Facile synthesis of large-sized monolithic methyltrimethoxysilane-based silica aerogel via ambient pressure drying

In this study, large-sized monolithic methyltrimethoxysilane-based silica aerogels were prepared via a facile sol-gel route using ambient pressure drying. The structural, morphological, and hydrophobic properties of the aerogels were characterized by scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller method, and contact angle. Thermal conductivity, thermal stability, and mechanical properties of the samples were also evaluated. The ambient pressure dried aerogels showed macro-pore structure and low density (as low as 75 kg m(-3)). The Young's modulus of the aerogels was observed to increase from 0.043 to 1.102 MPa with an increase in the density of the aerogels from 75 to 141 kg m(-3). Simultaneously, the aerogels exhibited superhydrophobicity (> 150A degrees), low thermal conductivity (0.036 W m(-1) K-1), and good thermal stability in air atmosphere. Both the simple fabricating process and the superior performance of the monolithic silica aerogel make it as a promising candidate for energy-saving sector. Large-sized monolithic methyltrimethoxysilane-based silica aerogel with superhydrophobicity was successfully prepared by a one-step sol-gel method via ambient pressure drying using methyltrimethoxysilane as precursor, distilled water as solvent, and ammonia as alkali catalyst. [GRAPHICS] .