File(s) under permanent embargo
Aggregation, ageing and transport properties of surface modified fumed silica dispersions
journal contribution
posted on 2010-01-01, 00:00 authored by J Nordström, A Matic, J Sun, Maria ForsythMaria Forsyth, D MacFarlaneWe have investigated the aggregation, ageing and transport properties of surface modified silica dispersions in DMSO by photon correlation spectroscopy and conductivity measurements. The surface modification introduces Li+-ions that dissociate in the dispersion creating a single Li+-ion conducting electrolyte. We show that the surface modification changes the aggregation and ageing properties of the material. There is a pronounced ageing observed for the modified silica dispersions. At high concentrations of fumed silica a gel state is found, which in the case of the surface modified silica is a very weak gel that can be rejuvenated by ultrasonic treatment. The key parameter controlling the aggregation in this system is hydrogen bonding and the surface modification results in a very low number of sites for hydrogen bonding. In addition there is a contribution from repulsive electrostatic interactions in the surface modified silica dispersions due to the highly charged surfaces of these particles. Furthermore, the Li+-ion diffusion, at low silica concentration, is three orders of magnitude faster than that of the silica particles and in the gel state the silica particles are immobile. We also find that the Li+-ion diffusion is virtually independent of the silica concentration in the dispersions.
History
Journal
Soft matterVolume
6Issue
10Pagination
2293 - 2299Publisher
Royal Society of ChemistryLocation
Cambridge, EnglandPublisher DOI
ISSN
1744-683XeISSN
1744-6848Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2010, Royal Society of ChemistryUsage metrics
Categories
No categories selectedKeywords
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC