Gel swelling, kinetics

In order to investigate the direction-dependent relaxation time of isotropic as well as anisotropic gels, swelling kinetics experiments were performed. Filler-loaded spherical mPDMS samples with an initial diameter of 2 cm were used for the experiment. The gel samples were placed into cyclohexane, and the diameter of the gel was recorded by a digital Sony video camera (DCR-TRV40E). 

Geckeler, K, E, Soluble Polymer Supports for Liquid-Phase Synthesis. VoL 121, pp. 31-80. Gehrke, S, H. Synthesis, Equilibrium Swelling, Kinetics Permeability and Applications of Environmentally Responsive Gels. Vol. 110, pp. 81 -144. de GenneSy P.-G> Flexible Polymers in Nanopores. VoL 138, pp. 91-106. 

SH Gehrke. Synthesis, equilibrium swelling, kinetics, permeability and applications of environmentally responsive gels. Adv Polym Sci 110 81-144, 1993. 

J Singh, ME Weber. Kinetics of one-dimensional gel swelling and collapse for large volume change. Chem Eng Sci 51 4499-4508, 1996. 

RA Siegel. pH sensitive gels—Swelling equilibria, kinetics and applications for drug delivery. In J Kost, ed. Pulsed and Self-Regulated Drug Delivery. Boca Raton, FL CRC Press, 1990, pp 129-157. 

Gehrke, S. H. Synthesis, Equilibrium Swelling, Kinetics Permeability and Applications of Environmentally Responsive Gels. Vol. 110, pp. 81-144. 

Siegel, R. A., pH-Sensitive Gels Swelling Equilibria, Kinetics, and Applications for Drug Delivery, in Pulsed and Self-Regulated Drug Delivery (J. Kost Ed.), pp. 129-155. CRC Press, Boca Raton (1990). 

According to the swelling kinetics of a gel [2], the characteristic time of swelling (t) is proportional to the square of the characteristic length of the gel (Lj and is inversely proportional to the diffusion coefficient of the gel network in the solvent as follows ... 

In this article we review our experience with hydrophobic polyelectrolyte gel systems. In Sect. 2 we summarize the essentials of the synthesis procedure. In Sect. 3 swelling equilibrium measurements are summarized, and in Sect. 4 these measurements are used to evaluate a simple theoretical model of gel swelling. Significant quantitative discrepancies are found, the putative sources of which are discussed. Swelling and deswelling kinetics results are discussed in Sects. 5 and 6. Section 7 summarizes the article, and suggests some implications of the reported results. 

Fig. 2. Swelling kinetics curves for ( ) MMA/DMA 70/30 and (Q) EMA/DMA 70/30 gels at pH 7.0 in 0.01 M citrate. I = 0.10 set by addition of Nad. T = 25 °C. Curves drawn to guide eye. Reprinted with permission from Ref. 5. [Copyright 1988 American Chemical Society.]...

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