ISSN:
0392-6737
Keywords:
Colloids
;
Statistical theories of liquid structure
;
Time-dependent properties
;
Conference proceedings
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Summary Charge-stabilized suspensions are characterized by the strong electrostatic interactions between the particles so that rather dilute systems may exhibit strong correlation resulting in a well-developed short-range order. This microstructure, quantitatively described by the pair distribution functiong(r), is rather different from that of (uncharged) hard spheres. It is shown how this difference affects the «hydrodynamic function»H(k), which appears in the expression for the first cumulant Γ(k)=k 2 D eff(k)=k 2 H(k)/S(k) of the dynamic autocorrelation function. Without hydrodynamic interaction,H(k)=D 0, which is the free-diffusion coefficient. Using pairwise additive hydrodynamic interaction and the lowest-order many-body theory of hydrodynamic interaction, it is found thatH(k) can deviate considerably fromD 0 even for systems of volume fractions ϕ as low as 10−3. These effects are more pronounced for collective diffusion than for self-diffusion. SinceH(k=0) is closely related to the sedimentation velocity, we have studied this quantity as a function of volume fraction. It is found that (H(0)/D 0) −1 scales asφ 1/3 at low ϕ in salt-free suspensions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02458782
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