Self-assembly of rod–coil block copolymers

Abstract

We present a self-consistent field theory model for the self-assembly behavior of rod-coil block copolymers. The orientational interactions between the rods were modeled through a Maier-Saupe interaction, while the enthalpic interactions between rods and coils were modeled through a standard Flory-Huggins approach. We outline a "real-space" numerical approach to solve the self-consistent field equations for such rod-coil block copolymers. A major focus of our work is upon the nonlamellar phases observed in the experiments on such polymers. To develop a physical understanding of these phases and their regimes of occurrence, we compute the two-dimensional phase diagram for our model. The latter shows significant departures from the one-dimensional phase diagram, but matches qualitatively with the existing experimental results. We also present scaling arguments that rationalize the numerical results for the self-assembly behavior.

Secondary Structure-Induced Micro- and Macrophase Separation in Rod-Coil Polypeptide Diblock, Triblock, and Star-Block Copolymers

“…The presence of a rodlike block induces essentially two specific features: a high conformational asymmetry in the phase diagram and liquid-crystalline interactions among the rigid blocks. 1 These differences, which have been rationalized both theoretically [1][2][3][4] and experimentally, [5][6][7][8][9] became more evident when the rodlike block occupies the greatest part of the overall volume fraction in the system. Traditionally, the study of rod-coil block copolymers has been carried out on two main classes of systems: those on which the rodlike block is embodied by a π-conjugated polymer [10][11][12][13][14] and those in which this block is constituted by a polypeptide [15][16][17][18] or other polymer 5,19 exhibiting a helical secondary structure.…”

Self-assembly of rod-coil block copolymers from weakly to moderately segregated regimes

“…More recently, new block copolymers have surfaced bearing mesogenic units or rigid blocks, which confer to these systems a liquid crystalline behaviour [1][2][3][4]. Not only these systems are interesting from a fundamental and theoretical point of view, but they have also a high value and potential in applications such as optoelectronics, photovoltaics [5][6][7][8][9][10][11], bioapplications [12], sensoring, etc.…”

Self-Assembly of Polypeptide/π-Conjugated Polymer/Polypeptide Triblock Copolymers in Rod−Rod−Rod and Coil−Rod−Coil Conformations

“…[1][2][3] Although the phase diagram of the coil-coil copolymers is now well understood both experimentally and theoretically, 4-6 the rod-coil self-assembly is still under intensive theoretical and experimental investigation. 2,[7][8][9] Recently, in view of more controlled morphologies and enhanced properties, more complicated molecular architectures such as rod-rod diblock copolymer 10,11 or rod-coil-rod 12 and coil-rod-coil 13,14 triblock copolymers have also become the object of several studies. The rigidity of the rod blocks can be achieved either by polypeptides exhibiting R-helical secondary structure or with π-conjugated polymers.…”