A Morphological Transition of Inverse Mesophases of a Branched‐Linear Block Copolymer Guided by Using Cosolvents

Abstract

We report here a strategy for influencing the phase and lattice of the inverse mesophases of a single branched-linear block copolymer (BCP) in solution which does not require changing the structure of the BCP. The phase of the self-assembled structures of the block copolymer can be controlled ranging from bilayer structures of positive curvature (polymersomes) to inverse mesophases (triply periodic minimal surfaces and inverse hexagonal structures) by adjusting the solvent used for self-assembly. By using solvent mixtures to dissolve the block copolymer we were able to systematically change the affinity of the solvent toward the polystyrene block, which resulted in the formation of inverse mesophases with the desired lattice by self-assembly of a single branched-linear block copolymer. Our method was also applied to a new solution self-assembly method for a branched-linear block copolymer on a stationary substrate under humidity, which resulted in the formation of large mesoporous films. Our results constitute the first controlled transition of the inverse mesophases of block copolymers by adjusting the solvent composition.

Spherical Compound Micelles with Lamellar Stripes Self‐Assembled from Star Liquid Crystalline Diblock Copolymers in Solution

“…Functionalized, uniform, and stable polymer nano‐objects in water/organic solutions with controlled morphologies and sizes are extremely attractive . It is well known that the molecular architecture plays an important role during the self‐assembling process . Poly(ethylene oxide) (PEO) is popular to be used as the hydrophilic block due to its good performance and low cost.…”

The evolution of bicontinuous polymeric nanospheres in aqueous solution

“…24,25 Comparatively few examples of this morphology have been reported and so far the criteria for its formation are somewhat ambiguous. To date BPNs have been observed from triblock copolymers, [26][27][28] single 24 and double 29 comb-like block copolymers, branched copolymers, 30,31 Janus dendrimers 32 and block copolymers with ionic composition. 28,33,34 From the available reported examples, it would appear that structural complexity of the copolymer is a necessity for the formation of BPNs; however, we have recently reported their formation from simple amorphous block copolymers of poly(ethylene oxide)-blockpoly(butyl methacrylate) (PEO-b-PBMA).…”

Block copolymer microparticles comprising inverse bicontinuous phases prepared via polymerization-induced self-assembly

“…As microphase separation occurs, an area-minimizing surface is adopted in order to lower the total interfacial energy. Such minimal surfaces best satisfy this geometric constraint and have been observed for block copolymers both in melts65–67 and also in solution 13,19,68,69…”