TY - JOUR
T1 - Reduction in the processing time of doped sodium silicate based ambient pressure dried aerogels using shaker
AU - Rao, A. Venkateswara
AU - Bangi, Uzma K.H.
AU - Kavale, Mahendra S.
AU - Imai, Hiroaki
AU - Hirashima, H.
N1 - Funding Information:
The authors are grateful to the Departments of Science and Technology (DST), New Delhi, Government of India, for the financial support for this work through a major research project on “Aerogels” (No. SR/S2/CMR-67/2006). One of the authors Uzma K.H. Bangi is highly grateful to DST for providing the Senior Research Fellowship (SRF).
Copyright:
Copyright 2010 Elsevier B.V., All rights reserved.
PY - 2010/10
Y1 - 2010/10
N2 - The experimental results on the " reduction in the processing time of doped sodium silicate based ambient pressure dried aerogels using shaker" , are reported. Shaking the hydrogels in the shaker in presence of distilled water helps in the removal of sodium salt and reduces the processing time of the aerogels. In addition, doping the gels enormously helps in the improvement of strength and thermal insulation property of the aerogels. Hence, the present paper deals with the study of the effects of shaking speed and shaking period of the granular gels, and doping the gels with titanium dioxide powder (TiO2) on the physical properties of the aerogels. The aerogels have been characterized by bulk density, volume shrinkage (%), porosity (%) and thermal conductivity. The quantitative analysis of hydrophobicity was done by measuring the contact angle of water on the surface of aerogel. The microstructural and elemental analyses studies were carried out using transmission electron microscopy (TEM), energy dispersive analysis by X-ray (EDAX) and fourier transform infrared (FTIR) spectroscopy. The pore volume and surface area of the aerogels were measured using N2 adsorption-desorption BET surface analyzer. The thermal stability of the aerogels was checked by thermogravimetric and differential thermal analyses (TGA-DTA). Silica aerogels with low density ∼0.047g/cc and low thermal conductivity ∼0.057W/mK have been obtained by shaking the gels at the speed of 150RPM for 4h using the molar ratio of Na2SiO3:H2O:TiO2:Citric acid:TMCS at 1:146.67:6×10-5:0.54:9.46, respectively. The shaking of the wet gels in a shaker reduces the processing time of the aerogels from 4 to 2days. These aerogels can be used as thermal insulating materials in ovens, refrigerators and related systems.
AB - The experimental results on the " reduction in the processing time of doped sodium silicate based ambient pressure dried aerogels using shaker" , are reported. Shaking the hydrogels in the shaker in presence of distilled water helps in the removal of sodium salt and reduces the processing time of the aerogels. In addition, doping the gels enormously helps in the improvement of strength and thermal insulation property of the aerogels. Hence, the present paper deals with the study of the effects of shaking speed and shaking period of the granular gels, and doping the gels with titanium dioxide powder (TiO2) on the physical properties of the aerogels. The aerogels have been characterized by bulk density, volume shrinkage (%), porosity (%) and thermal conductivity. The quantitative analysis of hydrophobicity was done by measuring the contact angle of water on the surface of aerogel. The microstructural and elemental analyses studies were carried out using transmission electron microscopy (TEM), energy dispersive analysis by X-ray (EDAX) and fourier transform infrared (FTIR) spectroscopy. The pore volume and surface area of the aerogels were measured using N2 adsorption-desorption BET surface analyzer. The thermal stability of the aerogels was checked by thermogravimetric and differential thermal analyses (TGA-DTA). Silica aerogels with low density ∼0.047g/cc and low thermal conductivity ∼0.057W/mK have been obtained by shaking the gels at the speed of 150RPM for 4h using the molar ratio of Na2SiO3:H2O:TiO2:Citric acid:TMCS at 1:146.67:6×10-5:0.54:9.46, respectively. The shaking of the wet gels in a shaker reduces the processing time of the aerogels from 4 to 2days. These aerogels can be used as thermal insulating materials in ovens, refrigerators and related systems.
KW - Ambient pressure drying
KW - Doping
KW - Shaking
KW - Thermal insulating material
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U2 - 10.1016/j.micromeso.2010.05.013
DO - 10.1016/j.micromeso.2010.05.013
M3 - Article
AN - SCOPUS:77954383398
SN - 1387-1811
VL - 134
SP - 93
EP - 99
JO - Zeolites
JF - Zeolites
IS - 1-3
ER -