摘要
以羧甲基纤维素(CMC)为配体,改变Eu^(3+)离子的浓度合成了一系列具有荧光性能的CMC/Eu(III)纳米粒子,并阐明了Eu^(3+)离子的浓度对产物结构与荧光性能的影响及淬灭机理。傅里叶变换红外光谱及扫描电镜结果表明,Eu^(3+)离子与CMC的-COO^-,-OH,以及-C-O-C相结合而形成配合物,所获得的配合物粒径在60~80 nm范围内;X射线衍射结果显示所得的产物结晶度随Eu^(3+)离子浓度增加而降低;产物的紫外吸收表明配合物的能量吸收主要来自于配体CMC。产物呈现5D0→7F1和5D0→7F2的磁偶极跃迁和电偶极跃迁的典型Eu^(3+)的特征发光,且其荧光淬灭浓度临界值为m(Eu^(3+))∶m(CMC)=0.07∶1,当m(Eu^(3+))∶m(CMC)≤0.04:1时,配合物中存在的未反应的-OH是造成荧光淬灭的主要原因,而m(Eu^(3+))∶m(CMC)大于该值时,产物中的晶胞缺陷是荧光淬灭的主要原因。
A series of CMC / Eu（ Ⅲ） nanoparticles were synthesized based on changing Eu^3＋doping concentration to carboxymethyl cellulose（ CMC）,and illuminated the effect of Eu^3＋concentration on the structure and fluorescence properties. FT-IR and SEM results indicates that the- COO-,- OH,and- C- O- C of CMC are involved in the coordination with Eu^3＋,and the particle size of nanocomplexes is in the range of 60 ~ 80 nm. The XRD results show that the crystallinity decreases with the increasing of Eu^3＋ concentration. It is found that the characteristic energy absorption of the nano-complexes is originated from CMC. The fluorescence spectrum presents typical Eu^3＋luminescence lines,namely the5D0→7F1and5D0→7F2transitions corresponding to the magnetic dipole transition and electric dipole transition. The quenching concentration of the ratio of Eu^3＋to CMC is m（ Eu^3＋） ∶ m（ CMC） = 0. 07∶ 1,when m（ Eu^3＋） ∶m（ CMC） ≤0. 04∶ 1,the unreacted- OH existing in the complexes is the main cause of fluorescence quenching; while the concentration of Eu^3＋is higher,the crystal lattice defects are mainly responsible for fluorescence quenching.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2016年第2期32-37,共6页
Polymer Materials Science & Engineering
基金
国家"973"计划项目(2010CB732201)
国家自然科学基金资助项目(31270617)
作者简介
熊犍,主要从事纤维索及其它天然高分子结构与性能研究，E-mail：lcixiong@scut．edu．cn
