL-core aggregates at alkaline pH, which was accompanied with the coil-to-helix conformational transition of PLGA and PLL segments, respectively. The self-assembled aggregates with various morphologies, such as large compound micelles, worm-like micelles, large compound vesicles, simple vesicles, and rigid tubular structures have been obtained in “schizophrenic” aggregation process with simply increasing the solution pH. The hierarchical assembled fractal structures of PLL-b-D2-(PLGA)4 were observed during the solvent evaporation at high pH value.

Self-assembly behavior of an ABC triblock copolymer, poly(ethylene glycol)-b-polystyrene-b-poly(ε-caprolactone) (PEG-b-PS-b-PCL), in aqueous media is presented. The formed micelle structures were analyzed by using transmission electron microscopy, scanning electron microscopy, and laser light scattering. Various fascinating multicompartmental aggregates, including multilamellar vesicles, cylinder-containing vesicles, entrapped vesicles, and porous large compound micelles, were prepared from four copolymers with various block lengths of PEG and PS. The phase separation of hydrophobic PS and PCL blocks, as well as the hydrophilic/hydrophobic balance, plays a crucial role on the self-assembly behaviors. The mechanism regarding the formation of these fascinating aggregates is also suggested.

Self-assembly of mixture systems containing poly(acrylic acid)-g-poly(γ-benzyl-l-glutamate) graft copolymers (PAA-g-PBLG) and PBLG homopolymers in aqueous solution was investigated by both experiments and computer simulations. It was found that the aggregate morphologies, such as rods, curved rods, and toroids, could be tuned by the homopolymer content. The toroidal micelles with uniform size were formed when the homopolymer content in the hybrid aggregates is higher. The effect of added water content on the toroid formation process was studied. Rods and curved rods were observed sequentially before formation of toroids. We also performed dissipative particle dynamics (DPD) simulations to verify the structure transition and explore the formation mechanism of the toroidal aggregates. The DPD results are in good agreement with the experimental findings and provide additional information such as chain distribution in aggregates, which is difficult to be gained through experiments. On the basis of the experimental and simulation results, the formation mechanism of the toroidal micelles was suggested.

In the present work, we designed a multicompartment gel by taking advantage of the ABC graft copolymer with a solvophilic A backbone and solvophobic B and C grafts. The mechanical properties of such designed gels were investigated by a combination of dissipative particle dynamics simulation and a nonequilibrium deformation technique. The extensional moduli of multicompartment gels were found to be dependent on polymer concentration and architectural parameters of the graft copolymers (the sequence of graft arms and the position of the graft points). The graft copolymer solutions undergo a sol–gel transition as the polymer concentration increases. This leads to an abrupt increase in the extensional modulus. The studies also revealed that the multicompartment gels of graft copolymers exhibit higher extensional moduli than those of nonmulticompartment gels of graft copolymers and triblock copolymer gels. The position of graft points plays another important role in determining the extensional moduli of the multicompartment gels. The effects of graft positions on the gel modulus were found to be associated with the bridging fraction of graft copolymer chains. The results gained through the present work may provide useful guidance for designing high-performance gels.

CaCO3 crystallization behavior was studied in the presence of a thermo-responsive polypeptide copolymer, poly(N-isopropyl acrylamide)-b-poly(L-glutamic acid) (PNIPAM-b-PLGA). At lower temperatures, the copolymer dissolved well and the unimers mediated the formation of rosette-like calcite crystals through a mesoscale assembly process. At higher temperatures, the copolymer self-assembled into micelles with PNIPAM as the core and PLGA as the shell. The micelles mediated the formation of coral-like aragonite fiber clusters at a high micelle concentration, while fewer aragonite fibers were generated at a low concentration and vaterite crystals were obtained instead of aragonite. The time-resolved experiment revealed that the aragonite fibers were formed through a solution–precursor–solid (SPS) process via a transient polymer-induced liquid-precursor (PILP) phase. The new findings through the experiments can enrich our existing knowledge of biomimetic mineralization and provide useful information for designing functional materials.

We discovered that micelles of a thermo-responsive polypeptide-based copolymer are able to direct growth of barium carbonate (BaCO3) in the form of nanobelts. The BaCO3 nanobelts tend to grow around a formed crystal, and curl into a spiral superstructure.

Janus nanoparticles possessing two spherical caps usually exhibit strong interfacial affinity, providing the possibility to create nanocomposites with controlled arrangement of nanoparticles. Here we extended the self-consistent field theory/density functional theory to study the position of the Janus nanoparticles in block copolymer scaffolds. The results demonstrated that the Janus nanoparticles exhibit a size-dependent distribution and orientation in block copolymer scaffolds. The smaller Janus nanoparticles are almost uniformly dispersed in the matrix, while the larger Janus nanoparticles are strongly attached to the interface. Meanwhile, the orientational order parameters of the Janus nanoparticles increase with increasing their sizes. The relative size of the spherical caps also shows a pronounced effect on the Janus nanoparticle distributions. As one of the spherical caps becomes smaller, the Janus nanoparticles partly migrate to the domains preferred by the larger spherical caps, but still remain strongly attached to the interface. The present study can provide an insight into the effect of size on the interfacial activity of the Janus nanoparticles, guiding the design of functional materials with advanced properties.

Hybrid polymeric micelles self-assembled from a mixture containing poly(γ-benzyl-l-glutamate)-block-poly(ethylene glycol) (PBLG-b-PEG) block copolymer and gold nanoparticles (AuNPs) were prepared. The effect of AuNPs on the self-assembly behavior of PBLG-b-PEG was studied both experimentally by transmission electron microscopy, scanning electron microscopy, and laser light scattering and computationally using dissipative particle dynamics (DPD) simulations. It was found that, the pure PBLG-b-PEG block copolymer self-assembles into long cylindrical micelles. By introducing AuNPs to the stock block copolymer solution, the formed aggregate morphology transforms to spherical micelles. The DPD simulation results well reproduced the morphological transformations observed in the experiments. And the simulation revealed that the main reason for the aggregate morphology transformation is the breakage of ordered packing of PBLG rods in micelle core by the added nanoparticles. Moreover, from the DPD simulations, the distribution information on nanoparticles was obtained. The nanoparticles were found to prefer to locate near the core/shell interface as well as in the core center of the micelles. The combination of experimental and simulation methods lead to a comprehensive understanding of such a complex self-assembly system.

Self-assembly behavior of mixture systems containing poly(γ-benzyl-l-glutamate)–poly(ethylene glycol) graft (PBLG-g-PEG) and block (PBLG-b-PEG) copolymers in aqueous solution was investigated by both experiments and computer simulations. Pure graft copolymers self-assembled into vesicles, and pure block copolymers aggregated into spherical micelles or vesicles, while, for the mixture systems, hybrid cylindrical micelles were observed. In addition to the experimental observations, self-consistent field theory (SCFT) simulations were performed on the self-assembly behavior of graft/block copolymer mixtures. Simulation results reproduced the morphological transitions observed in the experiments. Moreover, from the SCFT simulations, the chain distributions of copolymers in the aggregates were obtained. For the hybrid cylindrical micelles, block copolymers were found to mainly locate at the ends of aggregates, which prevents the fusion of cylinders to vesicles. By combining experimental findings with simulation results, the mechanism regarding the morphological transition of the aggregates formed by graft/block copolymer mixtures is proposed.

Recently, increasing attention has been given to the self-assembly behavior of polypeptide-based copolymers. Polypeptides can serve as either shell-forming or core-forming blocks in the formation of various aggregates. The solubility and rigidity of polypeptide blocks have been found to have a profound effect on the self-assembly behavior of polypeptide-based copolymers. Polypeptide graft copolymers combine the advantages of a grafting strategy and the characteristics of polypeptide chains and their self-assembly behavior can be easily adjusted by choosing different polymer chains and copolymer architectures. Fabricating hierarchical structures is one of the attractive topics of self-assembly research of polypeptide copolymers. These hierarchical structures are promising for use in preparing functional materials and, thus, attract increasing attention. Computer simulations have emerged as powerful tools to investigate the self-assembly behavior of polymers, such as polypeptides. These simulations not only support the experimental results, but also provide information that cannot be directly obtained from experiments. In this feature article, recent advances in both experimental and simulation studies for the self-assembly behavior of polypeptide-based copolymers are reviewed.

The phase behavior of graft copolymers dissolved in a graft-selective solvent was studied by using self-consistent field theory. The effects of polymer concentration and molecular architecture, i.e., the number of junctions and the position of the first junction on the phase behavior were investigated. Phase diagrams were mapped out according to the calculation results. The detailed studies on the microstructures revealed that the graft copolymers can have either a local crosslinked structure or a global crosslinked structure, yielding a vital material for reversible physical gels. In addition, the density distributions and bridging fractions were calculated to understand the filling of solvents and packing of graft copolymers in the ordered structures of the gels. The understanding of the microstructures of graft copolymers in concentrated solution provides useful information for designing high-performance gels.

Using self-consistent field calculations, multicore micelles, such as the double-stranded superhelix, were discovered from the solution-state self-assembly of linear ABC terpolymers consisting of a solvophilic midblock and two mutually incompatible solvophobic endblocks. The multicore micelles were formed when the A and C endblocks self-associated into multiple incompatible solvophobic cores that were subdivided alternately by solvophilic B domains, thereby constructing hierarchical packing. The structures emerged depended on the relative lengths of the blocks and the solubility of the midblocks. According to the calculation results, diagrams of the observed structures as a function of the block length and midblock solubility were constructed. The results obtained can enrich our existing knowledge of the hierarchical assembly of copolymers and provide useful information for mimicking complex biological systems.

Self-assembly of AB diblock copolymer/C homopolymer blends with reversible supramolecular interactions was studied by real-space self-consistent field theory. The reversible bond is formed between the B free end of the AB diblock copolymers and one end of the C homopolymers, and thereby the supramolecular blends consist of the AB diblock copolymers, C homopolymers, and supramolecular ABC terpolymers. The constitutions of the blends are dependent on the bonding strength and blend ratio. The change of the bonding strength and blend ratio leads to a series of hierarchically ordered alternating nanostructures. In these alternating nanostructures, the C homopolymers exhibit a swollen effect on the C substructures, and the coordination number of C cylinders decreases as the bonding strength increases. To gain the information about the hierarchical nanostructures in details, one-dimensional density profiles were plotted. The results were finally compared with the existing experimental findings, and an agreement was shown. The obtained results provided an insight into the role of the supramolecular interactions on the hierarchical nanostructure formations.

Using dissipative particle dynamics simulation, structural evolution from concentric multicompartment micelles to raspberry-like multicompartment micelles self-assembled from linear ABC triblock copolymers in selective solvents was investigated. The structural transformation from concentric micelles to raspberry-like micelles can be controlled by changing either the length of B blocks or the solubility of B block. It was found that the structures with B bumps on C surface (B-bump-C) are formed at shorter B block length and the structures with C bumps on B surface (C-bump-B) are formed at relative lower solubility of B blocks. The formation of B-bump-C is entropy-driven, while the formation of C-bump-B is enthalpy-dominated. Furthermore, when the length of C blocks is much lower than that of B blocks, an inner-penetrating vesicle was discovered. The results gained through the simulations provide an insight into the mechanism behind the formation of raspberry-like micelles.

We employed self-consistent field theory to elucidate the mechanical properties of A(BC)n multiblock copolymer in hierarchical lamellae-in-lamellar structures. Extension and shear moduli as well as Young’s modulus have been characterized. A remarkable improvement of elastic modulus in the process of morphology transformation from lamella to lamellae-in-lamella was discovered. The mechanical response of hierarchical lamella is also shown to be dependent on the number of small-length-scale structures. From the physical origin of the enhanced mechanical properties, it was found that internal energy and conformational entropy of BC blocks play a predominate role in improving the elastic moduli in the hierarchical lamellar structures. Our findings are in agreement with the recent experimental observations and also yield guidelines for designing hierarchical materials with improved properties.

A degradation controllable composite material was designed to resist the degradation rate variation caused by pH change. The degradation controllable composite materials were prepared by incorporating lysozyme-loaded Ca-alginate microparticles into chitosan matrix. In these materials, the Ca-alginate microparticle carriers can fast release large amount of lysozyme at higher pH to compensate the decrease in enzyme activity, and decrease the release amount at lower pH when lysozyme presents a high activity. Degradation study revealed that the difference among the degradation profiles at various pH values is significantly decreased, indicating an anti-pH-interference effect of the composite films. The result well proved our designing ideas. In addition, the power law and Michaelis equations were used to figure out the inherent relationship between the drug release behavior and the degradation process. Finally, the fluorescence microscopy observation and MTT assay show that the degradation controllable materials have good biocompatibility, which allow adhesion and proliferation of the examined cells.

Two new urea derivatives bearing a tricarbonylchromium moiety showed high selectivity and sensitivity toward carboxylate anions in competitive hydrogen bonding solvents, which can be monitored by the changes of the IR spectrum of the carbonyl groups complexed with the organic metal.

Using real-space self-consistent field theory, we explored hierarchical microstructures self-assembled from A(BC)n multiblock copolymers. The multiblock copolymers were classified into two types in terms of relative magnitude of A/B and A/C interaction strengths: one is that χABN is less than or equal to χACN, and the other is that χABN is greater than χACN. For both cases, the multiblock copolymers can self-assemble into hierarchically ordered microstructures with two different length scales. For χABN ≤ χACN, various hierarchical microstructures, such as cylinders-in-lamellae∥, lamellae-in-lamella∥, cylinders-in-cylinder∥, and spheres-in-sphere∥, were observed. In these microphases, the small-length-scale structures and the large-length-scale structures are packed in the doubly parallel forms. It was found the number of internal small-length-scale structures can be tailored by tuning the number of BC block and the interaction strength between A and BC blocks. For χABN > χACN, in addition to the parallel packed hierarchical structures, the multiblock copolymers can self-organize into perpendicular packed hierarchical structures, in which the structures with small periods are arranged perpendicular to structures with large periods. These perpendicular packed hierarchical structures were found to be only stable at higher value of χBCN.

Combining the self-consistent field theory (SCFT) and the density functional theory (DFT), we investigated the self-assembly behavior of AB diblock copolymer tethered single spherical particle P (ABP molecules). Two cases were studied: one is where the particles are chemically neutral to both A and B blocks, and the other is where the particles are unfavorable to neither of the two blocks. For neutral particles, the ABP molecules self-assemble to typical equilibrium microstructures, such as lamellae and cylinders. The P particles are localized in B block domains, and the size of particles can influence the phase behavior. For unfavorable particles, the ABP molecules microphase separate to form distinct ordered structures. Hierarchical structures, such as cylinders with cylinders at the interfaces and lamellae with cylinders at the interfaces, were observed. These resulting hierarchical structures are mainly determined by two parameters: A block fraction fA and particle size RP. On the basis of the calculation results, phase diagrams were constructed.Keywords: diblock copolymer; hierarchical structures; nanoparticles; self-assembly; self-consistent field theory

We discovered that micelles of a thermo-responsive polypeptide-based copolymer are able to direct growth of barium carbonate (BaCO3) in the form of nanobelts. The BaCO3 nanobelts tend to grow around a formed crystal, and curl into a spiral superstructure.

Recently, increasing attention has been given to the self-assembly behavior of polypeptide-based copolymers. Polypeptides can serve as either shell-forming or core-forming blocks in the formation of various aggregates. The solubility and rigidity of polypeptide blocks have been found to have a profound effect on the self-assembly behavior of polypeptide-based copolymers. Polypeptide graft copolymers combine the advantages of a grafting strategy and the characteristics of polypeptide chains and their self-assembly behavior can be easily adjusted by choosing different polymer chains and copolymer architectures. Fabricating hierarchical structures is one of the attractive topics of self-assembly research of polypeptide copolymers. These hierarchical structures are promising for use in preparing functional materials and, thus, attract increasing attention. Computer simulations have emerged as powerful tools to investigate the self-assembly behavior of polymers, such as polypeptides. These simulations not only support the experimental results, but also provide information that cannot be directly obtained from experiments. In this feature article, recent advances in both experimental and simulation studies for the self-assembly behavior of polypeptide-based copolymers are reviewed.

A novel copolymer, β-cyclodextrin-b-poly(L-glutamic acid) (β-CD-b-PLGA), was synthesized by ring-opening polymerization and subsequent hydrolysis reaction. The β-CD-b-PLGA copolymer possesses an oligosaccharide β-CD segment and a polypeptide PLGA segment, with chemical structure resembling natural glycoprotein. The copolymers were applied in regulating the crystallization of calcium carbonate. The effects of the concentration of copolymers and calcium ions were systemically investigated. Various morphologies, including rhombohedra, rod, pseudo-dodecahedra and rosette-like structures, were obtained by adjusting the polymer and Ca2+ concentrations of the initial solution. Investigation of the pseudo-dodecahedra growth mechanism indicates that the copolymers mediate amorphous calcium carbonate formation initially, and then regulate the meso-scale self-assembly of CaCO3 subunits. The morphology variation is influenced by the binding of β-CD-b-PLGA chains on specific crystal faces combined with the steric repulsive force of β-CD-b-PLGA chains.

Mineralization behaviour of CaCO3 in the presence of polypeptide vesicles self-assembled from poly(L-glutamic acid)-block-poly(propylene oxide)-block-poly(L-glutamic acid) (PLGA-b-PPO-b-PLGA) triblock copolymers was studied. Under the mediation of PLGA-b-PPO-b-PLGA vesicles, CaCO3 fibre clusters were obtained. The structure of fibres could be regulated by the mineralization temperature, copolymer composition, copolymer concentration, and Ca2+ concentration. The investigation of the fibre growth process suggested a solution–precursor–solid mechanism via transient amorphous precursors. Since the polypeptide vesicles could serve as both the modifier and template for the formation of amorphous precursors, the properties of amorphous precursors were affected by the vesicular structure. The variation in the fibre structure was ascribed to the different aggregation and transformation behaviours of amorphous particles. These findings can provide useful information for the design of novel inorganic materials with fibrous structures and enrich our existing knowledge of the crystallization process from the amorphous phase.

In this work, the structures and topological defects of striped patterns self-assembled from rod–coil diblock copolymers confined on spherical substrates were examined using dissipative particle dynamics simulations. The stripes were formed by orderly packed rod blocks that were stabilized by coil blocks in solvents. Three types of disclinations with charges of +1, +1/2, and −1/2 and dislocations were observed in the striped patterns. The sum of the disclination charges was always +2, which is consistent with the Poincaré–Hopf theorem. Two categories of local defect stripe patterns were observed, namely, spiral-like and ring-like. The structures and surface densities of the defects were found to depend on various parameters, including the rigidities of the rod blocks, the radii of the spheres and the hydrophobicities of the rod blocks. The predictions were compared with our previous experimental observations and agreement was found. This work provides a method for producing striped patterns on curved substrates and can serve as a theoretical support for preparing nanoparticles with complex surface structures.

The ability to design and fabricate highly ordered superstructures from nanoscale particles remains a major scientific and technological challenge. Patchy nanoparticles have recently emerged as a novel class of building units to construct functional materials. Using simulations of coarse-grained molecular dynamics, we propose a simple approach to achieve soft nanoparticles with a self-patchiness nature through self-assembly of tethered copolymers with a sequence of inner solvophilic and outer solvophobic blocks. As building units, the patch-like nanoparticles are directed to further assemble into a rich variety of highly ordered superstructures via condensation–coalescence mechanisms. The growth kinetics of the superstructures obeys the kinetic model of the step-growth polymerization process. Our simulations also demonstrate that the intermediate patch-like nanoparticles and the final assembled superstructures can be rationally tuned by changing the number and the composition of the tethered copolymer chains. This strategy of copolymer functionalization conceptually enables the design and fabrication of highly ordered superstructures of nanoparticle ensembles with new horizons for promising applications in soft nanotechnology and biotechnology.

Charge-regulated synthesis of triangular prisms in aqueous solution using self-assembled polyelectrolyte micelles as templates is described in detail. Micelles formed from amphiphilic polystyrene-block-sulfonated poly(1,3-cyclohexadiene) (PS-b-sPCHD) serve as templates to direct the formation of novel triangular prisms of CuCl2 single crystals. We demonstrate that the edge lengths of these triangular prisms can be easily tailored at room temperature from the nanoscale to the mesoscale by simply adjusting the ratio of charged micelles to protons in the solution. This approach can be extended to the preparation of different ordered crystal structures with a precision hard to achieve via other approaches.

Polypeptide copolymers can self-assemble into diverse aggregates. The morphology and structure of aggregates can be varied by changing molecular architectures, self-assembling conditions, and introducing secondary components such as polymers and nanoparticles. Polypeptide self-assemblies have gained significant attention because of their potential applications as delivery vehicles for therapeutic payloads and as additives in the biomimetic mineralization of inorganics. This review article provides an overview of recent advances in nanostructures and bioapplications related to polypeptide self-assemblies. We highlight recent contributions to developing strategies for the construction of polypeptide assemblies with increasing complexity and novel functionality that are suitable for bioapplications. The relationship between the structure and properties of the polypeptide aggregates is emphasized. Finally, we briefly outline our perspectives and discuss the challenges in the field.

Self-consistent field theory with a dynamic extension is exploited to investigate the kinetics of the lamellar formation of symmetric block copolymers under the direction of external fields. In particular, three types of directed self-assembly methods – a permanent field for chemo-epitaxy, a dynamic field for zone annealing and an integrated permanent/dynamic field – are examined. For the chemo-epitaxy involving sparsely prepatterned substrates or zone annealing, the block copolymers generally develop into polycrystalline nanostructures with multiple orientations due to the lack of strong driving forces for eliminating the long-lived imperfections in a limited time. As the integrated chemo-epitaxy and zone annealing method is applied to the block copolymer systems, single-crystalline nanostructures with precisely registered orientations are achieved in a short annealing time owing to the mutual acceleration of defect annihilations, which cannot be produced by the conventional techniques alone. Furthermore, the integrated method allows the rapid fabrication of well-ordered nanostructures on the extremely sparse prepatterned substrates. Our theoretical work may serve to rationalize the faster modern nanolithographic fabrication of smaller microelectronic components using lower-spatial-frequency templates.