[shilala]

Your question is tough to answer, so I'll go on what I think you're asking.
The size of the bead does not affect the dessicant's function of holding moisture at all, and I'm speaking in terms of the singular bead.
When different meshes are employed in different arrangements, the ability of the dessicant's function can be severely decreased, or conversely, arranged in a fashion that takes advantage of the dessicant's principles and maximize their efficacy.
For instance, and I'll only bother you with one, if a person places 4" of beads in a 12"x12" tray, he will gain almost no more reactivity or function than that of a person who places an inch of beads in the same tray. After an inch of depth, the smallest meshes are severely impaired in their ability to transfer water vapor, but it's just a simple mechanical blockage. It's no fault of the beads.
That statement has to be taken in an educated context, because if a person is using a much larger mesh, that depth of efficacy increases with the mesh size. Those are the types of things that one tests for when engineering a product so that the design of the final product takes full advantage of the dessicant's efficacy, and is not wasting a bunch of beads that aren't doing anything that's worth having them present.
It all goes to surface area, vapor pressure, airflow and lots of math.