Formation of ionic liquid submicron particles. 1H and 19F nuclear magnetic resonance spectroscopic studies
Formation of ionic liquid submicron particles. 1H and 19F nuclear magnetic resonance spectroscopic studies
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DOI：
10.1080/01932691.2017.1381617
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发表时间：
2018-07
影响因子：
2.2
通讯作者：
S. Takegami;Kitaro Watanabe;Atsuko Konishi;T. Kitade
中科院分区：
文献类型：
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作者：
S. Takegami;Kitaro Watanabe;Atsuko Konishi;T. Kitade
摘要将离子液体N-（2-甲氧基乙基）-N-甲基吡咯烷双（三氟甲磺酰基）酰亚胺（Pyr 12 O 1 TFSI）与非离子表面活性剂Tween 20和Span 80乳化，制备了新型离子液体亚微米粒子（ILSPs）。ILSP的平均粒径和zeta电位分别约为580 nm和−30 mV。使用1H和19 F核磁共振（NMR）光谱方法表征ILSPs。ILSP悬浮液的1H和19 F NMR光谱中Pyr 12 O 1+阳离子和TFSI−阴离子的化学位移与纯Pyr 12 O 1 TFSI的化学位移一致。这表明在ILSP悬浮液中大部分Pyr 12 O 1 TFSI仍处于IL状态。此外，1H-1H核Overhauser效应相关的光谱测量表明，ILSP液滴包含Pyr 12 O 1 TFSI在净IL立体状态，即使在ILSP悬浮液中，和Pyr 12 O 1 TFSI物种定位在液滴表面与表面活性剂的疏水酰基侧链相互作用。这些NMR光谱的结果表明，ILSPs形成的IL-在水微乳液中，其中液滴的净Pyr 12 O 1 TFSI被包围的两个表面活性剂，即，吐温20和司盘80。图形摘要
ABSTRACT We prepared novel ionic liquid submicron particles (ILSPs) in water by emulsifying the ionic liquid (IL) N-(2-methoxyethyl)-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr12O1TFSI), which is immiscible with water, with the nonionic surfactants Tween 20 and Span 80. The mean particle size and zeta potential of the ILSPs were about 580 nm and −30 mV, respectively. The ILSPs were characterized using 1H and 19F nuclear magnetic resonance (NMR) spectroscopic methods. The chemical shifts of the Pyr12O1+ cation and TFSI− anion in the 1H and 19F NMR spectra of the ILSP suspension were consistent with those corresponding to pure Pyr12O1TFSI. This indicated that most of the Pyr12O1TFSI was still in the IL state in the ILSP suspension. In addition, 1H–1H nuclear Overhauser effect correlated spectroscopic measurements showed that the ILSP droplets contained Pyr12O1TFSI in the neat IL steric state even in the ILSP suspension, and Pyr12O1TFSI species localized in the droplet surfaces interacted with the hydrophobic acyl side chains of the surfactants. These NMR spectroscopic results show that the ILSPs formed an IL-in-water microemulsion in which droplets of neat Pyr12O1TFSI were surrounded by the two surfactants, that is, Tween 20 and Span 80. GRAPHICAL ABSTRACT