Banjare Manoj Kumar, Behera Kamalakanta, Satnami Manmohan L, Pandey Siddharth, Ghosh Kallol K
School of Studies in Chemistry, Pt. Ravishankar Shukla University Raipur 492 010 Chhattisgarh India
Centre for Interdisciplinary Research in Basic Sciences, JMI Jamia Nagar New Delhi 110 025 India.
RSC Adv. 2018 Feb 20;8(15):7969-7979. doi: 10.1039/c7ra13557b. eCollection 2018 Feb 19.
Ionic liquids (ILs) and deep eutectic solvents (DESs) are receiving increased attention from both academic and industrial research due to their immense application potential. These designer solvents are environmentally friendly in nature with tunable physicochemical properties. In the present investigation, we have studied the aggregation behavior of a short-chain IL 1-butyl-3-methylimidazolium octylsulphate [Bmim][OS] within aqueous DESs using fluorescence, UV-vis, dynamic light scattering (DLS) and FT-IR spectroscopic techniques. We have prepared two DESs, ChCl-urea and ChCl-Gly, which are obtained by heating a mixture of an ammonium salt choline chloride with hydrogen bond donor urea or glycerol, respectively, in 1 : 2 molar ratios. The local microenvironment and size of the aggregates are obtained from steady state fluorescence (using pyrene and pyrene-1-carboxaldehyde as polarity probes) and DLS measurements, respectively. DLS results shows that IL [Bmim][OS] forms relatively larger micelles within the aqueous solution of DES ChCl-urea (avg. hydrodynamic radii = 209 nm) than compared to ChCl-Gly (avg. hydrodynamic radii = 135 nm). A significant decrease in the critical micelle concentration and increase in the aggregation number ( ) are observed within DES solutions as compared to that in water, thus indicating that the micellization process of the IL [Bmim][OS] is much favored in the DES solutions. Molecular interactions of [Bmim][OS] in DESs are revealed from FT-IR spectroscopic investigation. Furthermore, these systems were applied to study the IL-drug binding of the antidepressant drug promazine hydrochloride (PH).
离子液体（ILs）和深共熔溶剂（DESs）因其巨大的应用潜力而受到学术界和工业界研究的越来越多的关注。这些定制溶剂本质上是环境友好的，具有可调节的物理化学性质。在本研究中，我们使用荧光、紫外可见光谱、动态光散射（DLS）和傅里叶变换红外光谱技术研究了短链离子液体1-丁基-3-甲基咪唑硫酸辛酯[Bmim][OS]在水性DESs中的聚集行为。我们制备了两种DESs，氯化胆碱-尿素和氯化胆碱-甘油，它们分别是通过将氯化铵盐与氢键供体尿素或甘油按1∶2摩尔比混合加热得到的。聚集体的局部微环境和尺寸分别通过稳态荧光（使用芘和芘-1-甲醛作为极性探针）和DLS测量获得。DLS结果表明，与氯化胆碱-甘油（平均流体动力学半径=135nm）相比，离子液体[Bmim][OS]在DES氯化胆碱-尿素的水溶液中形成相对较大的胶束（平均流体动力学半径=209nm）。与在水中相比，在DES溶液中观察到临界胶束浓度显著降低和聚集数增加，这表明离子液体[Bmim][OS]的胶束化过程在DES溶液中更有利。通过傅里叶变换红外光谱研究揭示了[Bmim][OS]在DESs中的分子相互作用。此外，这些体系被用于研究抗抑郁药物盐酸丙嗪（PH）的离子液体-药物结合作用。
