Organic Ultralong Room Temperature Phosphorescence Materials with Tunable Responsiveness from Cellulose

The construction of organic room temperature phosphorescence (RTP) materials has attracted wide attention. Herein, two kinds of intrinsic organic RTP materials with multiple responsiveness were obtained by anionic and zwitterionic modifications of cellulose. Anionic cellulose RTP materials have obvious excitation-wavelength dependence, pH responsiveness, humidity responsiveness, and temperature responsiveness. Their phosphorescence performance can be regulated by controlling the degree of substitution of the anionic groups and the chemical structure of the aryl groups. The phosphorescence afterglow of cellulose propyl sulfonate-phenylboronic acid pinacol ester (C-SO3-PhB(OMe2)2) is 15 s, and the phosphorescence lifetime is 1237 ms. The phosphorescence performance of the zwitterionic cellulose RTP materials depends on the zwitterionic group. Both anionic and zwitterionic cellulose RTP materials have organic solvent resistance. After being soaked in common organic solvents for 7 days, they can still maintain RTP performance, such as methanol, ethanol, acetone, etc. In addition, they have water solubility and processability. Through the environmentally friendly aqueous solution processing methods, phosphorescent patterns with different responsive behaviors are obtained, indicating a huge potential in anticounterfeiting, information encryption, and so on.