一种聚苯乙烯荧光微球的制备及发光机理研究  

Preparation of Polystyrene-based Fluorescent Microspheres and Their Luminescence Mechanism

作　　者：徐玉良[1] 曲剑波[1] 王晓娟[1] 刘俊毅[1] 李士海[1] 刘建国[1] 

机构地区：[1]中国石油大学(华东)生物工程与技术中心,青岛266580

出　　处：《高分子学报》2016年第10期1368-1373,共6页Acta Polymerica Sinica

摘　　要：以聚苯乙烯（PS）微球为基质,与乙酰氯通过Friedel-Crafts反应得到具有荧光性质的乙酰化聚苯乙烯微球（PS-AC）.红外光谱（FTIR）分析表明苯环上已成功偶联了乙酰基.我们推测PS-AC微球的荧光现象是由聚苯乙烯分子链中的苯环与羰基双键通过π-π共轭形成的刚性平面结构引起的.为了验证该发光机理,以乙基苯和乙酰氯为原料通过Friedel-Crafts酰基化反应合成了一种与荧光微球发光基团具有相似结构的小分子化学物-对乙基苯乙酮.荧光发射光谱分析表明,对乙基苯乙酮与荧光微球在350-400 nm范围内激发光源的激发作用下都能在400-600 nm范围内产生稳定的荧光发射峰.而紫外-可见吸收光谱表明,与PS微球、乙基苯和乙酰氯相比,PS-AC微球与对乙基苯乙酮在300-400 nm范围内出现了新的吸收带,属于新形成的共轭体系的吸收.这种新的共轭体系可以将微球吸收的紫外光或紫光转变成可见的荧光.以上实验结果表明,本研究制备的荧光微球的发光现象是由苯环π键与羰基双键的共轭作用产生的.Polystyrene-based （PS-AC） fluorescent microspheres were prepared by reaction of polystyrene （PS） microspheres with acetyl chloride through Friedel-Crafls acylation. FTIR analysis showed that acetyl group was successfully coupled onto PS microspheres surface through covalent bond. The fluorescent phenomenon of these microspheres was induced by the new conjugate system between benzene ring and substituent group. To confirm the emission mechanism, p-ethylacetophenone was synthesized by reaction of ethyl benzene with acetyl chloride. Fluorescence emission spectra revealed that a strong broad emission was observed between 400 nm to 600 nm upon excitation from 350 nm to 400 nm in both spectra of p- ethylacetophenone and the fluorescent microspheres. Compared with PS microspheres,ethylbenzene and acetyl chloride,both PS-AC and p-ethylacetophenone exhibited a new broad absorption peak ranging from 300 nm to 400 nm in ultraviolet spectrum. These changes confirmed that new conjugated structure, generated through Friedel-Crafts acylation,can convert ultraviolet absorbed by novel conjugated system into visible fluorescence. These results indicated that fluorescence phenomenon of modified PS microspheres was induced by the conjugative effect between benzene ring and carbonyl group.

关 键 词：聚苯乙烯荧光微球 FRIEDEL-CRAFTS反应 荧光机理 π-π共轭 

分 类 号：O632.12[理学—高分子化学]