Abstract
Wetting is essential and ubiquitous in a variety of natural and technological processes. Silicon dioxides-water systems are abundant in nature and play fundamental roles in a vast variety of novel science and engineering activities such as silicon based devices, nanoscale lab on a chip systems and DNA microarrays technologies.Although extensive experimental, theoretical and computational work has been devoted to study the nature of the interaction between silica and water, at the molecular level a complete understanding of silica-water systems has not been reached. Contact angle computations of water droplets on silica surfaces offers a useful fundamental and quantitative measurement in order to study chemical and physical properties of water-silica systems. For hydrophobic systems the static and dynamic properties of the fluid-solid interface are influenced by the presence of air. Hence, nanobubles have been observed and proposed as the origin of long range ``hydrophobic'' forces even for hydrophilic silica-water interfaces unusual phenomena related to nanobubbles have been observed. In this work we study the role of air on the wetting of amorphous silica-water systems. We conduct molecular dynamics (MD) simulations of a hydrophilic air-water-silica system using the MD package FASTTUBE. We employ quantum chemistry calculation to obtain air-silica interaction parameters for the simulations. Our simulations are based in the following force fields: i) The silica-silica interaction is based on the potential model developed by Guissani et al. ii) The water-water interaction is simulated based on the classical rigid SPC/E water model. iii) The silica-water interaction is based on the force field model developed by Hassanali et al. iv) The air-silica interaction is simulated using a Lennard-Jones (LJ) 12-6 potential, parameterised using two different approaches therefore from quantum chemistry computations, and from Lorentz-Berhelot (LB) mixing rules with values obtained from the universal force field (UFF) and from Guissani et al. v) The water-air interaction is simulated using a LJ 12-6 potential with parameters obtained using LB mixing rules and values obtained from Jiang et al.38 for nitrogen and air oxygen and from Werder et al. for water oxygen.
Original language | English |
---|---|
Title of host publication | 13th. IACIS INTERNATIONAL CONFERENCE ON SURFACE AND COLLOID SCIENCE : 83th. ACS COLLOID AND SURFACE SCIENCE SYMPOSIUM |
Number of pages | 418 |
Volume | Vol1:Theory and Computer Simulations in Interfacial and Colloidal systems |
Place of Publication | New York, NY, USA |
Publisher | ACS (American Chemical Society) and IACIS (Int. Association of Colloid and Interface Scientist) |
Publication date | 2009 |
Edition | 1. |
Publication status | Published - 2009 |
Event | International Conference on Surface and Colloid Science and 83th. ACS Colloid Surface Science Symposium : Theory and Computer Simulations in Interfacial and Colloidal systems, American Chemical Society - Columbia University, New York, NY, USA Duration: 1 Jan 2009 → … Conference number: 13 |
Conference
Conference | International Conference on Surface and Colloid Science and 83th. ACS Colloid Surface Science Symposium : Theory and Computer Simulations in Interfacial and Colloidal systems, American Chemical Society |
---|---|
Number | 13 |
City | Columbia University, New York, NY, USA |
Period | 01/01/2009 → … |
Keywords
- Silica-Water-Air interface, Silica Nanochannels, Nanofluidics, watercapillary filling in Nanochannels