Mesoscopic Simulation on the Phase Structure of Pluronic P105 Aqueous Solution

Abstract

The mesoscopic dynamic simulation (MesoDyn) has been carried out to investigate the phase structure and the aggregate properties of triblock copolymers (ethylene oxide)37 (propylene oxide)56 (ethylene oxide)37 (P105) in aqueous solution. A Gaussian chain model is successfully built according to the equivalent chain method and the Flory–Huggins interaction parameters, χ, used for determining the repulsions between different chain segments are computed. Simulation results show that P105 can form several microstructures including spherical micelles, ellipsoid micellar cluster, worm-like micelles, defective bicontinuous phase, and bicontinuous phase with increasing concentration. A special transition phase structure of P105 is found in the spherical micellar region. The dynamic evolution processes of spherical micelles are investigated by observing the induction time before phase separation and the changing of isosurface during phase separation. The influence of P105 concentration on the density of micelles at equilibrium state is also discussed, which shows that the increase of P105 concentration will lead to the decrease of micelles' amount. Two kinds of growth mechanisms during phase separation are discussed by MesoDyn simulation.

Coarse-Grained Modelling and Temperature Effect on the Morphology of PS-b-PI Copolymer

“…There are fusion and fission processes. These processes were also found in mechanism of spherical micelle formation [11,32]. In fusion process, the polymer in the same species will attach at the center of the aggregation.…”

“…Theoretical and experimental phase diagrams can be used to predict these morphologies formations. The morphology of a copolymer can be influenced by solvents [10,11,12], composition [1,13,14,15], temperature [13,15,16,17,18], external forces [19,20], additives [17,21,22,23,24,25,26], etc. Morphology of copolymer can be useful for a broad range of applications.…”

“…The material, which had specific properties and morphologies, would be employed under a various conditions. Clarification of these self-assembly processes are vital for deeply understanding the morphologies and morphological-related applications of copolymers [11,32].…”

“…The mesoscopic properties of copolymers can be successfully explained and predicted by the computational simulations using these algorithms [1,36,37,38,39]. Apart from the morphology prediction, DDF can explain and observe the mechanism via trajectory analyzes [11,32] which provides some insights for better understanding the formation of copolymers and their corresponding applications.…”

Molecular Dynamics Simulation of Nanocellulose-Stabilized Pickering Emulsions

“…At 0.1 of PB ratio, it was aligned with the thermodynamic profile that the phase separation had become more aggressive after 6000 time steps, as illustrated in Figure 9a. Likewise, the bead orders for PB at 0.4 and 0.8 ratio (Figure 9a,b, respectively) was recorded in a high order since the beginning, reflecting the thermodynamic profile of aggressive coalescence activities [39]. Both bead orders of NC and PB were relatively higher than the beads of water, suggesting the phase separation due to the hydrophobic effects of the beads trying to avoid contact with water molecules by "grouping" themselves into larger aggregates [40].…”