On the other hand, dendrimers, being highly branched The interactions between poly(amidoamine) dendrimers with surpolymers, have become the subject of extensive studies beface carboxylic groups for generations G(0.5-5.5) and positively cause their functional groups and specific shape have unique charged alumina particles were investigated at pH 5 by measuring properties compared with those of conventional polymers the adsorbed amount of dendrimers, the z potential, and the disper- . For example, polyamidoamine dendrimers with surface sion stability of alumina suspensions. The amount of dendrimers carboxylic groups in the earlier generations interact weakly adsorbed increased with increasing concentration of dendrimers and with cationic surfactant, but the later generations of the denthen attained a saturation, where the saturated amount in weight drimers can induce cooperative interactions among bound of dendrimers adsorbed became larger from G(0.5) to G(5.5). In surfactant molecules (8). Further, dendrimers have abilities addition, alumina particles were flocculated over a wide concentration region of the earlier generations G(0.5-1.5), but they showed to form organized superstructures at the interfaces (9-12); a dispersion-flocculation-redispersion sequence with dendrimer thus, it is very important to characterize adsorption behaviors concentration for the later generations G(2.5-5.5). The z potentials at various interfaces.
of alumina particles decreased with increasing concentration of den-
In this study, the interactions of poly(amidoamine) dendrimers as well as increasing generations of dendrimers. These redrimers with alumina particles were investigated by measursults indicate that the earlier denderimers operate as electrolytes ing dendrimer adsorption, z potential, and dispersion stabiland that the later dendrimers behave like an anionic surfactant or ity of alumina suspensions.
polyelectrolyte for alumina dispersion.