Cellulose-based fluorescent probes: Achieving the plastic-elastomer transformation and the detection and removal of...

Cellulose is an important natural polymer and it's used as starting material in this research. We have developed cellulose-based fluorescent elastomers (CEBP) that not only undergo plastic-to-elastomer transformation, but also act as sensitive probes and adsorbents for 4-nitrophenol (4-NP) in aqueous environments. Firstly, BODIPY fluorophores with hydroxyl functional groups were prepared. And then, cellulose reacted with long-chain epoxy compounds to obtain modified cellulose. Meanwhile, polymers containing chlorine atoms at the end of the side chain was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Finally, the fluorescent polymers were covalently attached to the cellulose by a nucleophilic substitution reaction. The resulting CEBP materials display a distinct "island-sea" microstructure and is confirmed by XRD to be completely amorphous. CEBP demonstrates outstanding stretchability with a strain of up to 340%, while maintaining uniform and stable fluorescence emission even under large deformation. Rheological tests verified the formation of a stable elastic network within the material. The as-prepared CEBP exhibits high sensitivity and selectivity toward 4-NP, achieving a LOD of 85 nM and an adsorption capacity of 75.95 mg/g. In this study, a multifunctional cellulose material with adjustable mechanical, optical sensing and adsorption functions could be applied for environmental monitoring, and the plastic-elastomer transformation is achieved.