Electrorheological performances of poly(o-toluidine) and p-toluenesulfonic acid doped poly(o-toluidine) suspensions

Abstract

Poly(o-toluidine) (POT) and p-toluenesulfonic acid doped poly(o-toluidine) (TSA-POT) were synthesized via chemical oxidation and emulsion polymerization, respectively. The rheological measurements of the dedoped POT and TSA-POT silicone oil suspensions showed that both of the suspensions exhibited electrorheological (ER) effect under electric field. The analyses of the rheological curves of suspension indicated that POT and TSA-POT suspensions presented different flow behaviors. POT suspensions presented fast polarization under external electric field with the existence of critical shear rates (γ crit ), and POT suspensions behaved well with Bingham model above γ crit TSA-POT suspension behaved very well with Cho-Choi-Jhon model in all shear rate regions. Both of static and dynamic yield stresses for POT and TSA-POT suspensions in electric field were proportional to the square of electric field strength. The different ER performances between POT and TSA-POT suspensions were explained based on the conductivity and dielectric constant of the particles. The modification of conductivity and dielectric constant by doping POT with TSA improved the ER performance of TSA-POT suspension.

Preparation of core–shell structured metal–organic framework@PANI nanocomposite and its electrorheological properties

“…And when the ER uid is displayed a polarization model, its slope is 2. 48,49 Aer a linear tting calculation, the MIL-125@PANI-based ER uid meets the power-law relationship with an exponent of 1.4, which is very close to the conductivity model. The value of a is related to particle concentration, particle shape, particle composition, temperature and applied electric eld strength, etc.…”

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

“…Therefore, the ER suspension becomes a solid-like phase, exhibiting different rheological behaviors compared to a liquid-like ER suspension without an external electrical field. The changes in rheological properties include an increased shear viscosity, appearance of yield stress and increased dynamic modulus, where the ER fluid is similar to Bingham plastics [5,6]. In particular, chain-like structures are released as the electrical field is removed, allowing the ER suspension to recover to a liquid-like phase [7].…”

Emulsion‐polymerized polyindole nanoparticles and their electrorheology

“…When an electric field is applied, fine particles suspended in the insulating liquid construct a fibril structure along the direction of the applied electric field. The resultant dispersed particle structure permits investigation of its rheological properties such as shear stress, shear viscosity, and viscoelasticity change with an external electric field . The phase transition of ER fluids from a fluid‐like form to a solid‐like form is controllable and reversible on the order of milliseconds, allowing their use in wide range of electromechanical engineering applications, including torque components in rehabilitation devices, damper system, biomicro‐fluidic chips, and tactile displays …”

“…The resultant dispersed particle structure permits investigation of its rheological properties such as shear stress, shear viscosity, and viscoelasticity change with an external electric field. 2,3 The phase transition of ER fluids from a fluidlike form to a solid-like form is controllable and reversible on the order of milliseconds, allowing their use in wide range of electromechanical engineering applications, including torque components in rehabilitation devices, 4 damper system, 5 biomicro-fluidic chips, and tactile displays. 6 To expand the potential scope of ER fluids, a variety of materials such as inorganic/organic polymers and conducting polymers and their composites have been introduced as ER materials.…”