Interaction Forces and Aggregation Rates of Submicron-Sized Colloidal Particles

• Research unit: COST
• Project number: C12.0034

Key words (English)

Surface forces; atomic force microscopy; colloid particle; multivalent ions

Research programs (English)

COST-Action CM1101 - Colloidal Aspects of Nanoscience for Innovative Processes and Materials

Short description (English)

Forces across aqueous solutions between individual colloidal particles in the submicron size range will be investigated and quantitatively compared with aggregation rates for the same particles. The forces will be measured with the newly developed multi-particle colloidal probe technique and the aggregation rates with time-resolved multi-angle static and dynamic light scattering. Effects of multi-valent ions on the interaction forces and aggregation rates will be addressed and discussed in terms of non-DLVO contributions, such as, ion correlation forces, hydration forces, and lateral surface hetero-geneities. This project will provide detailed insight to such non-DLVO contributions and explain why the classical DLVO theory fails to describe colloidal aggregation in the slow regime

Further information (English)

Full name of research-institution/enterprise: Université de Genève Department of Inorganic, Analytical, and Applied Chemistry Sciences II

Partners and International Organizations (English)

AT; BE; BG; HR; CZ; CY; DK; FI; FR; DE; EL;HU; IE; IL; IT; LV; LT; MT; NL; NO; PL; PT; RO; RS; SK; SI; ES; SE; CH; TR; UK

Abstract (English)

Forces across aqueous solutions between individual colloidal particles are being investigated and the effect of multivalent ions on the interaction forces and aggregation rates will be addressed. They are interpreted in terms of DLVO theory, and eventual non-DLVO contributions, such as, ion correlation forces or hydration forces. The forces are being measured with the newly developed multi-particle colloidal probe technique based on the atomic force microscope (AFM), whereby colloidal particles are attached in situ to the cantilever and the substrate in the colloidal suspension. Within the second project period we have used such direct force measurements to obtain the interaction energy profiles, which were then used to predict the colloidal stability ratio. These ratios were then compared with independently measured stability ratios by time-resolved light scattering. We have further studied force profiles in the presence of multivalent coions.

References in databases (English)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C12.0034