Abstract
We modified a method of methanol supercritical drying by adding water, nitric acid and ammonia when preparing silica aerogels from tetramethoxysilane. We found that gel-component extraction during supercritical drying and the microstructure of prepared aerogels were affected by these additives. We compared the effects of the additives to the effects created during the normal supercritical drying process. Ethanol, 1-propanol, and carbon dioxide supercritical drying were the methods studied for comparison. We found that gel-component extraction decreased in the modified-method cases. We also found that adding water was the most effective modification to decrease gel-component extraction. The constituting particle and pore sizes were increased when water or base was added. The specific surface area was increased when acid was added. These results are discussed in this paper in terms of the sol–gel reaction during supercritical drying.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
