The diffusion kinetics of a molecular probe—rhodamine B—in ternary aqueous solutions containing poly(vinyl alcohol), glycerol, and surfactants was investigated using fluorescence correlation spectroscopy and dynamic light scattering. We show that the diffusion characteristics of rhodamine B in such complex systems is determined by a synergistic effect of molecular crowding and intermolecular interactions between chemical species. The presence of glycerol has no noticeable impact on rhodamine B diffusion at low concentration, but significantly slows down the diffusion of rhodamine B above 3.9% (w/v) due to a dominating steric inhibition effect. Furthermore, introducing surfactants (cationic/nonionic/anionic) to the system results in a decreased diffusion coefficient of the molecular probe. In solutions containing nonionic surfactant, this can be explained by an increased crowding effect. For ternary poly(vinyl alcohol) solutions containing cationic or anionic surfactant, surfactant—polymer and surfactant—rhodamine B interactions alongside the crowding effect of the molecules slow down the overall diffusivity of rhodamine B. The results advance our insight of molecular migration in a broad range of industrial complex formulations that incorporate multiple compounds, and highlight the importance of selecting the appropriate additives and surfactants in formulated products.

使用荧光相关光谱和动态光散射研究了分子探针罗丹明 B 在含有聚乙烯醇、甘油和表面活性剂的三元水溶液中的扩散动力学。我们表明罗丹明 B 在这种复杂系统中的扩散特性是由分子拥挤和化学物质之间的分子间相互作用的协同效应决定的。甘油的存在在低浓度下对罗丹明 B 的扩散没有明显影响，但由于占主导地位的空间抑制作用，在超过 3.9% (w/v) 时会显着减慢罗丹明 B 的扩散。此外，将表面活性剂（阳离子/非离子/阴离子）引入系统会导致分子探针的扩散系数降低。在含有非离子表面活性剂的溶液中，这可以通过增加的拥挤效应来解释。对于含有阳离子或阴离子表面活性剂的三元聚（乙烯醇）溶液，表面活性剂——聚合物和表面活性剂——罗丹明 B 相互作用以及分子的拥挤效应减慢了罗丹明 B 的整体扩散。结果提高了我们对分子迁移的广泛认识包含多种化合物的工业复杂配方的范围，并强调了在配方产品中选择合适的添加剂和表面活性剂的重要性。