Amphiphilic diblock dendrimers: Synthesis and incorporation in Langmuir and Langmuir-Blodgett films

A new dendron with peripheral long alkyl chains and containing five C-60 un its in the branching shell has been prepared and attached to a Frechet-type dendron functionalized with ethylene glycol chains. The peripheral substit ution of the resulting globular dendrimer with hydrophobic chains on one he misphere and hydrophilic groups on the other provides the perfect hydrophob ic/hydrophilic balance allowing the formation of stable Langmuir films. Fur thermore, a perfect reversibility has been observed in successive compressi on/decompression cycles. The diblock structure of the dendrimer has been al so crucial for the efficient transfer of the Langmuir films in order to obt ain well-ordered multilayered Langmuir-Blodgett films. This approach appear s particularly interesting since functional groups not well adapted for the preparation of Langmuir and Langmuir-Blodgett films such as fullerenes can be attached into the branching shell of the dendritic structure and, thus, efficiently incorporated in thin ordered films.