EFFECT OF SONOCHEMICAL SYNTHESIZED TIO2 NANOPARTICLES AND COAGULATION BATH TEMPERATURE ON MORPHOLOGY, THERMAL STABILITY AND PURE WATER FLUX OF ASYMMETRIC CELLULOSE ACETATE NANOCOMPOSITE MEMBRANES PREPARED VIA PHASE INVERSION METHOD

In this study, asymmetric pure CA and CA/ TiO2 nanocomposite membranes were prepared via phase inversion by dispersing TiO2 nanoparticles in the CA casting solutions induced by immersion precipitation in water coagulation bath. TiO2 nanoparticles, which were synthesized by the sonochemical method, were added into the casting solution at different concentrations. Effects of TiO2 nanoparticles concentration (0, 5, 10, 15, 20 and 25 mass%) and coagulation bath temperature (CBT, 25, 50 and 75 degrees C) on morphology, thermal stability and pure water flux (PWF) of the prepared membranes were studied and discussed. Increasing TiO2 concentration in the casting solution film: along with higher CBT resulted in increasing the membrane thickness, water content (WC), membrane porosity and pure water flux (PWF). Also, these changes facilitate macrovoids formation. Thermal gravimetric analysis (TGA) shows that thermal stability of the nanocomposite membranes was improved by the addition of TiO2 nanoparticles. Furthermore, TGA results indicated that increasing CBT in each TiO2 concentration, leads to the decreasing of decomposition temperature (T-d) of nanocomposite membranes.