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采用巯基乙胺为配体,以硝酸铒(Er(NO3)3),硝酸镱(Yb(NO3)3),硝酸钇(Y(NO3)3)和氟化铵(NH4F)为原料,水热法制备表面含NH2基团的活性YF3:Yb3+-Er3+纳米晶;以过硫酸钾(K2S2O8)为引发剂,借助1-乙基-(3-二甲基氨基丙基)碳酰二亚胺(EDC)与N-羟基丁二酰亚胺(NHS)的偶联反应,在活性纳米晶存在下,进行N-异丙基丙烯酰胺(NIPAm),N,N’-亚甲基双丙烯酰胺(BIS)与丙烯酸的自由基共聚合,一锅法制备了YF3:Yb3+-Er3+/PNIPAm-co-PAA荧光温敏纳凝胶.对制备的纳米晶及纳凝胶的结构与荧光性能进行了表征.结果表明,纳米晶的粒径为6~10 nm,呈单分散分布;纳凝胶的粒径呈多分散分布,粒径主要分布在100~300 nm.PL光谱分析表明,活性YF3:Yb3+-Er3+纳米晶的4F7/2→4I15/2跃迁,在483和496 nm处产生明显的能级劈裂;纳凝胶中,该能级劈裂依然存在,但随温度升高发生耦合;环境温度对纳凝胶的上转换发光强度产生明显影响.
Using mercaptoethylamine as ligand, Er (NO3) 3, Yb (NO3) 3, Y (NO3) 3 and ammonium fluoride (NH4F) Method to prepare active YF3: Yb3 + -Er3 + nanocrystals containing NH2 groups on the surface; using potassium persulfate (K2S2O8) as initiator and 1-ethyl- (3- dimethylaminopropyl) carbodiimide (NIPAm), N, N’-methylenebisacrylamide (N, N’-methylenebisacrylamide) in the presence of an active nanocrystal Yb3 + -Er3 + / PNIPAm-co-PAA was prepared by free radical copolymerization of acrylic acid and BIS, and the structure and fluorescence properties of the prepared nanocrystals and nanogels were characterized The results showed that the size of nanocrystals was monodispersed with the size of 6 ~ 10 nm, the size distribution of nanocrystals was polydisperse and the particle size was mainly distributed in the range of 100 ~ 300 nm.PL spectrum analysis showed that the activity of YF3: Yb3 + -Er3 + 4F7 / 2 → 4I15 / 2 transitions of nanocrystals at 483 and 496 nm. In nanoegel, splitting of this energy level still exists, but coupling occurs with increasing temperature. The temperature has a significant effect on the upconversion luminescence intensity of nanogel.