Electric field driven fractal growth dynamics in polymeric medium

• The paper is an extension of earlier work [Phys. Lett. A 376 (2012) 3604] on effect of electric field on DLA.
• Threshold value of electric field has been determined.
• Below the threshold, growth is random.
• Above the threshold, the growth is governed by diffusion, migration and convection.
• Different kinds of electrode geometries have been used to simulate the growth.

This paper reports the extension of earlier work (Dawar and Chandra, 2012) [27] by including the influence of low values of electric field on diffusion limited aggregation (DLA) patterns in polymer electrolyte composites. Subsequently, specified cut-off value of voltage has been determined. Below the cut-off voltage, the growth becomes direction independent (i.e., random) and gives rise to ramified DLA patterns while above the cut-off, growth is governed by diffusion, convection and migration. These three terms (i.e., diffusion, convection and migration) lead to structural transition that varies from dense branched morphology (DBM) to chain-like growth to dendritic growth, i.e., from high field region (A) to constant field region (B) to low field region (C), respectively. The paper further explores the growth under different kinds of electrode geometries (circular and square electrode geometry). A qualitative explanation for fractal growth phenomena at applied voltage based on Nernst–Planck equation has been proposed.