Fabrication of B4C ultrafiltration membranes on SiC supports

The fabrication of B4C ultrafiltration membranes is described. Firstly, a semi-dilute B4C slurry was environmentally-friendly prepared by aqueous colloidal processing, optimizing its dispersion by sonication, and used to deposit B4C membranes onto SiC macro-porous supports by dip-coating. Secondly, the resulting green membranes were characterised microstructurally by scanning electron microscopy (SEM), and pressureless sintered within the intermediate sintering regime. Thirdly, the sintered membranes were calcined in air to clean them from possible free carbon in the smallest pores, with the optimal calcination conditions having been identified by thermogravimetry coupled with mass spectrometry. Next, the calcined, sintered membranes were characterised microstructurally by SEM, tested mechanically against scratching, and characterised texturally by capillary flow porometry, thus identifying the optimal among them. Lastly, as a complement to the fabrication study, the filtration permeability of the optimal membrane was evaluated using deionized water. This work thus paves the way towards the fabrication of ceramic membranes based on B4C, lighter and potentially more durable than others, for filtration applications.