Bis-spironaphthooxazine based photochromic polymer materials

Abstract

The photochromism and guest binding of spiro-naphtho-oxazine dimer (SNOD) based materials were investigated. The specifically angled, conjugated dimer, SNOD, was covalently connected to α-methoxy-ω-amino-poly(ethylene glycol) (PEG) and studied under UV irradiation. Results showed the specific effects of the polymer chain on their photochromic properties and relaxation kinetics. These new materials exhibited repeatable photo-switchability and little kinetics dependency on solvent polarity. The nanoscale micelles were prepared by self-assembly of amphiphilic SNOD–PEG conjugates in aqueous medium. A palladium catalyst as a guest agent was encapsulated in the micelle core, which reduced the thermal closing rate of the merocyanine isomer of the spirooxazine dimer. SNOD was also conjugated onto solid polymer beads and investigated for the binding affinity with dyes and catalysts. The stable binding affinity towards the palladium catalyst indicated potential applications for selective recognition, extraction, and controlled release.