Common to liquids, solids and substances in between the former two is that if a stress is applied to them, they will strain. Stress may be visualized by placing a small amount of fluid between two parallel plates. When one plate slides over the other, forces act on the fluid dependent upon the rate of the plate movement. This causes a shear stress on the liquid. Recall laminar flow of fluids through a tubular vessel. Strain is the response to the stress. If solids are elastic, they deform and return to their original shape. Since fluids are not elastic and, hence, viscous, their deformation is irreversible.

Introduction to rheology

Adsorption kinetics and mechanism of cationic methyl violet and methylene blue dyes onto sepiolite

Antibacterial and conductive injectable hydrogels based on quaternized chitosan-graft-polyaniline/oxidized dextran for tissue engineering

Isoelectric points and points of zero charge of metal (hydr)oxides: 50years after Parks' review.

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.

https://dspace.inha.ac.kr/bitstream/10505/1801/1/Electrorheology.pdf

Electrorheology of polymers and nanocomposites

Synthesis, characterization and antimicrobial activity of biodegradable conducting polypyrrole-graft-chitosan copolymer

This study covers the synthesis of conducting poly- indole (PIN) homopolymer, poly(vinyl chloride)/polyindole (PVC/ PIN) composites, and preparation of their freestanding films. PIN and composites were synthesized chemically by radicalic mechanism using FeCl3 as an initiator. Films of PVC and PVC/ PIN composites were prepared by casting on glass Petri dishes. Mechanical properties of films were examined by stress-strain experiments. From FTIR spectra of polymers, it was revealed that polymerization reaction occurred by 2-3 mechanism. The conductivities of polymers at different temperatures were also measured by four-probe technique and found in the range 10 � 4 to 10 � 5 Sc m � 1 . Magnetic properties of the polymers were ana- lyzed by Gouy scale measurements and were found that their conducting mechanisms are of polaron and bipolaron natures. Thermal properties of polymers were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) and found that they had shown adequate thermal stabil- ity. X-ray diffraction (XRD) spectra showed the amorphous na- ture of the polymers. Scanning electron microscopy (SEM) was used for microstructural analysis. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1290-1298, 2010

Preparation of conducting poly(vinyl chloride)/polyindole composites and freestanding films via chemical polymerization

Comparison of electrorheological properties of some polyaniline derivatives

Composites of a polyindole (PIN) and poly(vinyl acetate) (PVAc) were prepared chemically using FeCl3 as an oxidant agent in anhydrous media. The composite compositions were altered by varying the indole monomer during preparation. The composites were characterized by FTIR and UV‐visible spectroscopies, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), stress‐strain experiments and conductivity measurements. Moreover, the film of PVAc and PIN/PVAc composites were prepared by casting on glass Petri dishes to examine their stress‐strain properties. PIN/PVAc composites are thermally more stable than PIN. It was found that the conductivities of PIN/PVAc composites depend on the indole content in the composites.

Synthesis and Characterization of Polyindole/Poly(vinyl acetate) Conducting Composites

This study was to synthesize the inherently conductive polymer polyaniline using an optimized process to prepare polyaniline/silicon dioxide (PANI/SiO2) composites by in situ polymerization and ex
 situ solution mixing. PANI and PANI/SiO2 composite films were prepared by drop-by-drop and spin-coating methods. The morphology of particles and films were examined by a scanning electron microscope (SEM). SEM measurements indicated that the SiO2 were well-dispersed and isolated in composite films. The electrorheological (ER), characteristics of the PANI/SiO2 composites were investigated. A volume fraction series (φ = 5–25 %) of the PANI/SiO2/silicone oil dispersions were prepared and sedimentation stabilities were determined. An ER activity was observed from the samples, when subjected to external electric field strength thus, they were classified as smart materials. Some parameters affecting the ER properties of the dispersions such as volume fraction, shear rate, electric field strength, frequency, and temperature were investigated.

Halil Ibrahim Unal

Papers

Synthesis, characterization and antimicrobial activity of biodegradable conducting polypyrrole-graft-chitosan copolymer

Preparation of conducting poly(vinyl chloride)/polyindole composites and freestanding films via chemical polymerization

Comparison of electrorheological properties of some polyaniline derivatives

Synthesis and Characterization of Polyindole/Poly(vinyl acetate) Conducting Composites

Synthesis and electrorheological properties of polyaniline/silicon dioxide composites