I'm a beginner blender user, I'm trying to model this material:

which gets volume after absorbing water:

I started modeling a pile using nodes, but the resulted instances are overlapping, how to proceed to get them separated particles? (a grip/bunch of individual separated grains as in the first image)

2- I'll be glad if someone give me hint about how to model the hydrated material as in second picture (modeling and material transparent)

sorry, i can't find how to join the .blend file.

thank you All.