Self‐assembling structure formation in low‐density magnetoactive polymers

The formation of microstructures in magnetoactive polymers (MAPs) is a recently discovered phenomenon found only with very low filler particle concentrations (less than 3 wt %). Due to the degassing process, filler particles collect around an ascending bubble, which dissolves at a certain point leaving particulate rings within the matrix. The formation of toroidal microstructures commences as filler concentration approaches 1 wt %. The development of coherent parallel aligned rings with a compact order continues as particle concentrations increase toward 2 wt %. Between 2 and 3 wt % capillary doublets develop, while mass percentages higher than 3% result in increasing entropy as the random order of particle agglomeration found in higher concentration MAP dominates. Self‐structured samples of different filler material and concentrations between 1 and 3 wt % have been investigated using X‐ray tomography, where the emerging structures can be observed and visualized. The ring structures resulting from this research represent microinductivities which can be fabricated in a targeted manner, thus enabling new applications in the high‐frequency radio field. Furthermore, these anisotropic, but well‐organized, structures have magnetic field‐dependent implications for optical, thermal, acoustic, and medical applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48291.