title: First-principles molecular dynamics simulations of NH4(+) and CH3COO(-) adsorption at the aqueous quartz interface.
abstract: The ability to exert molecular-level control at the aqueous interface between biomolecules and inorganic substrates is pivotal to advancing applications ranging from sustainable manufacturing to targeted therapeutics. Progress is hindered by a lack of structural information of these interfaces with atomic resolution. Molecular simulation is one approach to obtain such data, but can be limited by the reliability of the force-field used. First-principles simulations, in principle, can provide insights into such aqueous interfaces, but are resource-intensive, limiting previous first-principles studies to approximate the environment of liquid water. Here, we use Car-Parrinello simulations to investigate adsorption of two charged adsorbates that are functional groups common to all amino-acids--ethanoate and ammonium--at the interface between hydroxylated quartz and liquid water, directly incorporating full solvation effects at the interface. Our findings reveal the stable character of carboxylate-quartz binding, as well as the surprisingly indifferent nature of ammonium-quartz interactions, in liquid water.
authors.affiliation: Department of Chemistry and Centre for Scientific Computing, University of Warwick, Coventry CV4 7AL, United Kingdom.
authors.forename: Louise B
authors.initials: LB
authors.lastname: Wright
authors.forename: Tiffany R
authors.initials: TR
authors.lastname: Walsh
mesh_terms: D000085:Acetates / Q000737:chemistry*; D000327:Adsorption; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D011791:Quartz / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000085:Acetates; D000644:Quaternary Ammonium Compounds; D014867:Water; D011791:Quartz