Formation of organized adsorption layers by amphiphilic dendrimers

The formation of organized adsorption films by amphiphilic AB-type surface- block dendrimers (generation G = 3,4) with hydroxyl group/n-hexyl group ter minals on solid substrates has been investigated by atomic force microscopy , contact angle, and surface plasmon resonance. Then the surface characteri stics have been compared with those of symmetric poly(amido amine) dendrime r (PAMAM). While the adsorption film of PAMAM is rather flat, surface-block dendrimers form bilayers and their accumulation because of their amphiphil ic character. Dendrimers in bilayer, which is formed by pairing between hyd rophobic blocks, take 'pancake' structure. Adsorption film surface has hydr ophilic character, suggesting the hydrophilic OH terminal block faced to th e solution. The amount of adsorption is more for the third-generation dendr imer than for the fourth-generation dendrimer, and the adsorption proceeds more for surface-block dendrimers than for PAMAM in relation to the hydroph obicity of dendrimers. (C) 2000 Elsevier Science B.V. All rights reserved.