Phase separation with multiple length scales in polymer mixtures induced by autocatalytic reactions

Abstract

A ternary polymer blend with two components photo-cross-linked independently in its miscible region undergoes phase separation, exhibiting morphology with multiple length scales. Contrary to the case of thermally induced phase separation, the morphology exhibits a unimodal-->multimodal transition. It is shown that these multiple length scales are caused by the inhomogeneous freezing kinetics of the cross-linking process. This inhomogeneity arises from the autocatalytic feedback driven by the couplings between concentration fluctuations and the photo-cross-linking reactions.

Dynamics of Liquid Structure Relaxation from Criticality after a Nanosecond Laser Initiated T-Jump in Triethylamine−Water

“…By Fourier transforming these images we could infer the magnitude of the scattering vector and from this we could estimate the average domain size. 63,64 Importantly, the Fourier transform of these images revealed a maximum in the scattering vector, which supports our assignment of spinodal decomposition to our observations. 10,54,64 Typical microscopic images and Fourier transforms are shown in Figure 6.…”

A Computational Study of the Polymerization‐Induced Phase Separation Phenomenon in Polymer Solutions under a Temperature Gradient

“…Examples of polymeric materials with anisotropic morphologies include anisotropic porous polymer membranes and switchable holographic PDLC films. [15,16] The structural anisotropy can be introduced by imposing an external fluctuation, such as an electric field, [17,18] a shear flow, [19] a concentration gradient, [15] a temperature gradient [20][21][22] or controlled chemical reaction [23][24][25][26] to the phase-separating polymeric systems. The PIPS method will be studied in this paper, for fabricating anisotropic polymeric materials by means of applying an external temperature gradient to the polymer solution.…”

Phase-separation dynamics of a ternary mixture coupled with reversible chemical reaction

“…Experimentally, phase separation of binary polymer blends under photo-cross-linking reaction has been extensively investigated by Tran-Cong and fascinating patterns are observed in his studies. [11][12][13][14] Over the last several decades, a few theoretical studies have investigated the spinodal decomposition coupled with chemical reaction. Huberman pioneered in this field and examined the effects of chemical reaction upon spinodal decomposition.…”