Superior elastomeric nanocomposites with electrospun nanofibers and nanoparticles of CoFe2O4 for magnetorheological applications

摘要: We show for the first time greatly enhanced magnetic and magnetorheological (MR) properties of CoFe2O4–silicone elastomer (cross-linked polydimethylsiloxane) composites containing electrospun CoFe2O4 nanofibers. The effects particle shape (spherical to fibrous), concentration degree alignment in elastomeric matrix are explored. Low nanofiber loadings (5–10 wt%) give MR comparable those obtained by much higher microparticle additions (60–80 same polymer matrix. Compared spherical nanoparticles, have 100–400% improvement that vital tunable rheology applications such as vibration damping, variable stiffness devices, actuators, etc. nanofibers effectively formed an interconnected network within but nanoparticles exhibited large gaps between two disconnected short chains at lower filler loading. Spherical particles with 69.46 emu g−1 saturation magnetization were synthesized ultrasonic assisted co-precipitation method using a novel precipitating solvent (i.e. propylamine) followed calcination. prepared electrospinning precursor sacrificial solution polyvinylpyrrolydone (PVP) calcination fibers. Crystal structure nanofillers evaluated X-ray diffraction (XRD), transmission electron microscopy (TEM) vibrating sample magnetometery (VSM), which showed generation larger crystallite size greater coercivity remnant compared nanoparticles. Thin films nanocomposites 5 10 wt% CoFe2O4. Anisotropic characteristics generated applying situ field 0.4 T during casting thin composite films. study revealed 1.023 T, isotropic absolute relative 4.4 kPa 3.21%, respectively, corresponding nanoparticle counterpart's values 2.0 0.64%.