Synthesis and gelation property of amino acids-based dendronised oligomers

The first- and second-generation dendrons constructed from alanine and aspartic acids were synthesised and further modified with a polymerisable acrylamide group at the focal point (MG1 and MG2). The corresponding dendronised oligomers were obtained by polymerisation, and then hydrolysed to afford them with multi-carboxyl groups on the periphery of branched side chains (PG1-COOH and PG2-COOH). The structures of the oligomers were characterised by ¹H NMR, Fourier transform infrared and gel permeation chromatograph, and their gelation behaviour was examined. It was found that PG1-COOH and PG2-COOH could form two-component gels, especially, PG1-COOH showed better gelation property. For example, it could gel with aliphatic primary or secondary amines in dimethylformamide and with melamine in acidic aqueous solution. Transmission electron microscopy and atomic force microscopy images showed that the gelators self-assembled into the fibrous networks.