Influence of various processing parameters on water-glass-based atmospheric pressure dried aerogels for liquid marble purpose

摘要

Experimental results on the influence of various processing parameters on water-glass-based atmospheric pressure dried aerogels for liquid marble purpose are reported. Silica aerogels were prepared by varying the parameters namely washing temperature of the gels with water, washing period of the gels, protic solvents, and drying method. The physical properties of silica aerogels were studied by measuring granular bulk density, contact angle with water, thermal conductivity, and thermal stability in the furnace. The elemental analyses were carried out using Atomic Absorption Spectroscopy (AAS) and FT-Raman spectroscopy. The structural studies were carried out using Transmission Electron Microscopy (TEM). Also, the effect of humidity on the silica aerogels was studied in humidity chamber. Opaque silica aerogels with hydrophobicity (150°), low density (0.053 g/cm3), and low thermal conductivity (0.068 W/mK) have been obtained for the molar ratio of Na₂SiO₃: H₂O: citric acid: TMCS at 1:146.67:0.72:9.46. The hydrophobic powder of silica aerogels can form the liquid marbles.