Long-time dynamics of charged colloidal suspensions: hydrodynamic interaction effects

Gerhard Nägele and Peter Baur

Physica A: Statistical Mechanics and its Applications, 1997, vol. 245, issue 3, 297-336

Abstract: For charge-stabilized suspensions, we study the influence of hydrodynamic interactions (HI) and electrostatic interactions on the dynamic structure factor S(q,t), and on the long-time self-diffusion coefficient DsL. Both types of interactions give rise to memory effects, which lead to a slower and non-exponential decay of S(q,t), and which cause DsL to be smaller than the short-time self-diffusion coefficient DsS. A global measure of the non-exponential decay of S(q,t) is the non-exponentiality factor Δ(q), which can be determined experimentally by dynamic light scattering. We derive microscopic expressions for the one-particle irreducible memory functions associated with Δ(q) and DsL, based on the generalized Smoluchowski equation and on a projection operator method developed recently by Kawasaki. HI are accounted for by a far-field expansion of the two-body hydrodynamic mobility tensors, by including the leading terms. We calculate Δ(q) and DsL by constructing a novel mode-coupling approximation scheme which accounts for HI, and we extend the theory to moderately polydisperse suspensions. Our results for the measurable non-exponentiality factor compare well with available experimental data. The effect of HI in charge-stabilized colloids is to reduce the non-exponentiality of S(q,t), and to cause an unexpected enhancement of DsL. Our calculations clearly demonstrate the importance of HI at volume fractions even as low as 10−3.

Keywords: Non-exponential decay; Long-time self-diffusion; Hydrodynamic interactions; Polydispersity effects; Irreducible memory functions; Mode-coupling approximation; Charge-stabilized suspensions (search for similar items in EconPapers)
Date: 1997
References: View references in EconPapers View complete reference list from CitEc
Citations:

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/S0378437197003075
Full text for ScienceDirect subscribers only. Journal offers the option of making the article available online on Science direct for a fee of $3,000

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:phsmap:v:245:y:1997:i:3:p:297-336

DOI: 10.1016/S0378-4371(97)00307-5

Access Statistics for this article

Physica A: Statistical Mechanics and its Applications is currently edited by K. A. Dawson, J. O. Indekeu, H.E. Stanley and C. Tsallis

More articles in Physica A: Statistical Mechanics and its Applications from Elsevier
Bibliographic data for series maintained by Catherine Liu ().