Kaolin Nano Intercalation Er Fluid Materials Preparation And Performance

Electrorheological(ER) fluids, composed of nonconducting or weakly conducting particles dispersed in an insulating liquid, undergo dramatic, reversible changes when exposed to an external electric field. Apparent suspension viscosities and shear stress can increase several orders of magnitude.The kaolinite-organic matter intercalation compound is a new material with properties both of kaolinite and organic matter. In this paper, we integrate properties of kaolinite, dimethylsulfoxide, and carboxylmethyl starch, proposing a novel way to improve electrorheological effect by intercalating. The experimental result are given as follows:1 Dimethyl sulfoxide/ kaolinite hybrids were synthesized using an direct intercalation method and characterized by XRD and FTIR. The result shows that DMSO were intercalated into the interlayer of kaolinite and basal spacing was swelled from 0.715nm to 1.110nm, so the kaolinite-organic matter intercalation compound was formed. The dielectric and rheological characteristics of ER fluid were measured. The experiment shows that in the electric fields of 3kV/mm when shear rate of 5s-1 was applied to the ERF the shear stress of DMSO/kaolinite hybrids ERF can be 600pa, which is 6 times than that of pure kaolinite ERF. In the meanwhile, the antisedimentation and stability of ERF is excellent. The intrinsic reason for enhancing the rheological property is the improvement of dielectric property of the intercalation hybrids.2 According to the analysis of SEM, FTIR and XRD, we can draw such conclusion: Intercalation of CMS into kaolinite has collapsed the layer construction of kaolinite, which makes the single layers dispersed in the bodies of CMS. Theexperimental results show that intercalation of CMS into kaolinite improves the electrorheological effect. For example, the static shear stress of kaolinite/CMS nanocomposites ERF is 3.6 times as large as that of the pure kaolinite ERF. Furthermore, we also found that the electrorheological effect has the close relationship with the amount of CMS. With the component rate of 1 :1, the synergetic effect is appeared greatly and the kaolinite/CMS ER fluid displays a notable ER effect under DC current field. The test for dielectric and conduction properties shows that intercalatiion has improved the dielectric constant and electric conductivity of nanocomposites ERF. Dielectric constant is 2.07 times as large as that of pure kaolinite ERF, 1.78 times as large as that of CMS ERF; electric conductivity is 2.73 times as large as that of pure kaolinite ERF. These results can well explain the change of ER behaviors of kaolinite. On the basis of these analysis, we found a suitable explanation which can well reveal the increasing of dielectric properties and ER effect.Because the single layers which are collapsed by intercalating dispersed in the bodies of CMS, the nanocomposites ERF's operational temperature range has been broadened greatly(10-90c). Furthermore, the nanocomposites has a better sedimentation ratio because of the intercalation(sedimentation ratio=20% for 30 days).