Authors: Yan Vivian Li Lawrence M Cathles
Publish Date: 2016/03/02
Volume: 18, Issue: 3, Pages: 71-
Abstract
A new class of nearly chargeneutral carboncored nanoparticle tracers are remarkably noninteractive with solid surfaces and could provide a valuable baseline for diverse hydrological and environmental studies of subsurface flow and particle transport We investigate the causes of inertness by studying the interactions with calcite of a nanoparticle of this class synthesized from malic acid and ethanolamine Mdots dispersed in brine NaCl CaCl2 and MgCl2 solutions None of the Mdots are retained in calcite sandpacked columns when dispersed in DI water Dispersed in the NaCl and mixed brine solutions 56 of and 73 of the Mdots are initially retained but 65 and 13 of these retained particles are subsequently released when the column is flushed with DI water When dispersed in the CaCl2 and MgCl2 solutions 65 and 54 of the Mdots are initially retained and 28 and 26 subsequently released in the DI water flush The Mdots have a small negative zeta potential in all solutions but the calcite zeta potential changes from strongly negative to strongly positive across the solution series and the particle retention tracks this change Derjaguin–Landau–Verwey–Overbeek DLVO modeling of the force between a calcite probe and an Mdot coated surface shows that hydration forces repel the particles in the DI water NaCl and mixed solutions but not in the CaCl2 and MgCl2 solutions These results show that nearzero charge and strongly hydrophilic decoration are the causes of the remarkable inertness of carboncored nanoparticles and also suggest that nanoparticles could be useful in solutesurface interaction studiesThis publication is based on work supported by Award No KUSC101802 from the King Abdullah University of Science and Technology and by ARI project from Department of Energy Support was also provided by a general fund contribution to L Cathles from The International Research Institute of Stavanger
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