Compression-Permeability Properties of Compressed Bed of Superabsorbent Hydrogel Particles

Abstract

The average pore size of the gel network of a superabsorbent hydrogel particle was evaluated based on the data of the permeation rate of water through the compressed bed of gels obtained with the use of a compression-permeability cell (C-P cell). The pore size evaluated based on the Happel's cell model using the C-P cell data was compared with that obtained from the Kozeny-Carman equation in which the Kozeny constant k was assumed to be 5.0. It was clarified that the use of k = 5.0 in Kozeny-Carman equation underestimated the pore size compared to the calculations using the Happel's cell model. Moreover, the effect of bound water in the gel was clarified.

Keywords:

• Compression-permeability cell
• Kozeny constant
• Pore size
• Specific flow resistance
• Superabsorbent hydrogel

ACKNOWLEDGEMENT

This work has been supported in part by a Grant-in-Aid for Scientific Research from Ministry of Education, Japan. The authors wish to acknowledge with sincere gratitude the financial support leading to the publication of this article. The authors also acknowledge the valuable assistance rendered by H.Y. Lee.