Influence of ammonium salt of poly-methacrylic acid and butylamine addition on the viscosity and electrophoretic deposition behavior of ethanol-based powder suspensions

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Physicochemical and engineering aspects, 2005-10, Vol.267 (1), p.74-78
• Main Authors: Popa, A.M., Vleugels, J., Vermant, J., Biest, O. Van der
• Format: Article
• Language: English
• Subjects: Al 2O 3; Chemistry; Colloidal state and disperse state; Ethanol-based suspensions; Exact sciences and technology; General and physical chemistry; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Viscosity; Zeta potential; ZrO 2
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2005.06.038

Ethanol-based Al 2O 3 and Ce–ZrO 2 suspensions are stabilized with ammonium poly-methacrylate (Darvan-C) and n-butylamine. The effect of the additives on the suspension stability is studied by zeta potential and viscosity measurements. When n-butylamine is added to the particles dispersed in ethanol, the suspension is electrostatically stabilized, the viscosity decreases and a shear-thinning behavior is observed. The suspensions stabilized with Darvan-C have a low Newtonian viscosity at concentrations above 140 μl/g. The polyelectrolyte is a more efficient dispersant than the organic base due to electrosteric stabilization. When the suspension is stabilized with n-butylamine prior to Darvan-C addition, stable suspensions are obtained when the n-butylamine or Darvan-C concentration is kept low. The wet deposit obtained from the suspensions stabilized with different BA concentrations and more than 100 μl/g of Darvan-C deforms under its own weight. When Darvan-C is adsorbed on the particles prior to n-butylamine addition, the suspensions have a low viscosity and a Newtonian behavior and the wet EPD deposit is smooth and rigid.