Molecular structure and phase behaviour of hairy-rod polymers

Abstract

Using dissipative particle dynamics simulations the relationship between molecular architecture and phase behaviour in model hairy-rod polymers is studied. In agreement with experimental and theoretical studies the phase behaviour is controlled by changes to the molecular structure, particularly the sidechain length and density, and the molecular interactions. For dense sidechains a lamellar structure is found, which becomes an inverted cylindrical phase when the sidechain density is lowered. The ordered phases become more stable on increasing sidechain length and on increasing the repulsion strength between the backbone and sidechains. In the absence of torsional potentials the structures are double-walled, i.e. layers are two polymer backbones thick, while single-walled structures are observed for polymers with torsional potentials

Multiscale Modeling of the Morphology and Properties of Segmented Silicone-Urea Copolymers

“…The main advantage of this method is its convenience for studying the self-assembly and the rheology of polymer systems and it describes the hydrodynamic interactions accurately [45]. Previously, it was used to study the morphology of various polymeric systems such as linear copolymers [46], polymer blends [47] and polymer brushes [48], as well as different rod-coil polymers [49]. Although there are some theoretical studies on different copolymers with low number of segments recently [50], to the best of our knowledge, this is the first systematic study on the self organizations of the hard and soft segments in segmented copolymers by DPD method.…”

Effect of side-chain asymmetry on the intermolecular structure and order-disorder transition in alkyl-substituted polyfluorenes

“…Hairy-rod polymers consist of a stiff backbone and flexible side chains that organize into alternating backbone and side-chain layers and experience an order-disorder transition (ODT) on heating [1][2][3][4][5]. Phase behavior of alkyl-substituted conjugated polymers can be understood in similar terms, and this was illustrated early with polythiophenes [6,7].…”

Microphase Separation of Phenylene Oligomers with Polymeric Side Chains: A Dissipative Particle Dynamics Study

“…Although there are many theoretical studies on hairy-rod polymers, morphological studies by DPD simulations are very few. [31] To our best knowledge, this is the first study on the self organizations of different side chains grafted on a rigid backbone by this method. DPD is a particle-based method in which the particles are not single atoms or molecules but rather molecular assemblies called beads.…”

“…[26][27][28][29] Recently, some studies on the selfassembly of polymer chains have shown that dissipative particle dynamics (DPD) simulations can be used to understand the relationship between the phase behavior and the molecular structure of model rod-coil and hairy-rod copolymers. [30,31] In this study, the microphase separated morphology of PS, PCL, POx, and PEO substituted PPP oligomers have been studied by the DPD simulations by mapping the predetermined interaction parameters between monomers of the PPP backbone and side-chain polymers. The DPD morphologies were compared to the experimental thinfilm morphologies as determined by AFM to understand the molecular arrangements better.…”