Relationship between Rate-Limiting Process and Scaling Law in Gel Growth Induced by Liquid-Liquid Contact

Gelation through the liquid-liquid contact between a polymer solution and a gelator solution has been attempted with various combinations of gelator and polymer solutions. In many combinations, the gel growth dynamics is expressed as [Formula: see text] , where [Formula: see text] is the gel thickness and [Formula: see text] is the elapsed time, and the scaling law holds for the relationship between [Formula: see text] and [Formula: see text]. In the blood plasma gelation, however, the crossover of the growth behavior from [Formula: see text] in the early stage to [Formula: see text] in the late stage was observed. It was found that the crossover behavior is caused by a change in the rate-limiting process of growth from the free-energy-limited process to the diffusion-limited process. How, then, would the crossover phenomenon be described in terms of the scaling law? We found that the scaling law does not hold in the early stage owing to the characteristic length attributable to the free energy difference between the sol-gel phases, but it does in the late stage. We also discussed the analysis method for the crossover in terms of the scaling law.