title: On the hydration of subnanometric antifouling organosilane adlayers: a molecular dynamics simulation.
abstract: The connection between antifouling and surface hydration is a fascinating but daunting question to answer. Herein, we use molecular dynamics (MD) computer simulations to gain further insight into the role of surface functionalities in the molecular-level structuration of water (surface kosmotropicity)--within and atop subnanometric organosilane adlayers that were shown in previous experimental work to display varied antifouling behavior. Our simulations support the hypothesized intimate link between surface hydration and antifouling, in particular the importance of both internal and interfacial hydrophilicity and kosmotropicity. The antifouling mechanism is also discussed in terms of surface dehydration energy and water dynamicity (lability and mobility), notably the crucial requirement for clustered water molecules to remain tightly bound for extensive periods of time--i.e. exhibit slow exchange dynamics. A substrate effect on surface hydration, which would also participate in endowing antifouling adlayers with hydrogel-like characteristics, is also proposed. In contrast, the role of adlayer flexibility, if any, is assigned a secondary role in these ultrathin structures made of short building blocks. The conclusions from this work are well in line with those previously drawn in the literature.
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Sonia
authors.initials: S
authors.lastname: Sheikh
authors.affiliation: Econous Systems Inc., 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
authors.forename: Christophe
authors.initials: C
authors.lastname: Blaszykowski
authors.affiliation: Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland.
authors.forename: Robert
authors.initials: R
authors.lastname: Nolan
authors.affiliation: Tyndall National Institute, University College Cork, Lee Maltings, Dyke Parade, Cork, Ireland; Department of Physics and Energy, University of Limerick, Limerick, Ireland; Materials and Surface Science Institute, University of Limerick, Limerick, Ireland. Electronic address: damien.thompson@ul.ie.
authors.forename: Damien
authors.initials: D
authors.lastname: Thompson
authors.affiliation: Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada; Econous Systems Inc., 80 St. George Street, Toronto, Ontario M5S 3H6, Canada. Electronic address: mikethom@chem.utoronto.ca.
authors.forename: Michael
authors.initials: M
authors.lastname: Thompson
mesh_terms: D056004:Molecular Dynamics Simulation; D053758:Nanoparticles; D017646:Organosilicon Compounds / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*
chemical_list: D017646:Organosilicon Compounds; D012821:Silanes
keywords: Antifouling; Molecular dynamics simulation; Organosilane adlayer; Surface hydration; Water