Deformation studies of cylindrical nanostructured silica aerogels by using phase shifting digital holographic interferometry

Abstract In this paper, we have studied the deformation of cylindrical nanostructured silica aerogels prepared with methyltrimithoxysilane (MTMS) precursor. Two beam phase-shifting digital holographic interferometry (PSDHI) is applied along with a two-beam illumination technique to study in-plane displacements. To obtain the aerogels with different densities, the MeOH/MTMS molar ratio was systematically increased from the value 20 to 26. The cylindrical aerogels are loaded with various loads from the top surface. Phase shifted holograms of silica aerogels with varying densities, with and without deformation, are recorded with two beam illumination by CCD camera. Fresnel Diffraction integral is used to reconstruct the complex amplitude of aerogel samples. For in-plane displacements, phase distribution in deformed aerogels is determined by measuring the change in the two-phase distributions. The patterns corresponding to the phase distribution of aerogels for different loads and densities are recorded. It has been observed that the deformation of silica aerogels reduces by the value 0.02058 cm to 0.0017 cm, with an increase in bulk density 0.01742 gm/cc to 0.1952 gm/cc. The elastic behavior of aerogels has been explained under various loads by considering the phase distribution patterns and condensation reaction.