在NaYF_4纳米晶表面修饰不饱和基团,与甲基丙烯酸甲酯单体共聚,制备了NaYF_4-PMMA发光纳米复合聚合物。采用共价键将纳米晶镶嵌在聚合物基质中,可实现纳米粒子均匀、稳定、高浓度的掺杂。所使用的纳米发光材料为NaYF_4∶20%Yb,2%Er和NaYF_4∶20%Yb,1.5%Tm。NaYF_4∶20%Yb,2%Er纳米晶的尺寸为9~14 nm,NaYF_4∶20%Yb,1.5%Tm纳米晶的尺寸为11~15 nm。在980 nm红外光的激发下,NaYF_4∶20%Yb,2%Er-PMMA发出明亮的黄光,NaYF_4∶20%Yb,1.5%Tm-PMMA发出明亮的蓝光,分别与其对应的发光纳米晶的发射光谱完全一致。实验结果表明:NaYF_4-PMMA材料透明性良好,稳定性高,上转换发光强度大。这种上转换发光纳米复合聚合物在显示领域,特别是在真三维显示方面具有潜在的应用前景。
NaYF_4 nanoparticles coated with unsaturated functional groups were co-polymerized with methyl methacrylate( MMA) monomers through covalent bands to synthesize the NaYF_4-PMMA luminescent polymer based nanocomposites. The covalent bands between the nanoparticles and the polymer made the upconversion nanoparticles stably embedded in the polymer matrix with high doping concentrations. No obvious aggregations of nanoparticles were observed. The size of NaYF_4∶20% Yb,2% Er nanoparticls used in the experiment was 9-14 nm,and the size of NaYF_4∶ 20% Yb,1. 5% Tm nanoparticls was 11-15 nm. Under the excitation of 980 nm laser,NaYF_4∶ 20% Yb,2% Er-PMMA emitted bright yellow light and NaYF_4∶ 20% Yb,1. 5% Tm-PMMA emitted bright blue light. The emission spectra of the nanocomposites were same with the corresponding nanoparticles.The experiment results showed that these nanocomposites possessed very good transparency in visible region. This kind of upconversion luminescent polymer based nanocomposites had potential applications in the field of display, especially the true three-dimensional( 3D) volumetric display technique.