On the hydration of subnanometric antifouling organosilane adlayers: A molecular dynamics simulation

• Published in: Journal of colloid and interface science Vol. 437; pp. 197 - 204
• Main Authors: Sheikh, Sonia, Blaszykowski, Christophe, Nolan, Robert, Thompson, Damien, Thompson, Michael
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.2015
• Subjects: Antifouling; Computer simulation; Exchange; Flexibility; Gain; Hydration; Joints; Molecular dynamics; Molecular Dynamics Simulation; Nanoparticles; Organosilane adlayer; Organosilicon Compounds - chemistry; Silanes - chemistry; Surface hydration; Water; Water; Surface hydration; Organosilane adlayer; Molecular dynamics simulation; Antifouling
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2014.09.025

[Display omitted] •Computational probing of the nanoscale hydration of ultrathin antifouling adlayers.•Connection between surface hydration and antifouling supported by MD simulations.•Surface antifouling discussed in terms of a set of basic requirements.•These are hydrophilicity and kosmotropicity, hydration strength, and water dynamicity.•Conclusions are in line with those previously drawn in the literature. 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.