Synthesis of high temperature resistant ZrO2-SiO2 composite aerogels via “thiol-ene” click reaction

Abstract We reported the preparation of a series of ZrO 2 -SiO 2 composite aerogels via the sol-gel reaction between the zirconium source (ZrOCl 2 ·8H 2 O) and the gel initiator (mercaptosuccinic acid-triethoxyvinylsilane). Such novel gel gelator was prepared by the thiol-ene click reaction using triethoxyvinylsilane (VTES) and mercaptosuccinic acid (MSA). The unique molecule structure of the gel initiator allows the in-situ modification of ZrO 2 with SiO 2 in the sol-gel reaction, which was achieved by the hydrolysis and polycondensation of siloxane with the change of the pH spontaneously. SiO 2 with the controllable content can be in-situ introduced into ZrO 2 backbone. As a result, the composite aerogel showed better thermal stability compared with pristine ZrO 2 aerogel, proved by the following facts: (i) the aerogels remained amorphous after calcination in air at 600 °C; (ii) the specific surface area maintained at 53.4 m 2 /g when the temperature rising to 1000 °C. ZrO 2 -SiO 2 composite aerogels with improved thermal stability have been prepared via the “thiol-ene” click section