Yh. Lee et al., Synthesis and electrorheological characteristics of microencapsulated polyaniline particles with melamine-formaldehyde resins, POLYMER, 42(19), 2001, pp. 8277-8283
Polyaniline particles with low pH cannot be directly used in the electrorhe
ological (ER) systems, since their emerald base form has a conductivity tha
t is too high. Therefore, the pH of the polyaniline has been controlled to
yield a lower conductivity. To improve the particle preparation method for
polyaniline, which generates ER fluids with its semi-conducting characteris
tics, we synthesized microencapsulated polyaniline particles with melamine-
formaldehyde (MF) resins. Microcapsules, containing polyaniline with a low
pH as the core material, were prepared by polymerization of MF resin, which
play the role of an insulator between the polyaniline particles. From theo
logical measurements, the yield stress of the ER fluid decreased with the i
ncrease of MF resin, and this effect enhanced as the applied electric field
strength increased. (C) 2001 Published by Elsevier Science Ltd.