Volume 110, Issue 24, 22 June 1999
Index of content:
Rate constants of spherical dispersions: From diffusion-limited data to nondiffusion limited results110(1999); http://dx.doi.org/10.1063/1.479050View Description Hide Description
A simple but accurate equation is derived for calculation of the overall rate constants of nondiffusion-limited incorporation of diffusing species in spherical dispersions, based on the corresponding results of the diffusion-limited cases. The proposed equation checks very well with the accurate nondiffusion limited rate constant data of three regular spherical arrays computed by Lu [J. Chem. Phys. 109, 4985 (1998)]. The relative errors are less than 5% for volume fractions as high as 0.45 for the simple cubic array and 0.6 for both the face-centered and body-centered cubic arrays. Results from the proposed equation deviate the most from the accurate data at intermediate P. Here P is a dimensionless parameter characterizing the relative rate of diffusive transport versus surface incorporation.
110(1999); http://dx.doi.org/10.1063/1.479165View Description Hide Description
The finite-size effects and packing constraints on the density profile of a hard-rod fluid in both open (grand canonical) and closed (canonical) walls have been investigated. For a finite system, the grand canonical density profile shows very different density behavior compared with the canonical density profile. At low packings, the convergence of series is shown to converge very quickly, even if only a few particles are confined in hard walls. However, the significant differences at high packings arise between the canonical and the grand canonical density profiles. The convergence is much slower in the region where the peak develops.