Influence of solvents on properties of monolithic La-based aerogels

La-based aerogels were synthesized by using LaCl37H2O as precursor, methanol and ethanol as solvents, via sol-gel process. The microstructure, components, specific surface area, pore diameter distribution and mechanical properties were characterized by scanning electron microscopy, Fourier transform infrared spectrometer, adsorption/desorption analysis and mechanical property tester, respectively. The results reveals that La-based aerogels derived from methanol and ethanol have a three-dimension network that consists of interconnected bead-like particles with diameters varying from several tens to hundreds nanometer. Comparing to the aerogel (specific surface area: 95 m2g-1, density: about 350 mgcm-3) derived from methanol, the aerogel (specific surface area: 220 m2g-1, density: about 160 mgcm-3) derived from ethanol possesses better pore morphology and worse mechanical property. The properties of the La-based aerogels can be attributed to the stronger polarity of methanol.