Preparation and properties of dispersions of colloidal boehmite rods
Dispersions of colloidal boehmite (γ-AlOOH) rods (of controllable length) are prepared from alkoxide precursors. A polyisobutene grafting procedure leads to sterically stabilized dispersions. In the organophilic system (L ≈ 200 nm ± 50%; D ≈ 10 nm ± 25%) an isotropic-nematic phase separation is observed for boehmite volume fractions between 3.8% and 14.6%. The effect of polydispersity on the phase diagram is well predicted qualitatively by Onsager’s theory extended to bidisperse mixtures.
Key wordsBoehmite rods organophilic isotropic-nematic phase separation
- 5.Fraden S, Hurd AJ, Meyer RB, Cahoon M, Caspar DLD (1985) J Physique 46:C3–85–C3–113Google Scholar