| Abstract: | Poly(propyleneimine) PPI-(NH2) n ] and poly(amidoamine) PAMAM-(NH2) n ] dendrimers with n = 4, 8, 16, 32 and 64, have been functionalized with a semifluorinated carboxylic acid CF3(CF2)7CH2CH2COOH] on the surface. The thermal and liquid crystal properties of the resulting ionic dendrimers have been studied by polarized optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). All dendrimers show a smectic A (SmA) mesophase, except that derived from the fifth generation of PPI, which displays a columnar mesophase. The mesomorphic behaviour of the dendrimers is attributed to the formation of ionic bonds and to the microsegregation of the dendritic branches and the fluorinated peripheral chains. |
