Micelle Heterogeneity from the 2D Kinetics of Solute Rotation
Micelle Heterogeneity from the 2D Kinetics of Solute Rotation
复制标题
溶质旋转二维动力学的胶束异质性
DOI：
10.1021/acs.jpclett.9b02783
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Berg, Mark A.
中科院分区：
文献类型：
--
作者：
Darvin, Jason R.;Berg, Mark A.
微结构材料的化学和物理性质随位置而变化。溶质分子的非线性物理学可以测量这些局部性质，但它们通常显示多个速率（速率色散），这使解释复杂化。在胶束的情况下，速率分散在溶质的各向异性衰减已被分配到本地各向异性或本地粘度的异质性。为了解决这一矛盾，PM597分子在SDS胶束中的旋转已被测量的极化MUPPETS（多人口周期瞬态光谱）。这种2D技术表明，非均匀性很强，局部各向异性很小。结果表明，在亚纳秒的时间尺度上，溶质只看到一个强烈的胶束结构的波动。各向异性的平均结构出现在较长的时间尺度上。
The chemical and physical properties of microstructured materials vary with position. The photophysics of solute molecules can measure these local properties, but they often show multiple rates (rate dispersion), which complicates the interpretation. In the case of micelles, rate dispersion in a solute’s anisotropy decay has been assigned to either local anisotropy or heterogeneity in the local viscosity. To resolve this conflict, the rotation of PM597 molecules in SDS micelles has been measured by polarized MUPPETS (multiple population-period transient spectroscopy). This 2D technique shows that heterogeneity is strong and that local anisotropy is minimal. The results suggest that on a subnanosecond time scale, the solute sees only one strong fluctuation of the micelle structure. The anisotropic, average structure emerges on longer time scales.