物理化学学报 >> 2001, Vol. 17 >> Issue (09): 776-780.doi: 10.3866/PKU.WHXB20010903

研究论文 上一篇    下一篇

N-乙烯基咔唑标记甲基丙烯酸-苊烯共聚物的荧光特性

尹艺青;房喻;胡道道;高改玲   

  1. 陕西师范大学化学系,西安 710062
  • 收稿日期:2001-02-06 修回日期:2001-03-14 发布日期:2001-09-15
  • 通讯作者: 房喻 E-mail:yfang@snnu.edu.cn

Fluorescence Properties of N-vinylcarbazole Labeled Methacrylic Acid-Acenaphthylene Copolymers

Yin Yi-Qing;Fang Yu;Hu Dao-Dao;Gao Gai-Ling   

  1. Department of Chemistry,Shaanxi Normal University,Xi′an 710062
  • Received:2001-02-06 Revised:2001-03-14 Published:2001-09-15
  • Contact: Fang Yu E-mail:yfang@snnu.edu.cn

摘要: 合成了苊烯(ACE)含量依次为4.3、7.5、15.1及20.8 mol%的N乙烯基咔唑(NVCz)标记甲基丙烯酸(MAA)苊烯共聚物(PMAAACE/NVCz)和ACE含量仅为0.5 mol%的ACEMAA共聚物(PMAAACE),研究了各共聚物在稀水溶液中的荧光行为和pH、表面活性剂等对共聚物荧光特性的影响.实验发现:在酸性介质中共聚物的压缩线团构象使激发态缔合物荧光相对增强,ACE到NVCz能量转移效率增加;碱性介质中共聚物构象相对松散,ACE到NVCz能量转移效率降低,因此荧光光谱中NVCz特征几乎消失.阴离子表面活性剂十二烷基磺酸钠(SDS),阳离子表面活性剂十六烷基三甲基溴化铵(AHTB)以及中性表面活性剂吐温80的引入使共聚物在酸性介质中的单体荧光特征增强,ACE到NVCz的能量转移效率下降;在碱性介质中引入AHTB部分中和了共聚物链上的负电荷,使共聚物构象重新卷曲,ACE到NVCz的能量转移效率提高,荧光光谱中NVCz特征重新出现,ACE单体荧光特征相应减少;在碱性介质中引入SDS以及吐温80对共聚物荧光光谱影响不大.

关键词: 甲基丙烯酸, 苊烯, N-乙烯基咔唑, 共聚物, 荧光

Abstract: A series of Nvinylcarbazole(NVCz) labeled methacrylic acid(MAA)acenaphthylene(ACE) copo-lymers(PMAAACE/NVCz),with ACE content of 4.3,7.5,15.1 and 20.8 mol%,respectively,and a ACEMAA copolymer(PMAAACE) with ACE content of 0.5 mol% have been synthesized. The fluorescence properties of the dilute aqueous solutions of the copolymers and the effect of pH,surfactants upon the properties have been studied in some detail. It was demonstrated that the hypercoiled conformation of the copolymers at low pH made their fluorescence emission to be dominated by ACE excimer and/or NVCz emission. At higher pH,however,the copolymers adopted an extended coil conformation that decreases significantly the efficiency of nonradiative energy transfer from ACE to NVCz. And therefore,the fluorescence emission of the copolymers at higher pH lacked the characteristics of NVCz. Introduction of surfactants had a significant effect upon the fluorescence properties of the copolymers. At low pH,adding any of sodium dodecyl sulfate(SDS),ammonium hexadecyl trimethyl bromide(AHTB) and Tween 80 decreased the efficiency of nonradiative energy transfer from ACE to NVCz due to partially extension of the copolymer coil,and thereby reduced NVCz characteristics in the fluorescence spectra of the copolymers. At higher pH,AHTB,a cationic surfactant,increased the efficiency of nonradiative energy transfer from ACE to NVCz due to partial neutralization of the negative charges along the copolymer chains,and thereby NVCz emission appeared in the fluorescence spectrum of the copolymer. The introduction of SDS or Tween 80 had little effect upon the fluorescence emission of the copolymers at higher pH.

Key words: Methacrylic acid, Acenaphthylene, N-vinylcarbazole, Copolymers,  Fluorescence