Construction of Fluorescent Cellulose Biobased Plastics and their Potential Application in Anti-Counterfeiting Banknotes

Abstract

Development of natural polymer biobased materials that are light responsive is very useful for industrial production and our lives for a sustainable world. In this work, on the basis of the strong hydrogen bonding interaction between cellulose chains and conjugated dye molecules, fluorescent cellulose biobased plastics are fabricated successfully by hot-pressing rhodamine B-loaded and/or fluorescein-loaded cellulose hydrogels, which are prepared in an aqueous 4.6 wt% LiOH/15 wt% urea solution pre-cooled to –12 °C. The experimental results indicate that the fluorescent dye molecules are tightly fixed into the cellulose matrix through the capturing of cellulose to the hydroxyl and amino groups of rhodamine B and fluorescein. The fluorescent cellulose biobased plastics exhibit good thermal stability, excellent mechanical properties, and photoluminescence properties, with a significant fluorescent signal under UV fluorescent light. It is not hard to imagine that the RhB/cellulose biobased plastic (RhCBP) and fluorescein/cellulose biobased plastic (FCBP) thin belts or pieces could be easily embedded into paper during production because of the same cellulose component. Therefore, paper including a few of these fluorescent cellulose biobased plastics would be a good candidate for making anti-counterfeiting banknotes.