Electrorheological Characteristics of Poly(diphenylamine)/magnetite Composite-Based Suspension

Abstract

Electro-responsive poly(diphenylamine)(PDPA)/Fe3O4 composite particles were prepared by the synthesis of PDPA particles using a chemical oxidative polymerization technique followed by loading nano-sized Fe3O4 particles onto PDPA via a chemical co-precipitation process. The morphological image of the PDPA/Fe3O4 particles was characterized by scanning electron microscope and transmission electron microscope. The crystalline structure was scrutinized by X-ray diffraction. The rheological characteristics of the suspension composed of PDPA/Fe3O4 particles suspended in silicone oil were investigated by a rotation rheometer, demonstrating standard electrorheological (ER) characteristics with a dramatic increase in shear stress and dynamic moduli under the application of an electrical field strength. The shear stress curves under an electrical field could be described using the Bingham model and the yield stress showed a power-law relationship with the electric field strength with an exponent of 1.5, following the conduction model. Furthermore, the frequency-dependent dielectric behaviors of the PDPA/Fe3O4 ER suspension was tested using an inductance (L)-capacitance (C)-resistance (R) (LCR) meter. The dielectric properties were well described using the Cole–Cole equation and were consistent with the results of the ER experiments.

Core–Shell Structured Magnetite-Poly(diphenylamine) Microspheres and Their Tunable Dual Response under Magnetic and Electric Fields

“…As shown in Figure (a), the diffraction peaks at 2θ = 30.24°, 35.62°, 43.08°, 53.68°, 57.21°, and 62.73° match well with the (220), (311), (400), (422), (511), and (440) planes of spinel Fe 3 O 4 , respectively . The other two peaks appear at 2θ = 20° (approximately) in the pattern of Fe 3 O 4 –PDPA shown in Figure (b), which corresponds to the crystalline structure of PDPA …”

Electrorheological and magnetorheological properties of liquid composites based on polypyrrole nanotubes/magnetite nanoparticles

“…The established understanding in the field is that the viscosity of biphasic liquids changes immediately when an electric field is applied, for the case of electrorheological suspensions [22,41], and respectively when a magnetic field is applied, for the case of magnetorheological suspensions [42]. The results obtained in figure 12 suggest that the CL obtained here has physical properties characteristic to electrorheological suspensions, and respectively to magnetorheological suspensions.…”

“…This exposure results in changes in viscosity and flow behavior, attributed to the alignment of polarized particles within the material. Examples of this phenomenon include poly(diphenylamine)/magnetite composite-based suspensions [22], smart fluids utilizing TiO 2 particles [23], and electrorheological fluids in general [24]. These properties are crucial in applications that demand precise control of fluid dynamics under electrical stimulation.…”

Nanoparticles Functionalized by Conducting Polymers and Their Electrorheological and Magnetorheological Applications

“…As another potential conducting polymer, poly(diphenylamine) (PDPA) has recently been employed as potential ER material owing to its excellent optical properties, environmental stability, ease of synthesis, and suitable electrical conductivity [99,100]. Kim et al [98] introduced PDPA as a As another potential conducting polymer, poly(diphenylamine) (PDPA) has recently been employed as potential ER material owing to its excellent optical properties, environmental stability, ease of synthesis, and suitable electrical conductivity [99,100]. Kim et al [98] introduced PDPA as a conducting polymer shell onto PS by π-π stacking interactions to fabricate a core-shell structured particle and adopted it as an ER material without de-doping.…”

“…Kim et al [98] introduced PDPA as a conducting polymer shell onto PS by π-π stacking interactions to fabricate a core-shell structured particle and adopted it as an ER material without de-doping. The particle size of PS and PS/PDPA was approximately 1 μm (Figure 5f,g), and the thickness of the thin PDPA layer calculated from As another potential conducting polymer, poly(diphenylamine) (PDPA) has recently been employed as potential ER material owing to its excellent optical properties, environmental stability, ease of synthesis, and suitable electrical conductivity [99,100]. Kim et al [98] introduced PDPA as a conducting polymer shell onto PS by π-π stacking interactions to fabricate a core-shell structured particle and adopted it as an ER material without de-doping.…”