@article{a48d513898064dc3b63b57b22932259c,
title = "Curvature-induced hydrophobicity at imogolite-water interfaces",
abstract = "Imogolite, a nanotubular aluminosilicate mineral, is commonly found in volcanic soils, where it exerts a control on carbon dynamics. Synthetic imogolites are used for the removal of contaminants from industrial effluents and are considered for a range of other applications including gas adsorption and functionalised heterogeneous catalysts. In spite of their environmental and industrial relevance, the properties of imogolite-water interfaces remain poorly understood. Here, an experimental and computational study is presented in which the structure and energetics of water are characterized on the curved external surface of imogolite and the hydrophilicity of this surface is contrasted with that of gibbsite, its planar counterpart. Atomic force spectroscopy experiments show that in spite of their identical surface structure, imogolite has a lower hygroscopicity than gibbsite. Molecular dynamics simulations provide an explanation for this observation: the curvature of imogolite prevents the formation of in-plane H-bonds along the directions of the nanotube circumference, lowering the enthalpy of adsorption of water molecules. The different arrangement of surface H-bonds and the resulting differences in hydration properties also affects the acidity constants of surface hydroxyl groups. This {\textquoteleft}nanotube effect{\textquoteright} may be relevant to other nanotubular systems with high curvatures, potentially impacting their wetting properties, their colloidal stability and their affinity towards hydrophobic organic moieties.",
author = "Alejandro Fernandez-Martinez and Jinhui Tao and Wallace, {Adam F.} and Bourg, {Ian C.} and Johnson, {Mark R.} and {De Yoreo}, {James J.} and Garrison Sposito and Cuello, {Gabriel J.} and Laurent Charlet",
note = "Funding Information: Barry Bickmore and Kideok K. Kwon are gratefully acknowledged for enriching discussions. Diana Alvarez Fernandez (Alcoa Corp.) is thanked for providing the gibbsite sample. Lo{\"i}c Vidal (Inst. Sciences des Mat{\'e}riaux de Mulhouse, France) is thanked for TEM analyses. A. F.-M. acknowledges the R{\'e}gion Rh{\^o}ne-Alpes for the financial support received through an Explora'DOC fellowship for a 6 months stay at the University of California, Berkeley. 2PT analysis was performed by A. F. W. with support of the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Chemical Sciences, Geosciences, & Biosciences (CSGB) Division, under Award Number DE-SC0018439. I. C. B. was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Program under Award DESC0018419. Molecular dynamics simulations were performed using resources of the National Energy Research Scientific Computing Center (NERSC), which is supported by the U.S. Department of Energy, Office of Science, under Award DE-AC02-05CH11231. Funding Information: Barry Bickmore and Kideok K. Kwon are gratefully acknowledged for enriching discussions. Diana Alvarez Fernandez (Alcoa Corp.) is thanked for providing the gibbsite sample. Lo{\"i}c Vidal (Inst. Sciences des Mat{\'e}riaux de Mulhouse, France) is thanked for TEM analyses. A. F.-M. acknowledges the R{\'e}gion Rh{\^o}ne-Alpes for the financial support received through an Explora'DOC fellowship for a 6 months stay at the University of California, Berkeley. 2PT analysis was performed by A. F. W. with support of the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences (BES), Chemical Sciences, Geosciences, & Biosciences (CSGB) Division, under Award Number DE-SC0018439. I. C. B. was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Geosciences Program under Award DE-SC0018419. Molecular dynamics simulations were performed using resources of the National Energy Research Scientific Computing Center (NERSC), which is supported by the U.S. Department of Energy, Office of Science, under Award DE-AC02-05CH11231. Publisher Copyright: {\textcopyright} The Royal Society of Chemistry 2020.",
year = "2020",
month = sep,
doi = "10.1039/d0en00304b",
language = "English (US)",
volume = "7",
pages = "2759--2772",
journal = "Environmental Science: Nano",
issn = "2051-8153",
publisher = "Royal Society of Chemistry",
number = "9",
}