基于稀土掺杂上转换/功能聚合物杂化微球构建光子晶体膜及协同发光机制研究

Fluorescent anti-counterfeiting is an important branch of material chemical anti-counterfeiting technology. However, the current fluorescent anti-counterfeiting technologies are mainly limited by the single color and poor of concealment and stability. This project is focused on the preparation of rare earth doped NaYF4 up-conversion nanoparticles (UCNPs)/functional polymer composite photonic crystal film and the revelation of the synergistic luminescence mechanism of UCNPs and polymer colloid photonic crystal film. The composite photonic crystal film combines the luminescence concealment of UCNPs and the multi color property of polymer colloid photonic crystal film, which will endow the photonic crystal film multiple security property. . To accomplish our goal, UCNPs are firstly synthesized by using multi ligand polymer with trithiocarbonate end group as ligand and stabilizer. Subsequently, core-shell structure polymer coated UCNPs hybrid colloids are synthesized by using UCNPs as seed through seed emulsion RAFT polymerization. The advantages of seed emulsion RAFT polymerization provide the easy control of the colloid size, core shell ratio and chemical component of the prepared polymer coated UCNPs hybrid colloids. By choosing special monomer such as N-isopropyl acrylamide and N-(4-vinylbenzyl)-N,N-dibutylamine as polymerization monomer, polymer coated UCNPs hybrid colloids with stimuli-responsive polymer shell can be easily prepared. Followed, the composite photonic crystal film is constructed by the self-assemble of the as-synthesized polymer coated UCNPs hybrid colloids. The effects of colloid size, core shell ratio and external environmental stimuli on the spectral property composite photonic crystal film will be systematic studied and the synergistic luminescence mechanism of UCNPs and polymer colloid photonic crystal film will be resultantly revealed. This project is anticipated to develop a new strategy for the controlled synthesis of polymer coated UCNPs hybrid colloids. Besides, the regulations of colloid size, core shell ratio and external environmental stimuli influence on the spectral property composite photonic crystal film and the synergistic luminescence mechanism of UCNPs and polymer colloid photonic crystal film will be revealed. . The accomplishment of this project will offer a potential theoretical guidance for the application of rare earth doped NaYF4 UCNPs/functional polymer composite photonic crystal film in fluorescent anti-counterfeiting area.

针对目前荧光防伪技术存在色彩单一、隐蔽性和稳定性不佳等问题，本项目提出结合稀土掺杂NaYF4上转换纳米颗粒（UCNPs）发光隐蔽性和光子晶体膜多色彩的特点，制备UCNPs/功能聚合物光子晶体膜，并研究其协同发光机制，以期获得多重防伪功能荧光薄膜。为此，拟通过多配体聚合物调控下的水热法合成表面含有活性基团的UCNPs；以UCNPs为种子，通过种子乳液活性自由基聚合，可控制备具有核壳结构响应性聚合物包覆UCNPs纳米杂化胶体；利用纳米杂化胶体的自组装构建UCNPs/功能聚合物光子晶体膜。重点研究纳米杂化胶体尺寸、核壳比以及外界环境刺激对UCNPs/功能聚合物光子晶体膜光谱性能的影响。本项目实施有望开发一条可控制备功能聚合物包覆UCNPs纳米杂化胶体的可行性路线，揭示UCNPs与聚合物光子晶体膜协同发光机制，为稀土掺杂NaYF4上转换/功能聚合物光子晶体膜在荧光防伪中的应用提供理论依据。

本项目针对目前荧光防伪技术存在色彩单一、隐蔽性和稳定性不佳等问题，结合稀土掺杂NaYF4上转换纳米颗粒发光隐蔽性和光子晶体膜多色彩的特点，制备响应性聚合物包覆上转换纳米晶核壳杂化胶体，并利用响应性聚合物包覆上转换纳米晶核壳杂化胶体在一定条件下的有序组装，构建稀土上转换/功能聚合物光子晶体薄膜。项目组围绕性能优异、荧光可调上转换稀土掺杂NaYF4纳米晶体的合成，取得了一系列原创性研究成果，先后开发出荧光增强型NaYF4:Ln3+@NaYF4:Yb3+Ln3+核壳纳米球，哑铃型上/下转换荧光NaYF4:Ln3+@NaGdF4:Ln3+核壳纳米颗粒，SiO2包覆碳量子点/稀土掺杂NaYF4核壳纳米颗粒，NaYF4:Ln3+@可逆光致变色聚合物核壳纳米颗粒，套管结构NaYF4:Yb3+,Tm3+@NaGdF4:Ce3+,Eu3+晶体等，并探讨了它们在荧光防伪中的应用。致力于聚合物包覆稀土掺杂NaYF4纳米胶体自组装构建光子晶体薄膜，开发出了聚苯乙烯包覆NaYF4:Ln3+@NaYF4:Yb3+Ln3+核壳纳米微球，并利用其自组装构建出荧光光子晶体薄膜，总结纳米杂化胶体尺寸、核壳比以及外界环境刺激对光子晶体膜禁带效应的影响，揭示了光子晶体膜禁带效应对稀土上转换发光性能的影响规律；开发了具有高强韧自修复可调上转换荧光的agar/pHEAA双网络水凝胶；开发了稀土掺杂NaYF4空心管/PLGA-PEG-PLGA复合水凝胶用于骨修复的无创监测治疗。此外，在项目资助下开展了可穿戴柔性凝胶传感器的研究，利用天然高分子产物（多糖、蛋白质）可逆的溶胶-凝胶性质、良好的生物相容性和粘附性，通过在凝胶网络结构中引入不同价态的金属离子（Li+、K+、Fe3+等），利用天然高分子与聚合物网络之间的多重作用相互协同，研制出一系列高强韧、自粘附的天然高分子基导电双网络水凝胶，并探讨了它们在柔性传感器、摩擦纳米发电机的构建及应用。经过项目组成员的四年的努力，基本达到了预期研究目标。共发表SCI论文19篇，其中ESI热点论文1篇，中科院1区论文8篇，中科院2区论文8篇。获得湖南省自然科学三等奖1项，中国包装联合会科技进步二等奖1项，获得授权国家发明专利5项，联合培养毕业博士研究生3名，毕业硕士研究生6名。