The Morphology and Dynamics of Substrate Effects on Spinodal Decomposition in Binary Mixtures with Short‐Range Potential

Abstract

Summary: The SDSD of binary mixture with short‐range potential is numerically simulated in 3D by cell dynamic system (CDSs), focusing on the phase morphology and dynamics in the parallel cross‐sections. The formation mechanism and growth law of the wetting layer are analyzed taking thermal noise effects into account. The simulated results show that the phase inversion in the parallel cross‐sections can be observed near the substrate interface. Without thermal noise, the growth law of the wetting layer is simply logarithmic. However, when the strength of thermal noise is large enough, the LS growth law can be found for a short‐range surface field. The results demonstrate that thermal noise can increase the extent of phase separation and lead to a transformation between partial and complete wetting for the substrate interface. The evolution of the phase in the parallel cross‐sections obeys the LS growth law and is self‐similar regardless of the effects of thermal noise.Simulated pattern evolution at different values of z at τ = 1 000 with G = 0.magnified imageSimulated pattern evolution at different values of z at τ = 1 000 with G = 0.

Computational analysis of short‐range surface‐directed polymerization‐induced phase separation

“…They found that the surface enrichment layer grew logarithmically where there was no noise term, while it followed the LS growth law when noise was present. [37] The effect of critical quench depth on the wetting layer growth rate showed three different regimes: the pure diffusion-limited growth law for shallow quench (exponent 1/2), a logarithmic growth for intermediate quench, and the LS growth law for deepest quench were observed. [38] The results of off-critical quenches illustrated when the minority component was attracted to the surface, the growth of the wetting layer versus quench depth followed three different regimes similar to the critical quench case.…”

“…[27][28][29] Therefore, a wide range of studies on SDSD has been carried out. [13][14][15][16][17]26,[30][31][32][33][34][35][36][37][38][39][40][41][42][43] Jones et al [40] were the first to experimentally study the SDSD of a binary polymer mixture. They investigated phase separation of perdeuterated poly(ethylenepropylene) (d-PEP) and poly(ethylenepropylene) (PEP) as an isotopic polymer mixture under temperature quenches to T = 35 C and 76 C, at the presence of a surface preferably attracting d-PEP.…”

“…Yan and Xie [37][38][39] developed several models to investigate the effects of noise and quench depth on the morphology of surface-directed phase-separated binary mixtures. They found that the surface enrichment layer grew logarithmically where there was no noise term, while it followed the LS growth law when noise was present.…”

A computational study of multiple surface-directed phase separation in polymer blends under a temperature gradient

“…The surface-directed phase separation (SDPS) mechanism has attracted much attention and has been studied intensively for the past two decades as a means of fabricating binary materials with unique phase separated morphologies [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Surfaces have a great impact on the structure and associated properties of multiphase polymeric materials, including polymer blends.…”

“…They concluded that to model the SDPS and to be capable of replicating experimental observations, only one length scale should be used. Yan and Xie [15,16] simulated the SDPS in a polymer system by the cell dynamic system method. For the case of short range potential, they found that the wetting layer grows according to the logarithmic growth law if the noise term is absent, while it will grow according to the Lifshitz-Slyozov 1/3 growth law if the noise term is present.…”