Hydrothermal synthesis and inkjet printing of hexagonal-phase NaYF4: Ln3+ upconversion hollow microtubes for smart anti-counterfeiting encryption
Hydrothermal synthesis and inkjet printing of hexagonal-phase NaYF4: Ln3+ upconversion hollow microtubes for smart anti-counterfeiting encryption
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用于智能防伪加密的六方相NaYF4:Ln3上转换空心微管的水热合成及喷墨打印
DOI：
10.1039/c8qm00278a
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发表时间：
2018-11-01
影响因子：
7
通讯作者：
Zhang, Changfan
中科院分区：
文献类型：
--
作者：
Xie, Shaowen;Tong, Chao;Zhang, Changfan
合理设计和制造定义良好的上转换发光材料对防伪和安全应用具有重要意义。在这里，我们提出了由聚丙烯酸(PAA)功能化的六方相NaYF4：LN3+组成的新型上转换空心微管的水热合成。得到的UCHM不仅具有良好的结构和均匀的尺寸，而且在室温下还具有很强的上转换发光。通过详细的随时间变化的实验，得到了NaYF4：LiN3+晶体从立方到六方的相变和从纳米球到中空微管的形态变化之间的结构-性能关系，这有助于推导出可能的超微结构材料的生长机理。此外，通过掺杂不同的稀土离子和调整掺杂稀土离子在UCHM中的摩尔比，成功地制备了三基色(RGB)UCHM。RGB UCHM通过在乙醇、水和甘油的混合溶剂中分散制成荧光油墨。产生的RGB UCHM油墨是在普通纸张上喷墨打印的，以在环境条件下产生隐藏图像。然而，在980 nm的光激励下，隐藏的图像可以用红绿蓝三色发光读出。基于UCHMS的油墨能够以安全的方式创建光敏智能加密图案，并且这种图像加密可以空间和选择性地打印在文档上以用于防伪应用。
Rational design and fabrication of well-defined upconversion phosphors are of great significance for anti-counterfeiting and security applications. Here, we present hydrothermal synthesis of novel upconversion hollow microtubes (UCHMs) composed of poly(acrylic acid) (PAA) functionalized hexagonal-phase NaYF4: Ln3+. The resulting UCHMs possess not only well-defined structures and uniform sizes, but also strong upconversion luminescence emission at room temperature. The structure–property relationship of the NaYF4: Ln3+ crystal between the phase transition from cubic to hexagonal and morphological changes from nanospheres to hollow microtubes is obtained by detailed time-dependent experiments, which help to derive a possible growth mechanism of the UCHMs. Furthermore, by doping different lanthanide ions and tailoring the molar ratio of the doped lanthanide ions in the UCHMs, three-primary-color (RGB) UCHMs are successfully produced. The RGB UCHMs are fabricated into fluorescent inks by dispersal in a solvent mixture of ethanol, water, and glycerol. The resulting RGB UCHMs inks are inkjet printed on common paper to produce hidden images under ambient conditions. However, the hidden images can be read out with red-green-blue luminescence under 980 nm light excitation. The UCHMs-based inks enable the creation of light-responsive smart encryption patterns in a secure way, and such image encryption can be spatially and selectively printed on documents for anti-counterfeiting applications.