PRODUCTION OF HYDROPHOBIC AEROGEL

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a hydrophobic aerogel, capable of efficiently removing ammonia evolved during hydrophobic treatment without requiring the use of a large amount of a solvent. SOLUTION: A gel having a skeleton of the formula (SiO2 )m ((m) is a positive integer) and containing a silanol group is subjected to hydrophobic treatment by using a sililating agent as a hydrophobic treatment agent to produce ammonia as a by-product in the hydrophobic treatment and then dried in a supercritical state to produce a hydrophobic aerogel. In the operation, the treated solution after the hydrophobic treatment is brought into contact with carbon dioxide and ammonia in the treated solution is precipitated as ammonium carbonate and removed. Ammonia can be removed by the reaction of carbon dioxide and ammonia without using a large amount of a solvent.