Influence of Feedstock Particle Size on the Pore Size of Titanium Dioxide Ceramic Filtration Membranes Fabricated by Suspension Plasma Spray (SPS) Process

Porous ceramic filtration membranes with anisotropic microstructures are considered to be effective and eco-friendly tools for removing hazardous pollutants in many industries. Depending on the contaminants of concern, submicron to a few micron-sized pores are essential for this application. SPS process enables deposition of a few microns to nano-sized particles in a suspension to generate such a microstructure. Potential of SPS process for fabricating hybrid filtration/photocatalysis titanium dioxide ceramic membranes, where pores were generated as a result of presence of not-melted particles has previously been demonstrated by the authors. This study aims at investigating the influence of the powder particle size of the feedstock suspension on the pore size in porous ceramic membranes. Three aqueous suspensions of titanium dioxide powder with the mean particle sizes of 200 nm, 500 nm and 1 μm were used to prepare the suspensions. The influence of spray parameters on characteristics of the membranes was investigated. SEM and X-ray diffraction were used to characterize the microstructure and the crystalline composition of the membranes, respectively. Porosity evaluation was performed using gray-scale image analyzing method and mercury intrusion porosimetry. Permeability of the membranes was measured in a dead end stirred cell.