Heterocoagulation method for preparation of composite fluoropolymer particles with core–shell structure for optimized electromagnetic performance

Tetrafluoroethylene-hexafluoropropylene copolymer (FEP) plays an important role in 5G communication era. Nevertheless, FeSiCr ferrite as inorganic particles were hardly incorporated in fluoropolymer phase. Heterocoagulation process represents an ideal solution making the inorganic particles disperse uniformly in the fluoropolymer phase. In this work, cetyltrimethylammonium bromide (CTAB) assumes a double-sided role in heterocoagulation for preparing C-FeSiCr@FEP5 with core–shell structure. Here, CTAB can not only make C-FeSiCr favorable dispersibility initially but also breaks FEP/C-FeSiCr-mixed dispersion system accelerating the heterocoagulation process. Due to the safeguard of FEP, natural resonance and eddy current loss as main attenuation mechanisms could be avoided for C-FeSiCr@FEP5 in the testing frequency range (1–18 GHz). The dielectric constant values of C-FeSiCr@FEP5 sample keep 2.11 from1.0 to 18.0 GHz with low dielectric loss, while their magnetic permeabilities are still above 1.00 with decreasing trend of magnetic loss at the same frequency range. C-FeSiCr@FEP5 composites with optimized electromagnetic performance are expected to have a broad range of applications in 5G communication, especially for miniature antenna.