Membranes have found applications in a wide range of industries including food, water treatment and biomedical applications. Improved separation characteristics and performance of these membranes is desired to increase the service life and types of separations which can be performed. In this work our aim is to incorporateTiO₂ into linear polyamide (Nylon-6) asymmetric membranes derived from acidified dipolar aprotic solvents. Most prior work has focussed on aromatic polymers, including polysulfones, that are soluble in dipolar aprotic solvents. A challenge in our work is to combine wet sol-gel chemistry with membranes formed from highly acidic 'dopes'. Low concentrations of TiO₂ may improve the mechanical characteristics and impart some antibacterial properties on the membrane. Membranes were prepared with up to 10wt.% TiO₂ as determined by thermogravimetric analysis (TGA). The properties of the membranes were characterised using dynamic mechanical analysis, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM).
Melting peaks of filled membranes increased with increasing TiO₂content. The presence of TiO₂ is not only shown by residues after TGA but also by FTIR where the 645.5cm^-1 peak is diagnostic. Increasing pore size was evident in the SEM micrographs as TiO₂ content increased. This may be attributed to changes in concentration and pH which affect the kinetics of solvent/non-solvent ingress/egress.