Microstructural evolution and kinetics of phase separation in binary polymer blends under electric fields

Abstract

Temporal evolution of microstructure and kinetics of phase separation under electric fields (E-fields) were numerically investigated for binary polymer blends at both off-critical and critical compositions, where the morphology, structure factor, characteristic size, and anisotropy parameter were adopted. The results show that the E-field can significantly influence morphological development and kinetic process of phase separation, and the influence rule at the off-critical composition is distinctly different from the rule at the critical composition. With the enhancement of E-field strength, the growth exponent in the x direction (perpendicular to the E-field) decreases and the growth exponent in the y direction (parallel to the E-field) increases. Moreover, as initial composition raises, anisotropy parameter firstly increases and then decreases, and reaches to a maximum at the critical composition. The simulation results were also compared with existing experimental results, and exhibit several different aspects. This study reveals the influence rule of E-fields on phase separation process of binary polymer blends. On the other hand, it can provide a scheme to predict and design anisotropic microstructures by E-fields, and further guide to produce polymeric composite materials with superior mechanical and physical properties.