Molecular aggregation of rhodamine dyes in dispersions of layered silicates:: Influence of dye molecular structure and silicate properties
Molecular aggregation of rhodamine dyes in dispersions of layered silicates:: Influence of dye molecular structure and silicate properties
复制标题
DOI：
10.1021/jp0553378
复制
发表时间：
2006-02-09
影响因子：
3.3
通讯作者：
Iyi, N
中科院分区：
文献类型：
--
作者：
Bujdák, J;Iyi, N
用可见光谱法研究了6种罗丹明染料（罗丹明560、B、3B、19、6G、123）在层状硅酸盐（皂土和氟辉石）分散体中的分子聚集。染料分子聚集受硅酸盐和染料本身性质的影响。硅酸盐的层电荷增强了亲水阳离子染料的分子聚集。染料分子中羧酸基团的存在抑制了染料在氟hectorite（一种具有高电荷密度的硅酸盐）表面的吸附。可见光谱法可观察到低吸附或无吸附。染料与硅酸盐表面的强结合导致了染料光谱的显著变化，这主要是由于分子聚集。染料溶液与硅酸盐分散体混合后最初形成的染料组合是不稳定的。在时差光谱的基础上，研究了染料分子组合的分解、新物种的形成或分子聚集体的重排。反应途径是特定的，不仅对染料，取决于他们的分子结构和性质，而且在硅酸盐底物。
The molecular aggregation of six rhodamine dyes (rhodamine 560, B, 3B, 19, 6G, 123) in layered silicate (saponite and fluorohectorite) dispersions was investigated by using visible (vis) spectroscopy. The dye molecular aggregation was influenced by the properties of both the silicates and the dyes themselves. The layer charge of the silicates enhanced the molecular aggregation of the hydrophilic, cationic dyes. The presence of a carboxyl acid group in the dye molecules inhibited adsorption of the dyes on the surface of fluorohectorite, a silicate with a high charge density. A lower or no adsorption could be observed by vis spectroscopy. Strong association of the dyes to the silicate surface led to remarkable changes in the dye spectra, mainly due to the molecular aggregation. Dye assemblies initially formed after mixing the dye solutions with silicate dispersions were unstable. Decomposition of the dye molecular assemblies, and the formation of new species or molecular aggregate rearrangements, were studied on the bases of time-difference spectra. The reaction pathways were specific, not only for the dyes, depending upon their molecular structure and properties, but also on the silicate substrates.