癸基萘磺酸钠胶束中分子动态的质子核磁共振研究(英文)

DYNAMICS OF SODIUM 4-DECYL NAPHTHALENE SULFONATE MOLECULES IN MICELLES STUDIED BY ~1H NMR RELAXATION

在 2 98、3 0 3和 3 1 3K下对浓度为 0 .82和 2 .59mmol/L的癸基萘磺酸钠的重水溶液中质子的自旋 自旋弛豫 (T2 )时间进行了测量 .浓度为 0 .82mmol/L的溶液 (临界胶束浓度CMC以下 )中的所有质子的T2 值均随温度上升而增长 ,说明整个分子运动变的更自由 .然而 ,浓度在CMC以上 (2 .59mmol/L)时 ,分子中一部分参与形成栅栏层的质子的T2 值却表现出相反的效应 ,它们的运动随温度上升而变慢 ,说明在高温下为防止水分子进入疏水胶束壳内 ,这些栅栏层的质子堆积的更紧密 .同时分子中其他质子的T2 值随温度上升而增长 。

H spin spin ( T \-2) relaxation times of sodium 4 decyl naphthalene sulfonate (SDNS) protons at different concentrations of 0.82 and 2.59 mmol/L were measured at 298, 303 and 313 K. These T\-2 values give the information about the dynamic characteristic of SDNS molecules in their monomeric and micellar states. The decrease in the T\-2 values of a part of SDNS micellar protons, which participate in the formation of the palisade layer, with the increase in temperature suggests that the palisade layer becomes more tightly compact with the increase in temperature in order to prevent water penetration into the hydrophobic micellar core. While the reverse effect of the other protons in the T\-2 values with the temperature up to 313 K shows that their motion of those protons is enhanced.