Title of article :
Rapid synthesis of water-glass based aerogels by in situ
surface modification of the hydrogels
Author/Authors :
Sharad D. Bhagat، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2007
Abstract :
The objective of the present research was to reduce the processing time of water-glass based aerogels synthesized via an ambient pressure
drying. For this purpose we employed a co-precursor method for the surface modification in hydrogels using trimethylchlorosilane (TMCS) and
hexamethyldisilazane (HMDS). The surface modification resulted in the displacement of pore water from the hydrogels and thereby absolutely
avoiding the time-consuming solvent exchange step. The attachment of trymethylsilyl (–Si(CH3)3) groups to the silica surface was confirmed by
the presence of Si–CH3 peaks at 2900, 1400, 1255 and 845 cm 1 in the Fourier Transform Infrared (FTIR) spectra. The differential thermal
analysis (DTA) revealed that the aerogels maintain their hydrophobic behavior up to a maximum temperature of 500 8C above which they become
hydrophilic. The physical and textural properties of the silica aerogels have been reported and the results have been discussed by taking into
account the surface modification and the amounts of the pore water displaced out from the hydrogels.
Keywords :
Silica aerogel , Water-glass , Surface modification , FE-SEM , FTIR , DTA , BET analysis
Journal title :
Applied Surface Science
Journal title :
Applied Surface Science