the methodologies available use either speciality chemicals or corrosive treatments needing special apparatus. Is the acid functionalisation possible with simple stirring of silicon dioxide and sulphuric acid? I am not very sure of chemistry behind reaction. It Would be great if anyone could help me with this. I have silica particles with Si and oxygen content. What simple protocol can I follow?
Dear Duraisamy Tharani, you are dealing with a well known, simple and efficient and powerfull catalysts: silica sulfuric acid (SSA). Literature is really wide on its preparation and application. Prof. Zolfigol is among the most Scientists who deeply investigated this system. By the way he is on RG if you need further help. Please check the following documents. My Regards
https://doi.org/10.1002/jhet.659
https://doi.org/10.1021/acsomega.9b03262
https://doi.org/10.1016/j.catcom.2007.09.017
https://doi.org/10.1016/j.catcom.2007.08.019
https://doi.org/10.3762/bjoc.9.269
https://doi.org/10.1081/SCC-200057240
https://www.longdom.org/proceedings/sio2so3h-gel-a-convenient-and-versatile-heterogeneous-substitute-of-sulfuric-acid-for-organic-reactions-which-require-st-36058.html
https://doi.org/10.1155/2013/581465
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3941859/
https://doi.org/10.1080/07328303.2011.621042
https://doi.org/10.1039/C4RA16571C
Dear Duraisamy, in addition to the excellent and rather comprehensive answer already provided by Abdelkader BOUAZIZ I would like to add that there is a rather informative Wikipedia entry on the topic available at https://en.wikipedia.org/wiki/Silica_sulfuric_acid
Yet another useful article in which the preparation of sulfuric acid on silica-gel is described is the following:
Sulfuric acid on silica-gel: an inexpensive catalyst for aromatic nitration
Article Sulfuric Acid on Silica-gel: an Inexpensive Catalyst for Aro...
Here the catalyst was prepared by soaking 20 g of silica-gel in 25 ml of concentrated sulfuric acid. Remaining water was then removed by drying under water pump vacuum at room temperature for 5 hours followed by oven drying at ca. 130 °C over night. As a formally acidic anhydride SiO2 does not dissolve in concentrated sulfuric acid so that preparation of this catalyst become possible.
Good luck with your work!
Thank you Prof Abdelkader BOUAZIZ and Frank T. Edelmann for your time In answering a naive question. It really helps me a lot.
Dear Duraisamy,
you're very welcome. No need to call your question "naive", though. The two most noble purposes of RG are:
a) to help young researchers by answering their technical questions, and
b) to provide free access to scientific literature to every RG member.
Thus it was a pleasure for us to help you!
With best wishes, Frank Edelmann