Proton Conducting Membranes Based on Poly(Ionic Liquids) Having Phosphonium Counter‐Cations

Abstract

Proton conducting polymeric membranes are highly searched in many different technologies ranging from energy to biosensing. Protic ionic liquids and their polymeric version represent a new family of proton conducting molecules with relatively facile synthesis and excellent properties. In this work, protic poly(ionic liquids) having the most popular phosphonium counter-cations are presented for the first time. The synthesis is carried out through proton transfer reactions or through ion exchange reactions by using commercially available tertiary phosphines. Tributyl-, trioctyl-, and tricyclohexyl-phosphine are selected to form the desired cations. Polystyrene sulfonic acid, poly(2-acrylamido-2-methyl-1-propanesulfonic acid), and lithium poly[(4-styrenesulfonyl) (trifluoromethanesulfonyl)imide] polymers are used to form the polymeric anions. The chemical structure of the protic poly(ionic liquids) is confirmed by spectroscopic characterizations such as Fourier transform infrared and nuclear magnetic resonance spectroscopies. Thermal properties of the polymer are characterized by means of differential scanning calorimetry and thermogravimetric analysis. Polymers exhibit good membrane forming ability as well as high ionic conductivities in the range of 10 to 10 S cm from 30 to 90 °C.

Influence of Counteranion on the Properties of Polymerized Ionic Liquids/Ionic Liquids Proton-Exchange Membranes

“…Novel protic polyILs containing phosphonium cations and different polymer backbones have been synthesized successively in the study of Mecerreyes and co-workers. 16 They demonstrated that a lower glass-transition temperature can be achieved using a longer and mobile polymer side chain, and/or a long alkyl chain in cations, resulting in a high conductivity of about 2 × 10 −4 S/cm at 150 °C. Zhu and co-workers found that polyILs are capable of forming nanoscale interconnecting channels because of the highly dissociable cations, leading to a high anhydrous proton conductivity of 3.1 × 10 −4 S/cm at 120 °C, among the highest conductivities reported for neat polymers so far.…”

“…PolyILs have been endowed with excellent and tunable properties because of the inimitable combination of counterions and polymers, drawing burgeoning interest in the field of proton-conducting membranes. Novel protic polyILs containing phosphonium cations and different polymer backbones have been synthesized successively in the study of Mecerreyes and co-workers . They demonstrated that a lower glass-transition temperature can be achieved using a longer and mobile polymer side chain, and/or a long alkyl chain in cations, resulting in a high conductivity of about 2 × 10 –4 S/cm at 150 °C.…”

Cation Effect in the Corrosion Inhibition Properties of Coumarate Ionic Liquids and Acrylic UV-Coatings

“…One way to achieve this is to polymerize the inhibiting moiety into the coating by developing monomeric ionic liquid inhibitors. Therefore, we have initiated a program on the development of poly(ionic liquid)s corrosion inhibitors as a new application for this emerging family of functional polymers which are finding applications in emerging technologies, such as batteries, (bio)electronics, gas separation membranes, or water purification [20][21][22][23][24].…”

Stable poly (ionic liquids) with unique cross‐linked mesoporous‐macroporous structure as efficient catalyst for alkylation of o‐xylene and styrene

“…Thus, based on previous studies of PILs, novel multi‐monomer PILs were studied by chemists, and exhibited applications in numerous areas, such as: bacteriophage purification, polymer electrolytes, organic synthesis, self‐assembly, membrane, absorption, etc. Liu et al .…”