ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Improving physical properties of silica aerogel using compatible additives

Suhas D. Doke, C. M. Patel, and V. N. Lad

Department of Chemical Engineering, Sardar Vallabhbhai National Institute of Technology - Surat, Surat, India

E-mail: vnl@ched.svnit.ac.in

Received: 31 January 2020  Accepted: 6 July 2020

Abstract:

Many applications of silica aerogel require desired mechanical and structural properties. Glycerol and polyethylene glycol were used for the synthesis of silica aerogel to improve mechanical and structural properties. Methyltrimethoxysilane was used as a precursor in various concentrations to explore the effects on the properties of silica aerogel. Polyethylene glycol-based aerogel exhibited high tensile stress-withstanding capacity, at the same time high surface hydrophobicity with contact angle 148°. The swelling and de-swelling behavior of aerogel were also analyzed. This lightweight material has low bulk density, which is found to be affected by the presence of additives. The density of aerogel varied from 0.07 to 0.09 g/cm³ with increasing amount of additive. Polyethylene glycol is found to be very effective additive especially for the improvement of the mechanical properties of aerogel, as it has exhibited the breakdown at 21,924.6 N/m² with elongation of 0.8 cm. The aerogel samples were analyzed for their surface hydrophobicity and thermogravimetry analysis. The elemental analysis of aerogel confirmed the purity of aerogel while thermogravimetric analysis and differential thermogravimetric analysis revealed its high thermal stability up to 519 °C.

Graphical abstract

Keywords: Aerogel; Mechanical properties; Polyethylene glycol; Surface hydrophobicity; Swelling; Thermogravimetry analysis

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01281-4

Chemical Papers 75 (1) 215–225 (2021)