Polymorphism of self-assembled colloidal nanostructures of comblike and bottlebrush block copolymers

Abstract

Block copolymers comprising chemically different comblike or bottlebrush blocks can self-assemble in selective solvents giving rise to spherical or wormlike micelles or to polymersomes. The self-consistent field theoretical framework is used for predicting relation between the set of architectural parameters of the blocks (polymerization degrees of the main and side chains, density of grafting of the side chains to the backbone) and structural properties and morphology of the self-assembled aggregates. In particular, it is demonstrated that replacing linear blocks by architecturally symmetrical bottlebrush ones allows tuning the morphology of the self-assembled solution nanostructures.

Glossary

a :

monomer unit length

D :

thickness of the swollen corona formed by blocks A

F :

Helmholtz free energy

$M_{A,B}$ :

polymerization degrees of the main chains in A and B blocks

$n_{A,B}$ :

polymerization degrees of side chains in A and B blocks

$m_{A,B}$ :

polymerization degrees of spacers in A and B blocks

$N_{A},N_{B}$ :

total degrees of polymerization of blocks A and B, respectively

p :

aggregation number in a spherical micelle

R :

radius of the condensed core formed by insoluble blocks B

s :

surface area of the micellar core per block copolymer

$va^3$ :

excluded volume of a monomer unit in block A

$\gamma k_BT$ :

surface tension coefficient on the core-corona interface

$\phi _B$ :

volume fraction of monomer units of the B-block in the core

$\eta _{A,B}$ :

topological ratios in A and B blocks