Fluorescence study on the aggregation behavior of pyrene-end-capped polystyrene in solution

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 (IM)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 (IE)随加水量的增加而进一步增强 ,而IM 下降 ,直至体系产生宏观的相分离 ,此时IM 和IE 均不变 .对这一结果从分子水平上进行了讨论 ,并通过IE/IM 与I1/I3 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...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 TBF. The results may help to understand the aggregation of PS, as well as copolymers containing polystyrene block in solution containing different amount of water.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000175712200030&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701SCI(E)中文核心期刊要目总览(PKU)中国科技核心期刊(ISTIC)中国科学引文数据库(CSCD)505931-9386