基于有机改性硅氧烷构筑稀土掺杂氟化物纳米粒子溶胶-凝胶杂化材料及其性能研究

In recent years, sol-gel hybrid luminescent materials containing rare earth have attracted much attention. Their research work mainly focused on introducing rare-earth organic complexes into sol-gel matrix by physical mixing or chemical bonding. However, there were few studies on the introduction of rare-earth doped nanoparticles into sol-gel matrix by covalent grafting. In this project, aromatic ring and aromatic heterocyclic carboxylic acid containing auxochrome groups of mercapto, amino and hydroxyl will be used as photosensitizing ligands to synthesize aromatic carboxylic acid functionalized silica-based coupling agent by reacting with different silica-based coupling agent respectively. Then, according to the principle of rare-earth coordination chemistry, photosensitization and sol-gel reaction strategy, chemical bonding rare-earth doped fluoride nanoparticles sol-gel hybrid materials will be constructed and their properties will be studied using rare-earth doped fluoride nanoparticles as luminescent primitives and aromatic carboxylic acid functionalized silicon-based coupling agents as multifunctional (coordination, photosensitization and condensation) chemical connectors. Through this research, a simple and repeatable method for the controlled synthesis of sol-gel hybrid materials with rare-earth doped fluoride nanoparticles assembled by chemical bonds can be established and the mechanism of luminescent primitives sensitized by aromatic carboxylic acid functionalized siloxane conjugates can be clarified, which can lay a foundation for the applied research of rare-earth doped fluoride nanoparticles sol-gel hybrid materials in the fields of optoelectronic device, integrated optical communication and light-emitting sensor.

近年来，含稀土溶胶-凝胶杂化发光材料的研究备受关注，其研究主要集中于通过物理混合或化学键合的方式将稀土有机配合物引入到溶胶-凝胶基质中，而将稀土掺杂纳米粒子通过共价嫁接的方式引入到溶胶-凝胶基质中的研究却较少。本项目拟采用含有巯基、氨基、羟基助色基团的芳环、芳杂环羧酸为光敏化配体，分别与不同硅基偶联剂反应合成芳香羧酸功能化的硅基偶联剂；然后根据稀土配位化学原理、光敏化作用和溶胶-凝胶反应策略，以稀土掺杂氟化物纳米粒子为发光基元、芳香羧酸功能化硅基偶联剂为多功能（配位、光敏化和缩聚）化学连接体，构筑化学键合稀土掺杂氟化物纳米粒子溶胶-凝胶杂化材料并研究其性能。通过本项目的研究，可建立易于重复、简便易行的化学键组装的稀土掺杂氟化物纳米粒子溶胶-凝胶杂化材料的可控合成方法，阐明芳香羧酸功能化硅氧烷连接体敏化发光基元的机理，为其在光电器件、集成光通讯、发光传感等领域的应用研究奠定基础。

稀土配合物溶胶-凝胶杂化发光材料的研究已经取得了较大的突破，但是该研究依然存在需要解决的问题，如传统的合成方法反应周期过长，杂化材料的光学性能和稳定性需要进一步提高。要解决这些问题，无疑需要加速和推进新型含稀土溶胶-凝胶杂化发光材料的研究。本项目合成了三种芳香羧酸改性硅氧烷衍生物，通过1H NMR、FT-IR对所合成的芳香羧酸改性硅氧烷衍生物进行表征；采用水热法、溶剂热法、共沉淀法合成了Tb3+掺杂CaF2纳米粒子、Ce3+，Tb3+共掺杂CaF2纳米粒子，Nd3+/Er3+掺杂CaF2纳米粒子、Tb3+掺杂LaF3纳米粒子、Eu3+掺杂NaYF4/NaGdF4纳米粒子等一系列稀土掺杂氟化物纳米粒子；Cit/CaF2:Ce3+，Tb3+纳米粒子在543 nm 处的发光强度是Cit/CaF2:Tb3+纳米粒子的16倍，其水分散液的强绿色特征发射能被Cu2+离子选择性地猝灭；由于氟化的PBTA配体减小了C-H基团的高能振动对Er3+/Nd3+发光的淬灭，PBTA/CaF2:Er3+/Nd3+纳米粒子的发光强度显著强于NTA/CaF2: Er3+/Nd3+纳米粒子；芳香羧酸改性硅氧烷修饰的CaF2:Tb3+、LaF3: Tb3+纳米粒子表现出强的芳香羧酸改性硅氧烷敏化Tb3+的发光；根据稀土配位化学原理、光敏化作用和溶胶-凝胶反应策略，以CaF2: Tb3+纳米粒子、LaF3: Tb3+纳米粒子、NaYF4: Eu3+纳米粒子、NaGdF4: Eu3+纳米粒子为发光基元，芳香羧酸改性硅氧烷为化学连接体，在四乙氧基硅烷的存在下，通过水解、缩合反应合成化学键合的稀土掺杂氟化物纳米粒子溶胶-凝胶杂化材料，所合成的杂化干凝胶材料呈现均匀的单相，合成方法易于重复、简便易行，为稀土掺杂氟化物纳米粒子溶胶-凝胶杂化材料在光电器件、集成光通讯、发光传感等领域的应用研究奠定基础。