title: Size-tunable micron-bubbles based on fluorous-fluorous interactions of perfluorinated dendritic polyglycerols.
abstract: This paper describes the behavior of various generations of polyglycerol dendrimers that contain a perfluorinated shell. The aggregation in organic solvents is based on supramolecular fluorous-fluorous interactions, which can be described by means of (19)F NMR spectroscopy. In order to study the interaction and aggregation phenomena of dendrimers with perfluorinated shell and perfluoro-tagged guest molecules we investigated [G3.5]-dendrimer with a perfluorinated shell in the presence of perfluoro-tagged disperse red. Noteworthy, the interaction intensities varied in an unexpected manner depending on the equivalents of perfluoro-tagged guest molecules added to the dendrimers in solution which then formed supramolecular complexes based on fluorous-fluorous interactions. We found that these complexes aggregated around residual air in the solvent to form stable micron-sized bubbles. Their sizes correlated with the interaction intensities measured for certain dendrimer-guest molecule ratios. Degassing of the solutions led to a quasi phase separation between organic and fluorous phase, whereby the dendrimers formed the fluorous phases. Regassing the sample with air afforded bubbles of the initial size again.
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Zieringer
authors.forename: Abel
authors.initials: A
authors.lastname: Garcia-Bernabé
authors.forename: Burkhard
authors.initials: B
authors.lastname: Costisella
authors.forename: Heiko
authors.initials: H
authors.lastname: Glatz
authors.forename: Willi
authors.initials: W
authors.lastname: Bannwarth
authors.forename: Rainer
authors.initials: R
authors.lastname: Haag