Preparation of high solid loading titania suspension in gelcasting using modified boiling rice extract (MBRE) as binder

Preparation of high solid loading homogeneous titania suspension using modified boiling rice extract (BRE) as consolidator (network-former)/binder for gelcasting application has been investigated. To achieve in situ consolidation forming of TiO2 ceramic, the gel network formed by swelling and gelatinization of the modified BRE (MBRE) with 2-hydroxyethylmethacrylate was studied. The dispersion behaviour of the titania powder and rheology of the suspension under the influence of binder content, dispersant (Darvan 821A) concentration and pH of the dispersing media have been discussed. The present process of gel casting deals with 50–80 weight% solid loading of titania particles with MBRE (2–10 weight% to that of total solid loading) in presence of dispersant (ammonium salt of polyacrylic acid [(C4H5O2–NH4+)n]). The influence of BRE concentration and solid particle loading on rheological properties of aqueous titania suspensions has been analyzed under steady and oscillatory shear conditions. Thermogravimetry (TG) and differential thermal analysis (DTA) on gelcast green body has been evaluated and analyzed. The characterization of green and sintered body has been done with respect to density, porosity and microstructure.