Electrorheological Effect of Chitosan Salts as the Dispersed Phases

Abstract

The electrorheological(ER) efects pertaining to the ER behavior of chitosan salts, chitosan, chitosan ammonium salt andchitosan phosphate suspensions in silicone oil were investigated. Chitosan salt suspensions showed a typical ER response(Bingham flow behavior) upon the application of an electric field. However, chitosan phosphate suspension exhibited anexcelent shear yield stress compared with chitosan and chitosan ammonium salt suspensions. The diference in behavior resultsfrom the difference in the conductivity of the disperse phases for thechitosan, chitosan amonium salt and chitosan phosphate suspensions exhibited a linear dependence on the volume fraction ofparticles, and power law dependence on electric field with power indices of 1.18, 1.41 and 1.67 respectively. On the basis of theexperimental results, the newly synthesized chitosan salt suspensions were found to be an ER fluid.