Electrorheology of polymers and nanocomposites

Abstract

This highlight aims to report electrorheological (ER) materials in state-of-the art polymeric particles and their various nanocomposites with clay, mesoporous inorganics and carbon nanotubes along with their potential application. ER fluids, suspensions of these particles having higher dielectric constant or electrical conductivity than the low-viscosity fluids in which they are suspended, are currently regarded as a smart/intelligent material, because their structural and rheological properties can be systematically tuned by controlling electric field strengths. In this highlight, various conducting polymers, including polyaniline, polypyrrole, poly(p-phenylene), poly(naphthalene quinone) and copolyaniline, are introduced and different types of polymer nanocomposites are emphasized. Flow curves for shear stress of the ER fluids are also examined.

Effect of Surface Roughness on the Stick-slip Behavior of Magnetic Field Controlled-dipolar Suspensions in Simple Linear Shear Mode

“…Research concerns more about the properties and mechanisms of the stick-slip motion due to the characterization of the materials and some focus on controlling and modulations [5,6]. Mechanical properties of electrorheological(ER) and magnetorheological (MR) fluids can be dramatically changed once exposed to the external electric/magnetic field [7,8]. This provides two controllable phases of one matter, the possibility in the modifying the energy consuming process.…”

Effect of Magnetic Nanoparticle Additive on Characteristics of Magnetorheological Fluid

“…However, under an external magnetic field, the particles interact through induced dipole-dipole interactions, MR fluids solidify into a solid-like paste immediately in the presence of a magnetic field (as particles form chain structures aligning along the direction of the magnetic field due to the magnetic-polarization interaction), and then re-liquify in the absence of the magnetic field. These whole processes are similar to that of electrorheological fluids under an applied electric field [9]- [11]. These changes are significantly fast within the order of millisecond and nearly reversible, which leads to various applications, ranging from active controllable dampers, torque transducers, to robotic and vibration control system [12], [13].…”

Complex Fluids in Energy Dissipating Systems

“…That microstructural transition, in which the particles form chains connecting the electrodes once the electric field is active, is reversible once the voltage is removed, as depicted in Figure 1. This fast, strong and reversible response allows the development of simple and efficient electromechanical systems able to control vibrations and dissipate energy in shocks [26,27]. However, the development of applications has been hindered due to the weakness of the Electrorheological effect (<10 kPa, much below 30 kPa required by many mechanical devices [28]) until the discovery of the giant electrorheological (GER) effect [29], which can reach a yield strength (>10 kPa [28]) above the theoretical upper bound on conventional ERFs.…”