碳点/纤维素构建多色余辉气凝胶
Construction of Multicolor Afterglow Aerogel by Carbon Dots/CNF
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摘要: 以柠檬酸为碳源, 采用一步水热法制备了柠檬酸碳点(CDs)。将CDs掺杂到纤维素纳米纤维(CNF)中, 经过物理交联后, 制得磷光CDs@CNF气凝胶, 以CDs作为供体和罗丹明B(RhB)作为受体, 通过三重态到单重态磷光能量转移(TS-FRET)策略制备出红色余辉CDs-RhB@CNF气凝胶。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见(UV-Vis)吸收光谱、稳态/瞬态荧光光谱和国际照明委员会(CIE)色度图对气凝胶光物理性能和微观形貌表征分析, 结果显示: CDs@CNF在535 nm处的磷光寿命为144.88 ms, CDs均匀分布在CNF气凝胶中, 气凝胶呈蜂窝状多孔结构;CDs-RhB@CNF气凝胶在600 nm处的磷光寿命为102.49 ms, Förster转移效率可达65.9%;掺杂罗丹明6G(Rh6G)和罗丹明123(Rh123)的荧光染料获得了具有黄色余辉发射的CDs-Rh6G@CNF及CDs-Rh123@CNF气凝胶;进一步将负载气凝胶的磷光纸应用于美观折纸和高级防伪领域, 扩展了以天然生物质制备多色余辉材料的策略及应用领域。Abstract: Citric acid carbon dots(CDs) were prepared by a one-step hydrothermal method using citric acid as carbon source. The afterglow aerogel CDs@CNF was prepared by doping CDs into cellulose nanofibers(CNF) after physical cross-linking. The red afterglow aerogel CDs-RhB@CNF was prepared by triplet-to-singlet Förster resonance energy transfer(TS-FRET) strategy using CDs as donor and rhodamine B(RhB) as acceptor. The photophysical properties and microstructure of the aerogel were characterized by scanning electron microscopy(SEM), transmission electron microscopy(TEM), ultraviolet-visible(UV-Vis) absorption spectrum, steady-state transient fluorescence spectroscopy and International Commission on Illumination(CIE) chromatograms. The results showed that, the phosphorescence lifetime of CDs@CNF at 535 nm was 144.88 ms, the CDs were uniformly distributed in the CNF aerogel, which had a honeycomb porous structure. The phosphorescence lifetime of CDs-RhB@CNF at 600 nm was 102.49 ms, and the Förster transfer efficiency was up to 65.9%. The yellow afterglow aerogel CDs-Rh6G@CNF and CDs-Rh123@CNF were obtained by doping rhodamine 6G(Rh6G) and rhodamine 123(Rh123) with fluorescent dyes, and the aerogel-loaded phosphorescent paper was further applied in the field of aesthetic origami and advanced anti-counterfeiting, extending the strategy and application area of preparing multicolor afterglow materials from natural biomass.