Diffusion in particles with pores of varying cross-section

✍ Scribed by Girish Ballal; Kyriacos Zygourakis

• Publisher: Elsevier Science
• Year: 1985
• Tongue: English
• Weight: 672 KB
• Volume: 40
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(85)80089-0

✦ Synopsis

Microscopic investigations of porous solids have in many cases revealed cellular pore structures with numerous large cavities interconnected through smaller neck pores. Such pore structures can be modelled by three-dimensional arrangements of elemental void spaces consisting of a single sphere that is connected to the neighboring ones by two cylindrical neck pores or constrictions. The problem of steadystate diffusion in such an elemental void space is solved analytically and the relationship between the flux across such a pore and its geometrical dimensions is established. The case of extremely small constrictions is also treated. These results are applicable to the prediction of effective diffusivities in char particles and polymer materials used for the controlled release of drugs.