Stabilizing Phases of Block Copolymers with Gigantic Spheres via Designed Chain Architectures

Abstract

It is generally believed that the spherical domains self-assembled from AB-type block copolymers are composed of the minority A blocks with a volume fraction of f A < 1/2. Breaking this generic rule so that the spherical domains are formed by the majority A blocks (f A > 1/2) requires mechanisms to drastically expand the stable region of spherical packing phases. Self-consistent field theory predicts that dendron-like AB-type block copolymers, composed of G – 1 generations of A blocks connected with the outermost generation of B blocks, exhibit a stable region of spherical packing phases extending to f A ∼ 0.7. The extremely expanded spherical regions shed light on the mechanisms governing the self-assembly of amphiphilic macromolecules, as well as provide opportunities to engineer complex spherical packing phases.

Binary Blends of Diblock Copolymers: An Efficient Route to Complex Spherical Packing Phases

“…[ 5 ] Moreover, a recent SCFT study by Qiang et al. [ 23 ] demonstrated that by employing specially designed dendritic AB‐type block copolymers, the spherical domains could be maintained up to resulting in large windows of FK A15 and phases in the phase diagram. These studies offer a good understanding of the formation of FK phases in single component systems composed of asymmetric block copolymers.…”

Control the Self‐assembly of Block Copolymers by Tailoring the Packing Frustration

“…regions of complex Frank‐Kasper spherical phases by designing the architectures of A‐blocks to release the packing frustration of A‐blocks inside the curvature of interfaces. [ 21‐22 ]…”

“…Nevertheless, the copolymer chains are not uniformly stretched in many self‐assembled nanostructures due to the constraint of filling the space uniformly. [ 20‐21 ] The nonuniformity of chain stretching causes an additional loss to the configurational entropy. For example, in the self‐assembly of AB diblock copolymers into the hexagonal array of cylinders, a circular shape of cylinder is preferred by the interfacial energy, whereas a hexagonal cylinder is favorable for reducing the nonuniformity of the stretching of the majority blocks to fill the hexagonal Voronoi cell uniformly, as shown in Figure 1.…”

Constituent Isomerism-Induced Quasicrystal and Frank–Kasper σ Superlattices Based on Nanosized Shape Amphiphiles

“…10,11 Often, the dodecagonal quasicrystal (DDQC) phase with 12-fold orientational symmetry and only one-dimensional (1D) translational symmetry are closely associated with F-K phases, due to similarities in local tetrahedral packing rules. [12][13][14] Complex F-K phases and the DDQC phase have not only been observed in broad soft matter systems, including diblock copolymers, [15][16][17][18][19][20][21][22][23] dendrimers, 13,[24][25][26][27][28][29][30][31] polymer colloids, 32 small molecular surfactants, [33][34][35] giant molecules, [36][37][38][39][40] and very recently, sugar-polyolefin conjugates, 41,42 but also mesoporous silica, 43,44 binary nanocrystal superlattices, 45,46 and DNA functionalized nanoparticles. 47,48 Several types of F-K phases only have considerably small differences between their overall free energies.…”