Colloids and Surfaces A: Physicochemical and Engineering Aspects, Volume 440, 5 January 2014, Pages 131-135.
Hiroshi Maeda, Ken-ichi Nakamura, Hisayuki Yamane, Shigeo Sasaki, Rie Kakehashi.
Department of Chemistry, Faculty of Science, Kyushu University, 812-8581 Fukuoka, Japan and
Osaka Municipal Technical Research Institute, Morinomiya Joto-ku, 536-8553 Osaka, Japan
Abstract
A rapid transport of polyacrylates through aqueous dextran solutions was reported. The transported amountQ linearly increased with time t instead of t1/2. The rapid transport is associated with the formation of finger-like flows, a kind of dissipative structure. The transport rate V increased with the linear charge density of polyacrylic acid but became constant independent of the charge density if the latter exceeds a critical value. The counterion condensation was strongly suggested from this peculiar dependence on the charge density. The transport rate decreased with increasing NaCl concentration. At 0.5 M NaCl, the transport was no longer rapid but took place as a diffusion process. As another matrix–gradient system, transport of polyvinylpyrrolidone (PVP) through aqueous sodium polyacrylate solutions was also examined and rapid transport of PVP was found.