Porous nanosilica is a technologically important material with potential applications in the catalysis, medicine and separations sectors. These applications demand specific porosity, surface chemistry and/or particle size. Current methods to attain these features are extremely complex and/or unsustainable, leading to significant barriers to commercialisation. Taking inspiration from biomineralisation, we have developed bioinspired synthesis. This green method (mild, one-pot and rapid synthesis in water, at room temperature and neutral pH) is sustainable when compared to traditional routes, yet offers excellent control over the properties of the materials. In this presentation, we will discuss new results relevant to bioinspired synthesis which highlight the importance of interfacial interactions for controlling the (A) synthesis, (B) purification and (C) surface modification of nanosilicas (detailed below). (A) The knowledge of the specific interactions between these additives and inorganic species has enabled green synthesis of nanosilicas of a range of properties e.g. monodisperse silica nanoparticles and mesoporous silica – this is a significant step-change compared to traditional syntheses. (B) Using recently developed molecular dynamics force-fields, we have investigated the extraction of additives from silica surfaces for the first time. This has enabled the modulation of additive-surface interaction leading to a rapid room-temperature solution method for complete extraction of organic additives. Once extracted, additives can be directly reused for further silica synthesis. Estimates of the environmental benefits of our new method compared with previous purification techniques show significant improvements in sustainability. (c) Finally, using extensive NMR analysis, we have identified the ability of the additives to catalyse condensation at silica surfaces even after the formation of silica is complete. Such surface-adsorption-then-catalysis reactivity has not been previously considered in studies of organic-inorganic surface interactions. Taken together, this presentation will show that by studying the organic-inorganic interface, we have developed a cleaner, cheaper, and readily scalable method for production of bespoke nanosilica. This is a significant technological advance which is enabling sustainable and economical scale-up of these materials for commercial applications.

Understanding interfacial interactions to unlock the potential of bioinspired nanomaterials

2019 Fall National Meeting

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