caa a22 4500 463224213 CHVBK 20180405153221.0 cr unu---uuuuu 170326e20070501xx s 000 0 eng 10.1007/s10853-006-1366-z doi (NATIONALLICENCE)springer-10.1007/s10853-006-1366-z Low density TEOS based silica aerogels using methanol solvent [Elektronische Daten] [Sharad Bhagat, Hiroshi Hirashima, A. Venkateswara Rao] Highly transparent monolithic silica aerogels based on the TEOS precursor were prepared by the two-step (acid-base) sol-gel process. The hydrolysis and condensation reactions of tetraethoxysilane (TEOS) proceeded in methanol solvent with oxalic acid and NH4OH as the catalysts, respectively. The wet gels were supercritically dried using methanol. The aerogels were characterized by transmission electron microscopy (TEM) and measurements of optical transmission, bulk density, volume shrinkage, porosity and thermal conductivity. Monolithic silica aerogels with high optical transmission (∼93%), low density (∼0.055g/cm3), low thermal conductivity (∼0.04W/mK), and minimum volume shrinkage (∼10%), were obtained for the molar ratio of TEOS:MeOH:acidic H2O:basic H2O at 1:33:3.5:3.5 alongwith the oxalic acid and NH4OH concentrations at 0.001M and 1M, respectively. Springer Science+Business Media, LLC, 2007 Bhagat Sharad Air Glass Laboratory, Department of Physics, Shivaji University, 416 004, Kolhapur, Maharashtra, India aut Hirashima Hiroshi Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, 223-8522, Kohoku-ku, Yokohama, Japan aut Venkateswara Rao A. Air Glass Laboratory, Department of Physics, Shivaji University, 416 004, Kolhapur, Maharashtra, India aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/9(2007-05-01), 3207-3214 0022-2461 42:9<3207 2007 42 10853 https://doi.org/10.1007/s10853-006-1366-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-1366-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bhagat Sharad Air Glass Laboratory, Department of Physics, Shivaji University, 416 004, Kolhapur, Maharashtra, India aut NATIONALLICENCE 700 1- Hirashima Hiroshi Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, 223-8522, Kohoku-ku, Yokohama, Japan aut NATIONALLICENCE 700 1- Venkateswara Rao A. Air Glass Laboratory, Department of Physics, Shivaji University, 416 004, Kolhapur, Maharashtra, India aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/9(2007-05-01), 3207-3214 0022-2461 42:9<3207 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer