Molecular Design for Micrometer-Scale Self-Assembly of Amphiphilic dendrimer

点击翻译按钮获取中文摘要

Dipeptide-core poly (benzyl ether) dendrimers, tert-Boc-Tyr(Ln)-Ala (Ln = n-layered dendritic wedge) (n = 3, 4), formed a physical gel in several organic solvents. The gel displayed strong CD bands at the absorption bands of the dendritic wedge, in addition to an enhanced CD band due to the dipeptide core. Infrared spectroscopy and DSC analysis indicated that the gelation occurs via hydrogen-bonding interactions of the dipeptide core, which are possibly stabilized by van der Waals forces among the dendritic wedges. SEM analysis showed that the dried gel contains micrometer-scale fibers, which are bundles of numerous elementary fibrils with a diameter of approximately 20 nm. In relation to this achievement, we also found that an amphiphilic poly (benzyl ether) dendrimer with an exterior carboxylic acid surface forms a uniform micelle with a diameter of 250nm in phosphate buffer solution at pH 6.3. These two findings provide a new strategy for the design of micrometer-scale superstructured dendritic materials with nanometric precision.