Formation of highly ordered micro fillers in polymeric matrix by electro-field-assisted aligning

Abstract

Nanocomposites composed by polymeric matrix with micro/nano fillers have drawn lots of attention since their dramatic properties beyond pristine polymers. The spatial distribution of the micro/nano fillers in the polymeric matrix determines the final desired properties of the nanocomposites, thus deserves to investigate. Here, we proposed an effective method of assembling the micro/nano fillers to pre-designed patterns within the polymeric matrix by AC-electro-field-assisted aligning. By pre-designed AC electric fields which could be dynamically controllable, the distribution of microparticles (acting as fillers) in the matrix was tuned to various patterns related to the electric fields, such as linear alignment and circular alignment. The field-oriented particles chains could act as endoskeletal structures, showing unique properties (i.e., mechanical, optical, and anisotropic properties) beyond those of the conventional composites with randomly distributed particles.

Fig. 1. PS particles are assembled and patterned by AC electric fields within the polymeric matrix.

Fig. 2. (a) The PS particles dispersion in the sealed chamber device; (b) PS particles instantaneously formed chains under n-DEP force; (c) UV light irradiation was provided to the solution to allow photochemical polymerization; (d) the cured matrix was separated from the sealed chamber device by removing surrounding structures.

Fig. 3. (a and b) Field intensity distribution in the horizontal and vertical planes of (a) interdigital electrodes (b) serpentine electrodes; (c and d) curves of the absolute voltage value of (c) interdigital electrodes (d) serpentine electrodes; (e and f) simulation results of particles dynamic distribution of (e) interdigital electrodes (f) serpentine electrodes.

Fig. 4. (a and b) The LSCM pictures of (a) interdigital electrodes (b) serpentine electrodes; (c and d) the SEM pictures of (c) interdigital electrodes (b) serpentine electrodes; (e) the AFM picture; (f) the numerical curve of the surface roughness.

Fig. 5. (a and b) The chains formed by PS particles on (a) interdigital electrodes (b) serpentine electrodes; (c) the variation of the spacing of particles versus concentration; (d) the variation of the width versus concentration; (e) the change process of particles distribution.

Fig. 6. (a) The distribution of particles in the vertical plane; (b) the height variation with the kinematic viscosity at different applied voltages.