Chatterjee, Minati and Naskar, Milan Kanti and Ganguli, Dibyendu (1999) Sol-emulsion-gel synthesis of shaped powders in the system BaO-TiO2. Journal of Sol-Gel Science and Technology, 16 (1-2). pp. 143-149. ISSN 0928-0707

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Shaped tetragonal barium titanate (BaTiO3) particles were prepared by the sol-emulsion-gel method with systematic variation of the concentration of a non-ionic surfactant in the organic phase (''oil phase'') of water-in-oil (w/o) emulsions above or below the critical micelle concentration (CMC). An acetate-based sol with equivalent oxide ratio BaO : TiO2 = 1 : 1 was selected for the study. Micelle formation of the surfactant and their self-aggregation apparently played an important role in controlling the shape and size of the droplets and accordingly shape and size of the final barium titanate particles resulting therefrom. Transmission electron microscopy (TEM) revealed that with low concentration of the surfactant (2-5 vol%) ill-formed spheres were obtained. Spherical particles were formed with increasing the surfactant concentration to 7 vol%. At 12 vol% of the surfactant, rod-like particles were first found to form, which with further increase in surfactant concentration to 15-20 vol%, gradually transformed to cube-like/lamellar type particles. Attempts have been made to explain the various particle shapes in terms of surfactant aggregation.

Item Type: Article
Uncontrolled Keywords: Barium titanate; sol-emulsion-gel; Surfactant; Micelle; critical micelle concentration (CMC)
Subjects: Engineering Materials
Divisions: Sol Gel
Depositing User: Bidhan Chaudhuri
Date Deposited: 18 Jun 2012 07:48
Last Modified: 18 Jun 2012 07:48

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