Design and synthesis of barium ferrite-based nanocomposite films with highly regulated 3-D structures

Abstract

Technical control of filler distribution in polymer composites has been of great interest because the structural modulation of embedded filler assembly leads to superior property enhancement of the composites with reduced amounts of filler. However, sophisticated control technologies of fillers, including alignment, assembly, filler-to-filler connection and localization in polymer nanocomposites, still pose challenges. Herein, we introduce a facile electric field-oriented pin-point localization technique to regulate the distribution of inorganic fillers in composite film without surface modification of fillers. Distribution of nano powders with homogeneous dispersion in a per-polymer of polysiloxane is modulated by utilizing micromold electrodes with protruded surfaces under a DC electric field while curing the polymer. Analysis revealed that filament-like linear assemblies of nano particles were created in the hybrid films, and these assemblies were aligned perpendicular to the film plane. Comparing to setups where no voltage was applied, the flat electrode led to linear filler structures between the film surfaces and micromold electrodes, enabling precise arrangement of the linear assembly with strong intensity localized to the protrusions. The dependences of the alignment, linear structure generation, assembly localization on the microscopic mold, and the applied electric field strength are discussed.