Studies of a novel polymerizable amphiphilic dendrimer

In the present study, we have synthesized a polymerizable amphiphilic dendr imer by attaching 10,12-pentacosadiynoic acid (PDA) to a third generation p oly(amidoamine) (PAMAM) dendrimer core (PDA-PAMAM). This dendrimer was char acterized by H-1 NMR and MALDI-TOF mass spectroscopy. The amphiphilic prope rty of this dendrimer has been studied. Surface pressure and surface dipole moment-area isotherm measurements have shown that PDA-PAMAM forms a stable monolayer at the air-water interface with a limiting molecular area of 460 Angstrom(2) per molecule. The compressed monolayer can be readily polymeri zed upon UV irradiation, as like other PDA derivatives. The topography of t he monolayer was observed by Brewster angle microscopy (BAM) as well as by the environmental scanning electron microscopy (ESEM). We found a good corr elation between the size and shape of monolayer domains observed with the B AM and ESEM techniques. To our knowledge, this is the first time wet mode E SEM has been used to characterize L-B film. The wet mode ensures that L-B f ilms remain intact without being damaged by the high vacuum system of tradi tional SEM. As a preliminary study, we have found that this new dendrimer f orms colloidal particles in chloroform solution and can be readily polymeri zed by UV irradiation. (C) 2000 Elsevier Science B.V. All rights reserved.