Electrokinetic, electrorheological and viscoelastic properties of Polythiophene-graft-Chitosan copolymer particles


Cabuk M. , YAVUZ M. , Unal H. I.

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, cilt.510, ss.231-238, 2016 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 510
  • Basım Tarihi: 2016
  • Doi Numarası: 10.1016/j.colsurfa.2016.06.014
  • Dergi Adı: COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
  • Sayfa Sayıları: ss.231-238

Özet

Electrokinetic properties of Polythiophene-graft-Chitosan (PT-g-CS) copolymer were investigated by means of zeta (zeta)-potential measurements as a function of pH, electrolytes, surfactants, and temperature in aqueous medium. The c-Potential of pure PT was observed to enhance from +25 mV to +36 mV after grating with polycationic CS. Concomitantly, the isoelectric point of the pure PT shifted from 6.4 to 8.3. The zeta-Potential of PT-g-CS dispersion also shifted to more positive regions with increasing valency of the electrolytes and concentrations of cationic surfactant (cetyltrimethylammonium bromide). The c-Potential of PT-g-CS was determined to be +38 mV which indicated colloidal stability in silicone oil (SO) medium. Electrorheological (ER) and viscoelastic measurements revealed that the PT-g-CS/SO system has elasto-viscous behavior under applied electric field strengths. The yield stress of the ER fluid was determined to be a function of the electric field strength in a power law form as tau(y) = E-1.55 which obey to the conduction model. Creep and creep-recovery tests revealed reversible non-linear viscoelastic deformations of %31<%40<%43 under E=1; 2 and 3 kV/mm conditions. (C) 2016 Elsevier B.V. All rights reserved.