  Water is a fundamental component of life, playing a critical role in
regulating metabolic processes and facilitating the dissolution and transport
of essential molecules. However, the presence of emerging contaminants, such as
pharmaceuticals, poses significant challenges to water quality and safety.
Nanomaterials-based technologies arise as a promising tool to remove those
contaminants from water. Nevertheless, interfacial water plays a major role in
the adsorption of chemical compounds in the nanomaterials - as it plays in
biological processes such as protein folding, enzyme activity, and drug
delivery. To understand this role, in this study we employ Molecular Dynamics
(MD) simulations to explore the adsorption dynamics of potassium diclofenac
(K-DCF) on single-walled (SWCNT) and double-walled (DWCNT) carbon nanotubes,
considering both dry and wet conditions. Our findings reveal that the
structuring of water molecules around CNTs creates hydration layers that
significantly influence the accessibility of active sites and the interaction
strength between contaminants and adsorbents. Our analysis indicates higher
energy barriers for adsorption in DWCNTs compared to SWCNTs, which is
attributed to stronger water-surface interactions. This research highlights the
importance of understanding nanoscale water behavior for optimizing the design
and functionality of nanomaterials for water purification. These findings can
guide the development of more efficient and selective nanomaterials, enhancing
contaminant removal and ensuring safer water resources, while also contributing
to a deeper understanding of fundamental biological interactions.
