Synergistic Effects of Surfactant on Dielectric and Electrorheological Properties of Boronic Acid Derivative Polymer Dispersions

Electric field stimulus fluids are prepared by dispersing poly(3-aminophenylboronic acid, PABA) and poly(thiophene-3-boronic acid, PTBA) nanoparticles in silicone oil (SO). Upon addition of a nonionic surfactant, Triton X-100, to the fluids, enhanced polarizabilities are detected on dielectric analysis which is driven by the increased number of dipole centers in their structures. Very high colloidal stability is observed for PABA/SO/Triton-X dispersion system since it has zeta(zeta)-potential value in colloidally stable region, whereas PTBA/SO/Triton-X dispersion system exhibits some degree of sedimentation due to low zeta-potential value. When electric field strengths are applied, increased yield stresses of the dispersions are detected. Storage and loss moduli values of PABA/SO/Triton-X and PTBA/SO/Triton-X dispersions suggest that the suspensions have vibration damping capabilities. Further, reversible non-Newtonian viscoelastic deformations are observed from the creep-recovery tests of the systems and they are classified as smart materials. Furthermore, the results show that PABA based colloidal system has better dielectric and rheological properties than that of PTBA and these results are also discussed in terms of particle conductivity and molecular structure.