| Considering the influence of dielectric constant, conductivity, and dielectric loss on electrorheological (ER) effects, an effective approach to prepare supramolecular complex ER materials was proposed by self-assembly. The significant preponderance of the host-guest complex formation is that the host structure can be easily controlled by two ways. The one way is the host structure can be changed under the different synthesis condition. The other is that the suitable guest can be selected according to the different molecular structure. Based on this point, our aim to obtain the high performance materials should be carried out as well as the ER behavior be actualized through the chemistry design.In this paper, 4 supramolecular complexes of β-cyclodextrin inhydrosoluble polymer/ l-(2-pyridlazo)-2-naphthol, 6 hydrosoluble β-cyclodextrin polymer/3-hydroxy-2-naphthoic acid, 2 β-cyclodextrin-starch resins and 6 supramolecular complexes of β-cyclodextrin-starch copolymer/substituted salisylic acid and 3-hydroxy-2-naphthoic acid ER particles were prepared, respectively. The structure of these particles was characterized by IR, NMR, UV-vis, the fluorescence analysis, element analysis, and etc, respectively. Then the electrorheological properties of the suspensions of these particles in silicone oil have been investigated under DC electric fields. The experimental results are given as follows:1. The supramolecular complexes of β-cyclodextrin cross-linking polymer/l-(2-pyridlazo)-2-naphthol ER particles were synthesized by self-assembly. The structure of the supramolecular complex was characterized by the fluorescence analysis, IR spectrometry and Chem3D simulation, respectively. The results confirmed that the naphthalene ring of the guest is included in the cavity of β-cyclodextrin cross-linking polymer. It was found that the electrorheological properties, the dielectric properties, the temperature dependence and the sedimentation stability of the typical supramolecular complex ER fluids were much higher than that of pure β-cyclodextrin polymer. Furthermore, the ER behaviors can be regularly affected by the cross-linked degree of the supramolecular complex. The results indicated that the suitable range of cross-linked degree was 4-8.2. In order to deeply probe into the influence of crosslinked degree on ER properties and expediently characterize the structure of the supramolecular complex, six hydrosoluble β-cyclodextrin polymer/3-hydroxy-2-naphthoic acid ER particles were synthesized. Fluorescence analysis conformed that all the polymers can form 1:1 type supramolecular complex with the guest. The results showed that the forming constant and the fluorescence relative intensity were increased with the increase of cross-linked degree, and also, a well straight line of △I vs. cross-linked degree was obtained (where △I = I - I0, I is the fluorescence relative intensity of guest in the presence of different β-cyclodextrin polymer and I0 is that of guest in aqueous solution).The electrorheological properties of suspensions of these particles in silicon oil have been investigated under DC electric field, which exhibited a significant ER behavior. The yield stress of them was 3.38-5.98 kPa at 3 kV/mm and 47.6% higher than that of pure β-cyclodextrin polymers. Meanwhile, the cross-linked degree of the polymer has strong influence on the supramolecular complex ER behavior.The results indicated that the suitable range of cross-linked degree was 6-8.3. Considering the shortcomings of hydrosoluble β-cyclodextrin polymer, such as easily water-absorbed properties and poor endurance in a high electric field, two β-cyclodextrin-starch resin electrorheological particles (WSS-β-CDP and CLS-β-CDP) were synthesized by copolymerization through a mixture of β-cyclodextrin and epichlorohydrin in the presence of water-soluble and water-insoluble starch, respectively. The structures of these polymers were characterized by FT-IR and Raman s...
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