Organic molecule adsorption on quartz {10.1}: An internally consistent set of adsorption energy data for 36 compounds

We have investigated the adsorption of small organic molecules on the quartz dipyramidal {10.1} surface using density functional theory (DFT). The adsorption behaviour of 36 molecules, chosen to represent a range of functional group types and molecule configurations, was examined to better understand organic compound interactions with the surface of quartz, and in extension, other silica surfaces. We analysed the contribution of various types of bonding, including hydrogen bonds, dispersion interactions and electrostatic forces, to the adsorption strengths. We found that molecules containing amine functional groups bind most strongly to quartz. Further analysis of adsorption energies from water and oil reveals that amines maintain their preferential adsorption, even in solution. Our findings advance the understanding of quartz interaction with organic molecules. The results have important implications for biomineralization processes, because organic compounds with amine groups are implicated in silica mineralization, such as for diatoms (planktonic algae). Ultimately, this work provides a computational framework for comparing adsorption properties across different Si compounds and offers insights into the molecular mechanisms influencing quartz and silicate material surface interactions in various environmental and industrial contexts.