Rheological and Ionic Transport Properties of Nanocomposite Electrolytes Based on Protic Ionic Liquids and Silica Nanoparticles
Rheological and Ionic Transport Properties of Nanocomposite Electrolytes Based on Protic Ionic Liquids and Silica Nanoparticles
复制标题
基于质子离子液体和二氧化硅纳米粒子的纳米复合电解质的流变学和离子传输特性
DOI：
10.1021/acs.langmuir.9b02848
复制
发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Watanabe Masayoshi
中科院分区：
文献类型：
--
作者：
Marium Mayeesha;Hoque Mahfuzul;Miran Muhammed Shah;Thomas Morgan L.;Kawamura Izuru;Ueno Kazuhide;Dokko Kaoru;Watanabe Masayoshi
研究了亲水性纳米二氧化硅（AEROSIL 200）对质子化1，8-二氮杂双环[5.4.0]十一碳-7-烯阳离子（DBU）组成的质子离子液体（PIL）的流变学和输运性质的影响。SiO2纳米粒子表面的硅烷醇基团与PIL离子之间的相互作用影响了粒子的聚集性质和氢键环境，反映在其胶体悬浮液的非线性流变行为和输运性质上。与由二氧化硅纳米粒子在[DBU][TFSA]（[TFSA] = [N（SO2 CF 3）2]）、[DBU][TfO]（[TfO] = [CF 3SO 3]）和[DBU][TFA]（[TFA] = [CF 3CO 2]）中的胶体悬浮液形成的剪切稀化凝胶相反，在[DBU][MSA]（[MSA] = [CH 3SO 3]）体系中形成剪切增稠稳定悬浮液。硅烷醇基团和[DBU][MSA]离子之间的相对较强的相互作用以及该PIL通过氢键形成较厚溶剂化层的能力被认为是这种独特行为的原因。此外，[DBU][MSA]-二氧化硅体系在一定的二氧化硅浓度下表现出电导率的大幅增强。这种增强没有观察到在其他PIL-二氧化硅复合材料，表现出剪切稀化行为。即使离子的扩散被发现是限制在二氧化硅的存在下，[MSA]阴离子和二氧化硅表面之间的优先更强的相互作用导致的电荷载流子的数量增加。
In this study, the effect of hydrophilic silica nanoparticle (AEROSIL 200) addition on the rheological and transport properties of several protic ionic liquids (PILs) consisting of protonated 1,8-diazabicyclo[5.4.0]undec-7-ene cation (DBU) was studied. Interactions between the surface silanol groups of the silica nanoparticles and the ions of these PILs affected the nature of particle aggregation and the hydrogen bonding environment, which was reflected in the nonlinear rheological behaviors and transport properties of their colloidal suspensions. In contrast to shear-thinning gels formed by colloidal suspensions of the silica nanoparticles in [DBU][TFSA] ([TFSA] = [N(SO2CF3)2]), [DBU][TfO] ([TfO] = [CF3SO3]), and [DBU][TFA] ([TFA] = [CF3CO2]), a shear-thickening stable suspension was formed in the [DBU][MSA] ([MSA] = [CH3SO3]) system. A relatively strong interaction between the silanol groups and the ions of [DBU][MSA] and the ability of this PIL to form a thicker solvation layer through hydrogen bonding were assumed to be responsible for this unique behavior. Moreover, the [DBU][MSA]–silica system showed a large enhancement in the conductivity at a certain silica concentration. This enhancement was not observed in the other PIL–silica composites that exhibited shear-thinning behavior. Even though diffusion of ions was found to be restricted in the presence of silica, a preferentially stronger interaction between [MSA] anions and the silica surface resulted in an increase in the number of charge carriers.