Abstract
| - Four new hybrid (bolaphile/amphiphile) ion-pairs were synthesized. Electron microscopy indicatedthat each of these forms bilayer membranes upon dispersion in aqueous media. Membraneproperties have also been examined by differential scanning calorimetry, microcalorimetry,temperature-dependent fluorescence anisotropy measurements, and UV−vis spectroscopy. The Tmvalues for the vesicular 1, 2, 3, 4, and 5 were 38, 12, 85, 31.3, and 41.6 °C, respectively. Interestinglythe Tm values for 1 and 3 were found to depend on their concentration. The entrapment of smallsolute and the release capability have also been examined to demonstrate that these bilayers formenclosed vesicles. X-ray diffraction of the cast films has been performed to understand the natureand the thickness of these membrane organizations. The membrane widths ranged from 33 to 47Å. Finally, the above observations have been analyzed in light of the results obtained from molecularmodeling studies. Thus we have demonstrated that membrane properties can be modulated bysimple structural changes at the amphiphile level. It was shown that by judicious incorporationof central, isomeric, disubstituted aromatic units as structural anchors into different bolaphiles,one can modulate the properties of the resulting vesicles.
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