MICROGELS AND FRACTAL STRUCTURES AT INTERFACES AND SURFACES

The behavior of microgels near surfaces and their adsorption is studie d by simple scaling theory. Two different types of microgels can be st udied, i.e., fractal type microgels and randomly crosslinked polymer c hains. In the first case the gel can be described mainly by introducin g a spectral dimension. The second type requires more attention and us es the number of crosslinks as parameter. The main result is that soft gels with weakly coupled crosslinks and a low number of crosslinks ad sorb much better than hard gels, with many crosslinks. Similar results for fractal gels and branched polymer are presented. Fractal gels wit h low connectivity adsorb easier than gels with a large connectivity d imension. We discuss also consequences on surface protection by microg els.