化学学报 ›› 2002, Vol. 60 ›› Issue (5): 931-938. 上一篇    下一篇

研究论文

用荧光方法研究端基为芘的聚苯乙烯在溶液中的聚集行为

唐廷基;叶宇;李子臣;杜福胜;张昕;李福绵   

  1. 北京大学化学学院高分子科学与工程系.北京(100871)
  • 发布日期:2002-05-15

Fluorescence Study on the Aggregation Behavior of Pyrene-end-capped Polystyrene in Solution

Tang Tingji;Ye Yu;Li Zichen;Du Fusheng;Zhang Xin;Li Fumian   

  1. Department of Polymer Science & Engineering, College of Chemistry, Peking University.Beijing(100871)
  • Published:2002-05-15

利用原子转移自由基聚合(ATRP) 方法合成了窄分布的端基含有芘或萘的聚 苯乙烯(Py-PS和Na-PS)。研究了Py-PS在四氢呋喃(THF)溶液中的荧光发射光谱 随加水量的变化。结果表明,加水初期随着加水量的增加,对应于芘的单体荧光发 射峰强度(I_M)增加,当水加到一定量时,观察到由芘形成的激基缔合物( excimer)的荧光光谱峰,其强度(I_E)随加水量的增加而进一步增强,而I_M下 降,直至体系产生宏观的相分离,此时I_M和I_E均不变。对这一结果从分子水平上 进行了讨论,并通过I_E/I_M与I_1/I_3随加水量的变化得到了不同浓度下Py-PS在 THF中聚集的临界加水量。另外,我们也用非辐射能量转移(NRET)的方法研究了 Py-PS混合溶液的聚集。这些结果对于进一步研究含聚苯乙烯链段的嵌段共聚物在 溶液中的聚集有重要意义。

关键词: 聚苯乙烯, 聚集体, 芘, 萘, 荧光

Low polydispersive polystyrenes, tethered with pyrene (Py-PS) or naphthalene (Na-PS) at one end of the chain, were synthesized by atom transform radical polymerization (ATRP). The fluorescence emission spectra of Py-PS in THF were measured with different amount of water added. The results indicate that the "monomer" fluorescence intensity (I_M) of pyrene increased progressively with the increase of water content; and as the water content reached a certain amount, the emission of pyrene excimer was observed, whose intensity (I_E) increased when water was further added, until a macroscopical phase separation appeared. The critical added water contents for Py-PS at three concentrations were obtained from the changes of I_E/I_M and I_1/I_3 with the addition of water. Nonradiative energy transfer (NRET) was also exploited for a mixture of Py-PS and Na-PS in THF. The results may help to understand the aggregation of PS, as well as copolymers containing polystyrene block in solution containing different amount of water.

Key words: POLYSTYRENE, AGGREGALES, PYRENE, NAPHTHALENE, FLUORESCENCE

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