| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 594946 | Colloids and Surfaces A: Physicochemical and Engineering Aspects | 2011 | 7 Pages |
Soft magnetic carbonyl iron (CI) based magnetorheological (MR) fluids containing three different loadings of submicron-sized organoclay were prepared. The MR characteristics were measured via rotational and oscillatory tests, in which the flow curves exhibited a non-Newtonian behaviour for all investigated samples. The dynamic yield stress change was measured as a function of magnetic field strength by adopting a linear fit of the relation of log (τy) proportional to log (H), which was originally applied for electrorheological fluids. The viscoelastic performances of the pure CI suspension and the CI/organoclay suspensions showed the existence of a solid-like character. The sedimentation ratio was also investigated to confirm the role of sub-micron organoclay particles on the MR properties, in which the dispersion stability of pure CI was improved with increasing the content of organoclay in the CI suspension.
Graphical abstract. Organoclay was successfully introduced in the Carbonyl iron suspension with improved dispersion stability and better fitting to universal yield stress equation.Figure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights▶ Organoclay was introduced in the CI suspension to improve sedimentation and dispersion stability of the MR fluid. Especially, the presence of submicron-sized C15A particles improved sedimentation stability. ▶ The correlation between dynamic yield stress and magnetic field strength for MR fluids was analyzed by a quoted universal yield stress equation which has been well adopted in the electrorheological fluids. ▶ The viscoelastic behaviour of the MR suspensions exhibited a solid-like character.
