@article{ca7f860f17a943af8f9111650218cfbf,
title = "Atomic Origins of the Self-Healing Function in Cement-Polymer Composites",
abstract = "Motivated by recent advances in self-healing cement and epoxy polymer composites, we present a combined ab initio molecular dynamics and sum frequency generation (SFG) vibrational spectroscopy study of a calcium-silicate-hydrate/polymer interface. On stable, low-defect surfaces, the polymer only weakly adheres through coordination and hydrogen bonding interactions and can be easily mobilized toward defected surfaces. Conversely, on fractured surfaces, the polymer strongly anchors through ionic Ca-O bonds resulting from the deprotonation of polymer hydroxyl groups. In addition, polymer S-S groups are turned away from the cement-polymer interface, allowing for the self-healing function within the polymer. The overall elasticity and healing properties of these composites stem from a flexible hydrogen bonding network that can readily adapt to surface morphology. The theoretical vibrational signals associated with the proposed cement-polymer interfacial chemistry were confirmed experimentally by SFG vibrational spectroscopy.",
keywords = "C-S-H model, SFG, ab initio molecular simulations, geothermal, self-healing cement, well-bore cement",
author = "Nguyen, {Manh Thuong} and Zheming Wang and Rod, {Kenton A.} and Childers, {M. Ian} and Carlos Fernandez and Koech, {Phillip K.} and Bennett, {Wendy D.} and Roger Rousseau and Glezakou, {Vassiliki Alexandra}",
note = "Funding Information: This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract no. DE-AC02-05CH11231. The SFG measurements were performed at the William R. Wiley Environmental Molecular Science Laboratory (EMSL), a national scientific user facility sponsored by the U.S. Department of Energy{\textquoteright}s Office of Biological and Environmental Research. The authors thank Anthony Guzman (EED) for assistance with sample preparation. Funding Information: M.-T.N., R.R., and V.-A.G. designed, executed, and analyzed the simulations and wrote the manuscript. Z.W. performed the SFG-VS studies. C.F. proposed the SFG-VS experiments and with P.K.K. co-designed the approach for the SFG sample preparation. K.A.R., M.I.C., and W.D.B. prepared the polymer− cement samples. Funding Funding for this research was provided by the Department of Energy{\textquoteright}s Geothermal Technology Office. Pacific Northwest National Laboratory is operated by Battelle for the U.S. DOE under contract DE-AC06-76RLO 1830. Notes The authors declare no competing financial interest.",
year = "2018",
month = jan,
day = "24",
doi = "10.1021/acsami.7b13309",
language = "English",
volume = "10",
pages = "3011--3019",
journal = "ACS applied materials & interfaces",
issn = "1944-8244",
publisher = "American Chemical Society",
number = "3",
}