Work

Unveiling the Early Species of Silica-Based Materials: Raman Characterization of Silica Oligomers

Year: 2026

Type: article

Abstract: Silica oligomers formed in solutions are difficult to characterize due to their size and chemical dynamics. Raman spectroscopy is well suited to track such structures, provided that a clear and unambiguous identification of the compounds is established. We report a comprehensive theoretical and experimental study of the spectra of key polysilicic acids species. We compute ab initio spectra at both the harmonic static and molecular dynamics levels that we compare with experimental Raman spectra. Silica-containing solutions with different polymerization ratios were obtained by tuning the pH in an aqueous media. Finally, we unambiguously assign vibrational modes to linear, cyclic, and cage-like silica oligomers. Our findings reveal trends in the ν sym (Si-O-Si) band that correlate with the backbone structure supporting its use for the unique determination of these oligomers enabling reliable, quick and easy in situ identification of silicic acid oligomers in soluble silica mixtures.

Source: Nano Letters

DOI: 10.1021/acs.nanolett.6c01212

Authors: Fileto Rodríguez, Ionut Tranca, Pablo Beato, Mónica Calatayud, Frederik Tielens

Institutions: Vrije Universiteit Brussel, Haldor Topsoe (Denmark), Centre National de la Recherche Scientifique, Sorbonne Université, Molécule aux Nanos-objets : Réactivité, Interactions et Spectroscopies

Language: English

Topic: Silicone and Siloxane Chemistry

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: Vrije Universiteit Brussel, H2020 LEIT Advanced Manufacturing and Processing

Award: Characterization and HARmonization for Industrial Standardisation of advanced MAterials