Electrorheologically intelligent polyaniline and its composites

Abstract

Electrorheological (ER) fluids are generally composed of electrically polarizable inorganic or organic particles dispersed in insulating oils. These materials are intelligent/smart materials in that they are capable of changing their state from liquid-like to solid-like very quickly under an applied electric field. This feature article reviews the literature regarding the fabrication of conducting polyaniline (PANI) and PANI composite particles, their ER performance, as well as their chemical and physical characteristics of morphology and crystal structure. The ER behavior of these intelligent materials was also analyzed using a range of rheological equations of state and their dielectric properties.

Conducting polyaniline-wrapped sepiolite composite and its stimuli-response under applied electric fields

“…ε 0 is the dielectric constant at the frequency (ω) approaches 0, ε ∞ is the dielectric constant at the high frequency limit and ˛ is a constant for a given material, having a value of 0 ≤ ˛ ≤ 1 [49]. As the main parameters for the PANI/SPL based ER fluid, ε 0 and ε ∞ were 3.76 and 1.64, and the values of ˛ and were 0.724 and 1.65 × 10 −4 , respectively.…”

Effect of aliphatic spacer length on the electrorheological properties of side-chain liquid crystalline polymer-silica composite suspensions

“…[13][14][15][16][17][18][19] The conductivities of SCLCP-silica composite particles were measured as 2.19×10 -11 , 1.92×10 -11 , and 1.78×10 -11 S/cm for BP-6, BP-8, and BP-12, respectively; almost the same regardless of the aliphatic spacer length, but with the trend of conductivity decreasing with increasing aliphatic spacer length. The result shows that the spacer length between the polymethacrylate backbone and polar mesogenic groups influences the ER response.…”

“…Due to their fast response time and controllable shear viscosity, the ER fluids have been widely used for various engineering applications such as dampers, clutches and adaptive structures. 4,5 To solve the limitations of water based ER systems, such as thermal stability, poor durability and corrosion, anhydrous ER fluids using polymer particles, 10,11 inorganic-organic composite particles, 12 semiconducting polymer particles, 8,13 semiconducting polymer-nanocomposites, [14][15][16][17][18][19][20] and semiconducting polymer composites particles 7,21 were used for ER fluids and showed promising ER responses. SCLCPs have also been proposed for ER fluids to avoid the above limitations.…”

Physical characteristics of magnetorheological suspensions and their applications

“…In particular, magnetorheological (MR) suspensions [1][2][3][4][5][6][7][8][9][10][11][12], electrorheological (ER) fluids [13][14][15][16][17] under an applied electric field, magnetorheological elastomers [18][19][20][21][22], shape memory materials [23] and piezoelectric composites [24] are materials with controllable physical properties. The response function of the mechanical or electrical characteristics or combinations of these depends on the action of a field (magnetic or electric -according to whether the material has electrical or magnetic properties or combinations of these) [25].…”