Ceramics-Silikáty 63, (3) 305 - 314 (2019)

The goal of this study was to understand the effect of sintering temperature and duration on the morphology and mechanical properties of the La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ (LSCF) asymmetric flat membrane. The LSCF was prepared using the solid-state method and flat asymmetric membranes were prepared from LSCF powder using polyethersulfone (PESf) as the binder, dimethyl sulfoxide (DMSO) as the solvent and demineralized water as the coagulant (non-solvent). The membranes were sintered at 950, 1100, and 1250°C for 4 and 8 h to examine the effect of sintering temperature on the morphology, porosity, hardness and thermal expansion properties of the resulting membranes. Analysis of the results showed a slight difference in membrane density when employing a sintering duration of 4 and 8 h at the same temperature. Whilst sintering temperature was observed to significantly affect the morphology and mechanical properties of the asymmetric membrane. SEM images showed that all membranes retained their asymmetric structure with finger-like pores in their porous layer. Increasing the sintering temperature produced greater membrane density, where sintering at 1250°C produced the strongest membrane with the greatest density and hardness (412,36 Hv). The thermal expansion of the membranes was also measured by TMA, which demonstrated a low thermal expansion coefficient associated with the denser membranes.