SYNTHESIS AND LANGMUIR-BLODGETT MULTILAYER-FORMING PROPERTIES OF PHOTO-CROSS-LINKABLE POLYGLUTAMATE DERIVATIVES

The synthesis of polyglutamate derivatives containing methyl, octadecyl, and 11-cinnamoyl-undecyl side chains is described. The influence of the different side-chain ratios on the spreading behavior and the compressibility of the monolayers is discussed. Stable monolayers were obtained that could be transferred onto hydrophobic substrates to build up multilayers, showing an orientation of the α-helical rods parallel to the dipping direction. Multilayers were cross-linked by exposure to UV light. The cinnamoyl groups show a fast cis/trans isomerization due to the large free volume available in the layers. The change of the internal structure of the films during irradiation, annealing, and after rinsing with solvent were probed with X-ray reflectometry. It is shown that the photo-cross-linkable polyglutamates provide a negative-type photoresist without the disadvantage of swelling.