Molecule-based electrorheological material, rare earth complex of β-cyclodextrin inclusion compound

Molecule-based electrorheological (ER) materials, based on β-cyclodextrin (β-CD) inclusion compounds between β-CD (host) and acrylic acid [HA, guest] or the rare earth (RE = Y) complex [YA3, guest] of acrylic acid have been synthesized as a novel type of ER materials. The composition, ER performance and dielectric property of the materials have been studied. The results show that the formation of the rare earth complex can markedly enhance the ER performance of β-CD, and HA cannot. The relative shear stress τr (τr = τE/τ0, τE and τ0 are the shear stresses at the electric field strength E = 4.2 and 0 kV/mm, respectively) of the suspension (25 wt%) of a complex material in silicone oil reached 1297 at a shear rate of 14.3 s−1, such large τr value is advantageous in its application as an ER material. The composition and structure are the dominant factors in improving the ER effect.