Self-assembly in Solutions of Amphiphilic Homopolymers: Computer Modeling and Analytical Theory

Abstract

The main feature of amphiphilic homopolymers is the effective surface activity of their monomer units, due to which, in selective solvent, they can aggregate into various structures, some of which resemble those formed by low-molecular surfactants and are prospective in many practical applications. The paper aims to address dilute solutions of amphiphilic homopolymers and to reveal the features of their self-assembly depending on the solvent selectivity and the relative solvent quality for solvophobic and solvophilic groups of monomer units. The calculations, performed in the framework of dissipative particle dynamics (DPD), allowed us to find various morphological aggregates, to analyze details of their structure, and to determine the field of their stability. The results are presented in the form of a diagram and described in the framework of original analytical theory.

DPD Modelling of the Self- and Co-Assembly of Polymers and Polyelectrolytes in Aqueous Media: Impact on Polymer Science

“…The behaviour of flexible polyelectrolytes and/or amphiphilic copolymers [69,91,105,106,174,178,193,[202][203][204][205][206], copolymers composed of linear and rigid blocks [127,128,207,208] and also hyperbranched copolymers [209][210][211] has been simulated and the decisive principles and trends of underlying processes have been described. Besides the above systems, the multicore assemblies forming in mixtures of linear copolymers [212], the self-assembling amphiphilic homopolymers [213], side-chain discotic liquid crystalline polymers [214], polymers tethered to nanoparticles and mixtures of copolymers with nanoparticles [215,216] and the 'shape amphiphiles' [217][218][219][220][221] have been successfully studied by DPD. Because the most promising and very intensively studied application of polymeric nanoparticles is the targeted transport of drugs in living organisms and their controlled release [17,21,23,25], several DPD and combined experimental-DPD studies have also been published recently [176,177,183,[222][223][224][225].…”

Fibril Assembly and Gelation of Macromolecules with Amphiphilic Repeating Units

“…The parameter set was chosen similar to ref and includes the following values: a PP = a HH = a SS = 25; the parameter describing the repulsion between P and H particles, which contributes to the effective surface activity of the macromolecule, was equal to a HP = 50 (strong immiscibility between H and P particles); parameters a PS and a HS account for the affinity of the solvent toward P and H groups, respectively. For studied chains with solvophobic backbone H and solvophilic pendant groups P, a PS was always lower than a HS .…”

“…That means every monomer of such macromolecule contains both solvophobic and solvophilic chemical residues. This leads to the strong surface activity of amphiphilic homopolymers and allows them to self-assemble into structures resembling those formed in living systems by proteins and lipids. − Despite the fact that usually amphiphilic block-copolymers are synthetic macromolecules, which are used to mimic assembly features of biomacromolecules, , the amphiphilic homopolymers have a few advantages over them, such as facilitated polymerization protocols, higher surface activity, and ability to form unimolecular structures . Moreover, as a result of intrinsic connectivity of amphiphilic units along the chain and hence poor entropy, these homopolymers have a lower critical association concentration compared to block-copolymer analogues …”

Flowerlike Multipetal Structures of Nanoparticles Decorated by Amphiphilic Homopolymers

“…Beads A connect to each other and form the polymer backbone, and beads B are side pendants. This minimalist model of the amphiphilic homopolymer proposed in ref has proved its effectiveness in describing a number of complex self-organization phenomena caused by the amphiphilic structure of the monomer units. − …”