Constructing Ionic Liquid-Filled Proton Transfer Channels within Nanocomposite Membrane by Using Functionalized Graphene Oxide

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• 作者：Wenjia Wu ; Yifan Li ; Pingping Chen ; Jindun Liu ; Jingtao Wang ; Haoqin Zhang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：January 13, 2016
• 年：2016
• 卷：8
• 期：1
• 页码：588-599
• 全文大小：877K
• ISSN：1944-8252

文摘

Herein, nanocomposite membranes are fabricated based on functionalized graphene oxides (FGOs) and sulfonated poly(ether ether ketone) (SPEEK), followed by being impregnated with imidazole-type ionic liquid (IL). The functional groups (acidic group or basic group) on FGOs generate strong interfacial interactions with SPEEK chains and then adjust their motion and stacking. As a result, the nanocomposite membranes possess tunable interfacial domains as determined by its free volume characteristic, which provides regulated location for IL storage. The stored ILs act as hopping sites for water-free proton conduction along the FGO-constructed interfacial channels. The microstructure at SPEEK-FGO interface governs the IL uptake and distribution in nanocomposite membrane. Different from GO and vinyl imidazole functionalized GO (VGO), the presence of acidic (?SO₃H) groups confers the p-styrenesulfonic acid functionalized GO (SGO) incorporated nanocomposite membrane loose interface and strong electrostatic attraction with imidazole-type IL, imparting an enhanced IL uptake and anhydrous proton conductivity. Nanocomposite membrane containing 7.5% SGO attains the maximum IL uptake of 73.7% and hence the anhydrous conductivity of 21.9 mS cm^–1 at 150 °C, more than 30 times that of SPEEK control membrane (0.69 mS cm^–1). In addition, SGOs generate electrostatic attractions to the ILs confined within SGO-SPEEK interface, affording the nanocomposite membrane enhanced IL retention ability.