Two-photon induced data storage in hydrogen bonded supramolecular azopolymers

Supramolecular azopolymers were prepared through strong hydrogen bonding interaction between pyridine moiety of poly (4-vinylpyridine) (P4VP) and phenol moiety of 4-nitro- 4'-hydroxyazobenzene (AzoOH). FT-IR spectrum verifies the hydrogen bonding formed between them. High quality films of the supramolecular P4VP/(AzoOH)x (x=0.1,0.25,0.5,0.75,1.0) complexes with different azochromophore concentration were obtained by drop-coating. Erasable polarization data storage was observed in the supramolecular azopolymer films owing to two-photon-induced anisotropy of azochromophore. Moreover, with the increasing content of azochromophore, the threshold for data recording is decreased dramatically from 12 mW to 5 mW and the image recorded in supramolecular P4VP/(AzoOH)1.0 films are much more clear after storing for 3 days, respectively, which indicates that a larger proportion of AzoOH enhances both photo-orientation degree and its stability.