掺核壳纳米粒子的全息光致聚合物光化动力学的原位拉曼光谱研究

Photopolymer materials have many outstanding advantages in holographic storage, such as ultra-high storage density and storage capacity, ultra-fast access speed, high diffraction efficiency and sensitivity. Research shows that the shrinkage of the materials can be solved when some proper nanoparticles are doped into them. However, owing to lack of the effective in-situ test methods, the research about the photochemical dynamic mechanism of the photopolymers doped nanoparticles have not been thorough and systematic. Correspondingly, both the optimization of their performance and their applications for holographic storage have been hindered. Hence, in this project, acrylamide / polyvinyl alcohol holographic photopolymer doped proper noble metal core-shell nanoparticles (APHPNPs) will be designed and prepared. Using its in-situ Raman spectra, the photochemical dynamic mechanism of the holographic storage material will be researched. The researches are as follows: The test system about both holographic recording and the in-situ Raman detection will be built. In the test process, the interrelation between the physical/chemical changes of some components and their in-situ Raman spectra will be researched. Some internal standard molecules will be set between the shell and the core of the nanoparticles to act as the Raman detection standard. Finally, the photochemical dynamic mechanism can be researched more thoroughly, and the holographic storage performance can be improved.

在全息存储方面，光致聚合物材料具有超高存储密度与存储容量、超快存取速率、高的衍射效率与感光灵敏度等众多突出的优点。研究表明，在光致聚合物中掺入适当的纳米粒子可解决材料的缩皱问题。然而，因缺乏有效的原位检测方法，人们对掺纳米粒子光致聚合物的光化动力学研究不够系统深入，从而影响其性能的优化和在全息存储领域的应用。鉴于此，本项目拟制备以贵金属核壳纳米粒子为掺杂剂的丙烯酰胺/聚乙烯醇类全息光致聚合物（APHPNPs）材料，利用原位拉曼光谱研究该全息存储材料的光化动力学问题。项目中拟构建全息记录与拉曼检测联用装置，研究APHPNPs材料在存储过程中各组分发生的物理化学变化与其原位拉曼光谱之间的关系。其中，纳米粒子的核壳之间吸附有内标分子，作为材料拉曼检测的对照标准。最终实现探究APHPNPs材料的光化动力学机制，提高光致聚合物材料的全息存储性能的目的。

光致聚合物材料在全息数据存储、全息传感器、太阳能聚集器、折射或衍射等光学元件、3D显示器、生物医学等领域有着极大的应用潜力。然而，因缺乏有效的原位检测方法，人们对光致聚合物的光化动力学研究不够系统深入，从而影响其性能的优化和在各个领域的应用。鉴于此，项目组制备了以Au纳米球或者纳米星为核的多种核壳纳米粒子来原位拉曼检测光致聚合物的光化动力学过程。如制备了Au@SiO2、Au@Ag、Au@CdS或者Au@ZIF-8等核壳纳米粒子，分别掺入不同光敏剂、不同组分配比的丙烯酰胺（AA）/聚乙烯醇（PVA）类光致聚合物中，制备出APHPNPs材料。此外，在制备核壳纳米粒子时，也可在核、壳界面之间吸附拉曼探针分子用于研究材料中纳米粒子的运动等性质。这些核壳纳米粒子作为APHPNPs材料的掺杂剂不仅能调制材料的折射率并减少样品缩皱，同时也能利用其等离子激元效应显著增强材料某些组分或探针分子的拉曼信号。项目组还搭建了模拟光致聚合物全息记录与拉曼检测联用装置，原位拉曼检测APHPNPs体系中多种成分的拉曼光谱变化，用于研究该材料在曝光过程中各组分发生的物理和化学变化与其原位拉曼光谱之间的关系。该方法也可为其他光致聚合物材料在不同领域的研究提供参考。