SYNTHESIS AND ELECTRORHEOLOGICAL CHARACTERIZATION OF POLYANILINE AND NA⁺-MONTMORILLONITE CLAY NANOCOMPOSITE

Abstract

Polyaniline-Na + -montmorillonite nanocomposite particles were synthesized using an emulsion intercalation method, and electrorheological (ER) fluids were produced by dispersing the synthesized nanocomposite particles in an electrically-insulating silicone oil. The emulsion of an aniline monomer with dodecyl benzenesulfonic acid was inserted into the layers of clay, and polymerization was processed by adding the oxidant initiator solution. DBSA as a emulsifier and a dopant took a important role for polyaniline clay nanocomposite. This insertion of polyaniline was confirmed by Xray diffraction. To observe its ER properties, we measured the shear viscosity and the shear stress by controlling shear rate. Furthermore, we conducted dynamic tests to investigate the viscoelastic properties of the ER fluid under an electric field in the linear viscoelastic region.

A Water Dispersible Nanocomposite of Polyacrylonitrile with Silica via Aqueous Polymerization of Acrylonitrile by K2CrO4–NaAsO2 Redox System

“…However, in presence of nanodimensional SiO 2 particles suspended in the aqueous medium the separated PAN particles encapsulated the SiO 2 particles and thereby formed the composite which remained suspended in the aqueous medium. This process was widely followed by previous workers [4][5][6][7][8][9][11][12][13][14][15][16][17][18][19][20][21][22][23][24] for the preparation of processable dispersions of intractable speciality polymers. The method presented here is expected to be of wide scope since these studies can be extended to miscellaneous water insoluble fundamental polymers including vinyl polymers as well as copolymers of these polymers with the speciality polymers like PPY, PANI, or PTP.…”

“…A significant recent development in this direction was the application of emulsion polymerization technique by Choi et al [21][22][23][24] for the formation of nanocomposites of both speciality polymers (PANI, PPY) and the fundamental polymers (polystyrene, polyacrylonitrile, and copolymers thereof) with Na + -MMT clay. Inverted emulsion pathway was recently described by Choi et al 25 for the preparation of intercalated PPY/Na + -MMT nanocomposite.…”

“…TG analyses revealed the enhanced thermal stability of the polyacrylonitrile-SiO 2 nanocomposite relative to that of the base polymer polyacrylonitrile. 20 developed a suspension polymerization technique using combination of water and appropriate nonaqueous solvents (for the monomers) in presence of usual oxidants to produce the corresponding nanocomposites.A significant recent development in this direction was the application of emulsion polymerization technique by Choi et al [21][22][23][24] for the formation of nanocomposites of both speciality polymers (PANI, PPY) and the fundamental polymers (polystyrene, polyacrylonitrile, and copolymers thereof) with Na + -MMT clay. Inverted emulsion pathway was recently described by Choi et al 25 for the preparation of intercalated PPY/Na + -MMT nanocomposite.…”

Synthesis and Rheology of Intercalated Polystyrene/Na+-Montmorillonite Nanocomposites

“…[8][9][10] These improved properties depend on the nanostructural configuration and interfacial bonding between the clay and the polymer. [11,12] Recently, polymer/clay nanocomposites with polyaniline [13,14] and styrene/acrylonitrile copolymer [15] have been introduced as candidate materials for drybase electrorheological (ER) fluids. In ER applications, [16,17] the rheological properties of dispersed polarizable colloidal suspensions under external electric field strength change abruptly via structural changes in the particle aggregation in either chain-or column-like structures.…”

Stimuli-Responsive Polymers and Colloids under Electric and Magnetic Fields

“…As shown in Figure 8, once the shear stress is applied, instantaneous strain appears and increases as a function of time until it approaches a maximum. The ER fluid becomes more solid-like (i.e., γmax,2 << γmax,1) under a higher electric field strength [88]. …”