中文摘要：

使用可生物降解的羧甲基纤维素（CMC）和Eu^3＋络合反应，在不同的pH值下制备了CMC／Eu纳米络合粒子．FT-IR结果证实CMC链上的羧基、未被取代的羟基中的氧原子及醚键的氧原子均参与了与Eu^3＋的反应；SEM及TFM结果表明，所合成的CMC／Eu络舍物是纳米级的，并呈现较弱的多晶型结构；固态紫外吸收光谱表明，CMC是一个良好的能量供体和荧光敏化剂．产物的粒径及其分布与粒子荧光性质间具有依赖关系．pH=7时，所制备的产物的粒径最小（150～200nm）、分布最均匀，其荧光强度最强，荧光单色性也高；随着pH值的增大，粒子团聚加剧，产物的粒径增大，其荧光强度相应减弱，这一结果体现了量子尺寸效应．

英文摘要：

In this paper, CMC/Eu complex nanoparticles were synthesized at different pH values by the reaction of Eu^3＋ and biodegradable carboxymethyl cellulose （CMC）. FT-IR results confirm that the carboxyl groups on CMC chains, the oxygen atoms of unsubstituted hydroxyl groups and the oxygen atoms of ether bonds all involve in the reaction with Eu^3＋ SEM and TEM results show that the synthesized CMC/Eu particles are in a nanoseale and present weak polycrystalline structure. Solid UV-Vis absorption spectra show that CMC is a good energy donor and fluorescent sensitizer. Moreover, it is found that there is a strong dependence of particle size and distribution on the fluorescence properties of CMC/Eu nanoparticles, and that pH value greatly affects the particle size, the particle size distribution and the fluorescence properties ; for instance, the sample synthesized at pH 7 is of the smallest particle size （150 ~200nm）, the most uniform size distribution, the strongest fluorescence intensity and high fluores- cence monochromatieity, and, with the increase of pH value, the nanoparticles aggregate more seriously, the particle size increases, and the fluorescence intensity accordingly reduces. All these findings reflect the quantum size effect.