Subject: Re: CCL:W:Molecular dynamics of silica in H2O

From: James Kubicki <kubicki^at^geosc.psu.edu>
Date: Thu, 16 Jun 2005 09:38:08 -0400

You should look up the work of SH Garofalini.
He has done extensive SiO2-H2O simulations.
I'm not sure if this force field is suitable for your
purposes, but it is the closest thing I've seen.

At 08:04 AM 6/16/2005, you wrote:
>Hello,
>
>I want to start an MD simulation of a silica particle of size 5-10 nm in 
>aequous solution, possibly also with a few Na+ ions floating around. I 
>have a sample PDB file containing the structure of a silica nanoparticle, 
>and have tried to make a box containing the nanoparticle and some water 
>molecules using the 'genbox' utility program of GROMACS.
>
>The problem arises when defining the parameters which determine how the 
>atoms will interact. Does anyone have a good set of general parameters for 
>such a system ? I am aware of the the work of Wensink and Hoffmann 
>[Langmuir 16, 7392 (2000)], but their scheme relies on a partitioning of 
>the system into crystal, surface and water atoms and I do not know how 
>such a partitioning could be done in my case so as to best use their 
>parameterization.
>
>I'm not 100% tied to using GROMACS (any freely available and capable MD 
>code will do for some initial investigations). I would be grateful for any 
>advice on alternatives.
>
>My investigations are intended to look into the behaviour in solution of 
>silica nanoparticles formed by polymerization in solutions of sodium 
>silicates, including nucleation, growth, formation of charged 
>nanoparticles (and consequently double layers) and the effect of solution 
>pH on this process and the detailed effects on nanoparticle surface charge 
>density. The list above is long, I realize, but I would very much 
>appreciate some pointers on how to get started quickly into these 
>investigations.
>
>Many thanks in advance,
>Steve Kirk
>
>
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James Kubicki
308 Deike Bldg.
Dept. of Geosciences
The Pennsylvania State University
University Park, PA 16802
814-865-3951
814-574-7379 (Cell)
814-863-7823 (Fax)

---

From: "Patrick Senet" <psenet^at^u-bourgogne.fr>
Date: Thu, 16 Jun 2005 16:13:01 +0200

Hello,

Please forward the answers...we are interested by starting a similar problem 
(silicate planar surface in water + ions).
Many thanks,

Patrick Senet