Abstract: The generations of 0.5, 1.5, 2.5, 3.5, 4.5 of the PAMAM dendrimers and 1, 2, 3, 4 of the PAMAM dendrimers have been synthesized with an EDA core. Surface tensions of the dendrimer aqueous solution have been measured by drop-volume method. It is showed that (1) the dendrimer aqueous solutions have a surface activity and the order of the surface activity is G=4.5>G=3.5>G=2.5>G=1.5>G=0.5; (2) the plateau area of G=4.5 is more obvious than those of G=3.5 and G=2.5, the reason is not clear now; (3) as compared with G=0.5, 1.5, 2.5, 3.5, 4.5 of dendrimer, the cationic ones containing ——C₁₂H₂₅had a higher surface activity.

Key words: Dendrimer, Surface tension, Surface activity