Abstract: In this work, the phenomena occurring at the stage of solvent exchange treatment during the synthesis of porous silica monoliths are described using high-resolution scanning microscopy. Initially, the solution in the swollen gel network and macropores contains the tetraethoxysilane hydrolysis products, the structure-forming agent polyethylene oxide, and nitric acid. Solvent exchange treatment with a more basic solvent leads to the leaching of polyethylene oxide and promotes the polycondensation process. This results in the increase in crosslinking density, the decrease in the elasticity, and the swelling degree of the gel. The release of excess solvent in the dense gel leads to its fragmentation. The formed non-spherical fragments under basic conditions are immediately crosslinked within the skeleton of macropores. Therefore, the porous monolith macrostructure and the integrity of the block are preserved. This process is rather rapid. With further treatment, there is a slow dissolution and reprecipitation of silica from the particle surface resulting in their decrease and in an increase in the size and volume of mesopores formed between them.

Cite: Miskevich O.Y. , Serkova A.N. , Salanov A.N. , Izaak T.I.
A Detailed Study of the Mesoporous Structure Formation in the Silica Monolith with Interconnected Macropores
Journal of Sol-Gel Science and Technology. 2023. V.105. P.748–757. DOI: 10.1007/s10971-023-06051-8 WOS Scopus РИНЦ AN OpenAlex

Dates:

Submitted:	Jul 1, 2022
Accepted:	Jan 19, 2023
Published online:	Feb 3, 2023
Published print:	Mar 1, 2023

Identifiers:

Web of science:	WOS:000923661200001
Scopus:	2-s2.0-85147374370
Elibrary:	54036998
Chemical Abstracts:	2023:259978
OpenAlex:	W4319162088

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