Synthesis and Self-assembling of Wholly Aromatic Block Co-oligomers: Oligo(ether sulfone)-b-oligo(ether ketone with Sulfonic Acid Terminal Groups)

Oligo(ether sulfone)-b-oligo(ether ketone with biphenyl terminal groups) was prepared by the aromatic nucleophilic substitution and deprotection reaction cycles. The sulfonation reaction was carried out using chlorosulfuric acid. The degree of sulfonation of the resulting sulfonic acid di- and triblock co-oligomer was 51 and 57%, respectively, which estimated by 1H NMR spectrum and TGA curve. The resulting sulfonic acid diblock co-oligomer, sodium salt formed the self-assembled structure in the solid state, which is lamellar nanostructures with a periodicity of approximately 3 nm. The structures resulted from hydrophilic interactions of sodium sulfonic acid group and π-π stacking interactions.