Gel fraction measurements (Fig. 7) also indicate that the latex particle size influences the rate of increase of the gel content. The gel fraction of latex comprising 80 nm particles reaches a plateau value after around 15 min. However, the rate of gelation becomes slower with increasing latex particle size (150 and 300 nm). In order to achieve the maximum gel fraction, the ADH must diffuse a distance on the order of the particle radius. The dependence of gelation rate on the particle size indicates that the reaction is limited by the diffusion of ADH into the latex particles. Our