Polyaniline Coated Core-Shell Typed Stimuli-Responsive Microspheres and Their Electrorheology

Abstract

Functional core-shell-structured particles have attracted considerable attention recently. This paper reviews the synthetic methods and morphologies of various electro-stimuli responsive polyaniline (PANI)-coated core-shell-type microspheres, including PANI-coated Fe 3 O 4 , SiO 2 , Fe 2 O 3 , TiO 2 , poly(methyl methacrylate), poly(glycidyl methacrylate), and polystyrene along with their electrorheological (ER) characteristics when prepared by dispersing these particles in an insulating medium. In addition to the various rheological characteristics and their analysis, such as shear stress and yield stress of their ER fluids, this paper summarizes some of the mechanisms proposed for ER fluids to further understand the responses of ER fluids to an externally applied electric field.

Microfibrillated Cellulose Suspension and Its Electrorheology

“…where τ y is the yield stress obtained from a shear stress at a zero shear rate extrapolation, t 2 and t 3 are the time constants, and η ∞ is the high shear viscosity. Although α is designated to the shear stress decrease at a low shear rate regime, the constant β is located in a range of 0 < β ≤ 1, because dτ/dγ ≥ 0 [39]. A dynamic oscillation measurement of the MFC particle-based ER suspension was performed to estimate the linear viscoelastic (LVE) regime in the strain amplitude sweep study at a constant angular frequency of 1 Hz in the strain region from 0.001% to 100%, as shown in Figure 4.…”

Dual Electrorheological and Magnetorheological Behaviors of Poly(N-methyl aniline) Coated ZnFe2O4 Composite Particles

“…The dynamic obtained from the extremely low limit of the is expressed as a function of the input E in Figure 11 using a power-law equation (Equation (3)) [ 46 ]. Because the slope is approximately 1.5, in the ZnFe 2 O 4 /PMA case, the response implies the conduction mechanism [ 37 ]. …”

“…The de-doping process, which is an alkali treatment to lower the electrical conductivity of the PMA part of the synthesized particles by adjusting the pH, was performed using NaOH solution (1 M) at room temperature. The decreased conductivity of the particles could prevent the electrical short circuit during the ER test under the E [ 37 ]. The products were put in DI water, and sodium hydroxide solution was dropped until the pH reached 8, and the solution was then stirred continuously for 24 h. The final products were then magnetically separated and cleaned with DI water.…”

Smart pH-Responsive Polyaniline-Coated Hollow Polymethylmethacrylate Microspheres: A Potential pH Neutralizer for Water Purification Systems

“…Specific moieties can be grafted or coated on the polymer surface to improve polymer performances. , Surface functionalization of PMMA with metal oxides, nanoparticles, or different polymers leads to the development of smart materials for important industrial applications. , Several surface functionalization methods are available in the literature. Adequate design and synthesis of functional hollow microspheres can lead to the development of materials that can respond intelligently to changing temperature, electric fields and magnetic fields, pH and ionic strength, , and so on. Apart from these, the monodispersity of the hollow microspheres is also important in improving their material performances.…”

“…40,41 Several surface functionalization methods are available in the literature. Adequate design and synthesis of functional hollow microspheres can lead to the development of materials that can respond intelligently to changing temperature, 42 electric fields 43 and magnetic fields, 44 pH and ionic strength, 45,46 and so on. Apart from these, the monodispersity of the hollow microspheres is also important in improving their material performances.…”