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

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.