RETRACTED ARTICLE: Atomic insight into hydration shells around facetted nanoparticles

Abstract

Nanoparticles in solution interact with their surroundings via hydration shells. Although the structure of these shells is used to explain nanoscopic properties, experimental structural insight is still missing. Here we show how to access the hydration shell structures around colloidal nanoparticles in scattering experiments. For this, we synthesize variably functionalized magnetic iron oxide nanoparticle dispersions. Irrespective of the capping agent, we identify three distinct interatomic distances within 2.5 Å from the particle surface which belong to dissociatively and molecularly adsorbed water molecules, based on theoretical predictions. A weaker restructured hydration shell extends up to 15 Å. Our results show that the crystal structure dictates the hydration shell structure. Surprisingly, facets of 7 and 15 nm particles behave like planar surfaces. These findings bridge the large gap between spectroscopic studies on hydrogen bond networks and theoretical advances in solvation science.

Synthesis and Characterization of Amorphous Iron Oxide Nanoparticles by the Sonochemical Method and Their Application for the Remediation of Heavy Metals from Wastewater

“…TEM analysis requires the sample in the dry state whereas DLS allows the sample in the solvated state where solvent molecules associated with the nanoparticle surface (forms hydration layer) while estimating particle size by TEM, this hydration layer is not present hence lower particle size values was observed [ 59 , 60 ]. The average particle size of the synthesized IONPs is 550 nm and the PDI value is 0.015 which is in good agreement with the size of the IONPs.…”

“…The size of particle reported in DLS having higher values as compared to the TEM, due to the fact that in DLS, hydrodynamic sphere formed around the nanoparticles due to the difference is particle charge and dispersion medium under the influence of Brownian motion, the hydrodynamic diameter includes the core and any molecule adsorbed over the surface of the nanoparticle, which is why the particle size value seems to be higher. TEM analysis requires the sample in the dry state whereas DLS allows the sample in the solvated state where solvent molecules associated with the nanoparticle surface (forms hydration layer) while TEM analysis requires the sample in the dry state whereas DLS allows the sample in the solvated state where solvent molecules associated with the nanoparticle surface (forms hydration layer) while estimating particle size by TEM, this hydration layer is not present hence lower particle size values was observed [59,60]. The average particle size of the synthesized IONPs is 550 nm and the PDI value is 0.015 which is in good agreement with the size of the IONPs.…”

Polymeric Solvation Shells around Nanotubes: Mesoscopic Simulation of Interfaces in Nanochannels

“…74 Such a layering of liquids has also been observed around colloidal nanoparticles in bulk. 22,23 Furthermore, similar layering patterns are shown to be predominant in polymers as soon as they come in contact with a solid surface. 57,58,75 Considering the close correlation between solvation forces and density oscillations, it is reasonable to take a similar function to model the density oscillations of short polymer chains in the vicinity of the NT.…”

Ultrasmall Manganese Ferrites as Multimodal Bioimaging Agents and Fenton/Haber-Weiss Catalysts

“…The effect of the ionic strength in the saline solution (0.9 % NaCl) can be understood considering that the hydration forces are responsible for the colloidal stability. [10][11] In the dry state, the UMFNPs are in direct contact and then in the van der Waals regime of attractive forces between NPs. During rehydration, water molecules must compete with these forces to re-form a hydration shell.…”