Adsorption of amphiphilic graft copolymers in solvents selective for the grafts on a lyophobic surface: a coarse-grained simulation study

Abstract

The sorption of graft copolymers on surfaces attractive only for the backbone and its effect on the conformational behavior of adsorbed/desorbed chains in solvents good for the grafts and poor for the backbone was studied by coarse-grained computer simulations. It was found that the sorption and conformational behavior are very complex and are results of an intricate interplay of solvent quality (polymer-solvent interactions) and solvent strength (polymer-surface vs. solvent-surface interactions). Increasing grafting density and length of grafts protect the backbone against adsorption, but the behavior is non-trivial. A decrease in solvent quality promotes the adsorption, because it lowers the overall solubility, but the backbone collapses and the probability of backbone-surface contacts decreases, which simultaneously hinders the adsorption. The results of simulations are presented in the form of phase diagrams depicting the decisive features of the conformational and sorption behavior.

Associative properties of poly(ethylene glycol)–poly(vinyl acetate) comb-like graft copolymers in water

“…18 Amphiphilic graft copolymers have been investigated less extensively than their linear counterparts, due to the only recent development of controlled polymerization methods such as controlled/living radical polymerization, "grafting to" and "grafting from" techniques. [19][20][21][22] The solution behaviour of comb-like graft copolymers is influenced by the hydrophilic/hydrophobic features of the backbone and side chains: 19,23 under poor solvent conditions for the grafts, the individual polymer molecules are subjected to attraction forces that lead to collapse and macroscopic phase separation; conversely, in the case of soluble grafts and collapsing backbones, intramolecular aggregates are formed and stabilized against aggregation by the repulsive forces between the side chain coronas. From several studies, graft copolymers have been found to display a variety of selfassembled aggregates in water or organic solvents with diverse morphologies and structures, [24][25][26][27] the most exotic of which include petal-like micelles, spindle-like micelles, wormlike micelles, chiral helices, and snowflake-like suprastructures.…”

Interplay between surfactant self-assembly and adsorption at hydrophobic surfaces: insights from dissipative particle dynamics

“…Because the soft repulsion between DPD beads cannot prevent the solution from penetrating the walls, we separated the solution and wall domains by a reflecting surface and imposed mirror reflections when solution beads are about to cross the solid surface. The reflection scheme suppressed unphysical fluctuations in the solution density close the wall [46].…”

DL_MESO_DPD: development and use of mesoscale modelling software

“…The simplicity of DPD as a mesoscale modelling method makes it an ideal candidate to test phenomenological models for various kinds of molecules. A number of articles citing use of dl meso dpd follow this approach, examining self-assembly of chromonic liquid crystals [17], nanorod assembly in gyroid phases of diblock copolymers [91], gold nanoparticles with grafted copolymers [92], antiparallel molecular association in the formation of smectic A phases [93], aqueous mixtures of inorganic nanoparticles with tethered hydrophobic and amphiphilic copolymer chains [94], conformational behaviour of various polymer chains (including stars and dendrimers) in endothermic solvent mixtures [95], and adsorption of amphiphilic graft copolymers onto lyophobic surfaces [96].…”