Microscopic Origin of the Hofmeister Effect in Gelation Kinetics of Colloidal SilicaReport as inadecuate


Microscopic Origin of the Hofmeister Effect in Gelation Kinetics of Colloidal Silica


Microscopic Origin of the Hofmeister Effect in Gelation Kinetics of Colloidal Silica - Download this document for free, or read online. Document in PDF available to download.

Publication Date: 2015-07-07

Journal Title: Journal of Physical Chemistry Letters

Publisher: American Chemical Society

Volume: 6

Issue: 15

Pages: 2881-2887

Language: English

Type: Article

Metadata: Show full item record

Citation: van der Linden, M., O. Conchúir, B., Spigone, E., Niranjan, A., Zaccone, A., & Cicuta, P. (2015). Microscopic Origin of the Hofmeister Effect in Gelation Kinetics of Colloidal Silica. Journal of Physical Chemistry Letters, 6 (15), 2881-2887.

Description: This is the accepted manuscript. The final version is available at http://pubs.acs.org/doi/abs/10.1021/acs.jpclett.5b01300.

Abstract: The gelation kinetics of silica nanoparticles is a central process in physical chemistry, yet not fully understood. Gelation times are measured to increase by over four orders of magnitude, simply changing the monovalent salt species from CsCl to LiCl. This striking effect has no microscopic explanation within current paradigms. The trend is consistent with the Hofmeister series, pointing to short-ranged solvation effects not included in the standard colloidal (DLVO) interaction potential. By implementing a simple form for short-range repulsion within a model that relates the gelation timescale to the colloidal interaction forces, we are able to explain the many orders of magnitude difference in the gelation times at fixed salt concentration. The model allows to estimate the magnitude of the non-DLVO hydration forces, which dominate the interparticle interactions at the length-scale of the hydrated ion diameter. This opens the possibility of finely tuning the gelation time-scale of nanoparticles by just adjusting the background electrolyte species.

Sponsorship: We acknowledge financial support from: Unilever Plc (E.S.); the Ernest Oppenheimer Fellowship at Cambridge (to 1st June 2014), and by the Technische Universität München Institute for Advanced Study, funded by the German Excellence Initiative and the European Union Seventh Framework Programme under grant agreement 291763 (A.Z.); the Winton Programme for the Physics of Sustainability (B.O.C.).

Identifiers:

This record's URL: http://dx.doi.org/10.1021/acs.jpclett.5b01300http://www.repository.cam.ac.uk/handle/1810/249264





Author: van der Linden, MarteO. Conchúir, BreanndánSpigone, ElisabettaNiranjan, ArunZaccone, AlessioCicuta, Pietro

Source: https://www.repository.cam.ac.uk/handle/1810/249264



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