Unique photoluminescence from nonconjugated alternating copolymer poly[(maleic anhydride)-alt-(vinyl acetate)]

Photoluminescence of a nonconjugated alternating copolymer poly[(maleic anhydride)-alt-(vinyl acetate)] (PMV) is studied. Through a "stabilizer-free" dispersion copolymerization, uniform PMV colloidal particles are prepared. The colloid suspension can emit blue light (λ_max 419 nm) upon UV excitation. The copolymer exhibits solvatochromism: its emission red-shifts progressively from 397 to 432 nm when the solvent is changed from acetone to dioxane to THF. The DMF, NMP and DMSO solutions of PMV show distinct magenta color, and emit blue (477 nm) and red (615 nm) lights upon photoexcitation. In contrast, no light is emitted from its water and ethanol solutions, suggesting that the anhydride groups in the polymer play a crucial role in its photoluminescence process.