Self-organization of poly(allylamine)s having hydrophobic groups and its effect on the interaction with small molecules. 2. Fluorescence lifetime and ESR techniques
Self-organization of poly(allylamine)s having hydrophobic groups and its effect on the interaction with small molecules. 2. Fluorescence lifetime and ESR techniques
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DOI：
10.1021/ma00017a011
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发表时间：
1991-08
期刊：
影响因子：
5.5
通讯作者：
T. Seo;Seiji Take;T. Akimoto;K. Hamada;T. Iijima
中科院分区：
文献类型：
--
作者：
T. Seo;Seiji Take;T. Akimoto;K. Hamada;T. Iijima
采用纳秒荧光寿命和ESR技术研究了含长烷基或长苄基的聚烯丙胺（PAA）与荧光探针在水溶液中的相互作用。将荧光衰减曲线解卷积为两部分：探针在两亲性多阳离子的疏水球和在大量水中的寿命分别为14-22 ns和r2=3-5 ns。自旋探针的旋转相关时间（tr）也分别大于10 ns和约0.1 ns。紧凑的聚合物畴在低浓度范围内形成（约10“4 M），并在较高的浓度范围内保持其结构。随着链长和取代基含量的增加，其值也随之增加。结果表明，畴的极性越低，位于畴内的探针受到的限制越大。十二烷基化的PAA结构域内部有一个硬核，随着ph的降低而松动。另一方面，苯基化的PAA结构域结构对探针分子具有更好的空间适应性。据估计，在这种聚合物中，探针的迁移率比在由小表面活性剂形成的胶束中要低。
Nanosecond fluorescence lifetime and ESR techniques were used to investigate the interaction of poly (allylamine) s (PAA) containing long alkyl or benzyl groups with fluorescent probes in an aqueous solution. The fluorescence decay curve was deconvoluted into twocomponents: lifetimes= 14-22 ns and r2=3-5 ns are assigned to the probes in the hydrophobic sphere of the amphiphilic polycation and in bulk water, respectively. The rotational correlation times (tr) for thespin probe were also obtained as greater than 10 ns and approximately 0.1 ns, respectively. The compact polymer domain is formed in a low concentration range (approximately 10" 4 M) and keeps its structure up to the higher concentration range. The values of increase with an increase in the chain length and the content of substituent groups. This result suggests that the lower the polarity of the domain, the greater the restriction of the probe located in the domain. The dodecylated PAA has a hard core in the interior of the domain, which loosens with a decrease in pH. On the other hand, the domain structure of the benzylated PAA has better sterical adaptability for probe molecules. The mobility of the probe was estimated to be lower in such a polymer assembly than in micelles formed from small surfactants.