Ma Huiru

Electrorheological properties of suspensions of PAn-PEO-PAn triblock copolymer particles

The PAn-PEO-PAn triblock copolymer with the PEG chain length of 400 was synthesized by chemical oxidation copolymerization of aniline and α, ω-bis(p-aminophenyl) poly(ethylene glycol) and characterized by FT-IR and TEM. The experimental results show that the copolymer particles are of a typical core-shell structure after the self-assembly process in water. Its conductivity is much lower than that of the pure PAn. The suspension containing 20 vol% PAn-PEO-PAn triblock copolymer in silicone oil exhibits a typical electrorheological (ER) effect in DC electric field, while it shows a lower leakage current density than that of the pure PAn-based ER fluids. Therefore, the PEO shell hinders the electric hop among PANI chains and decreases the current density of ER fluids in an external electric field, at the same time the interface polarity imprones the ER effects.

Smart property of homogeneous electrorheological fluid and its application in reducing seismic responses of engineering structures

The smart properties of homogeneous electrorheological fluid (HERF) containing side—chain type liquid crystalline polymer were studied and an actual HERF damper with an adjustable viscosity was produced. A mechanical model of the HERF smart damper was established on the basis of experiment and theoretical analysis. Then a controlled equation of SDOF structure by HERF damper was derived and a semi-active control strategy based on optimal sliding displacement of damper was presented. The simulation results for a single story frame structure indicate that HERF, which may avoid some defects of common particles-suspended ER fluids, is an excellent smart material with better stability. Using the semi-active control strategy presented, HERF smart damper controlled could effectively reduce seismic responses of structures and keeps the control stable at all times.