Titanate coupling agent effects on nonaqueous Co2Z ferrite suspensions dispersion

Co2Z ferrite powders with the chemical composition 3Ba0.5Sr0.5OÆ2CoOÆ12Fe2O3 have superior high frequency magnetic properties. However, Co2Z ferrite powders are difficult to apply to practical processes because of agglomeration induced by the strong magnetic attraction between particles. In this study, Co2Z ferrite powder pretreatment using a titanate coupling agent— Neopentyl (dially)oxy tri(dioctyl)pyrophosphate titanate (Lica 38) on the sedimentation and rheological behavior is investigated. The bonding mechanisms between ferrite powder, Lica 38, and dispersant (KD1) are studied using diffuse reflectance Fourier transform infrared spectroscopy is used to explain the difference in the rheological and sedimentation behaviors of untreated and titanate coupling agent-modified ferrite powders. The affinity of Co2Z ferrite and dispersants could be substantially enhanced by coating a titanate- coupling agent onto the ferrite surface. The coated layer could prevent particles from agglomerating from magnetic interaction.