Morphology-controlled silicon oxide particles produced by red wiggler worms

Abstract

The preparation of silica particles by vermicomposting has gained increasing attention for use as an inventive alternative to conventional methods. The silica oxides obtained can be used in a number of technological applications. As of yet, these particles cannot be used efficiently because of the lack of research into the relationship between the bioprocess and the shape and size of the particles. The aim of this study is to synthesize silica particles by red wiggler worms using three different grasses: Equisetum hyemale, Zea mays nixtamalized, and Otatea ramirezii and to characterize the obtained particles. However, it is unclear whether the use of diverse systems causes changes in the morphology of the final product. We found that silica particles can be produced by the three studied systems. Furthermore, each system showed a different polymorphism. We demonstrated that the new materials are mesoporous with a low surface area (9–22m2g−1), but each have one specific crystal arrangement. The silicas were characterized by several techniques, namely Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, atomic-force microscopy (AFM), scanning electron microscopy (SEM), dynamic light scattering (DLS), and Brunauer–Emmett–Teller (BET) analysis.