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In the past two decades, ionic liquids (ILs) have blossomed as versatile task-specific materials with a unique combination of properties, which can be beneficial for a plethora of different applications. The additional need of incorporating ILs into solid devices led to the development of a new class of ionic soft-solid materials, named here iongels. Nowadays, iongels cover a wide range of materials mostly composed of an IL component immobilized within different matrices such as polymers, inorganic networks, biopolymers or inorganic nanoparticles. This review aims at presenting an integrated perspective on the recent progress and advances in this emerging type of material. We provide an analysis of the main families of iongels and highlight the emerging types of these ionic soft materials offering additional properties, such as thermoresponsiveness, self-healing, mixed ionic/electronic properties, and (photo)luminescence, among others. Next, recent trends in additive manufacturing (3D printing) of iongels are presented. Finally, their new applications in the areas of energy, gas separation and (bio)electronics are detailed and discussed in terms of performance, underpinning it to the structural features and processing of iongel materials.

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 -8 to 10 -3 S cm -1 from 30 to 90 °C., (© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We demonstrate the fabrication of polymer thin-film transistors gated with an ion gel electrolyte made of the blend of an ionic liquid and a polymerised ionic liquid. The ion gel exhibits a high stability and ionic conductivity, combined with facile processing by simple drop-casting from solution. In order to avoid parasitic effects such as high hysteresis, high off-currents, and slow switching, a fluorinated photoresist is employed in order to enable high-resolution orthogonal patterning of the polymer semiconductor over an area that precisely defines the transistor channel. The resulting devices exhibit excellent characteristics, with an on/off ratio of 106, low hysteresis, and a very large transconductance of 3 mS. We show that this high transconductance value is mostly the result of ions penetrating the polymer film and doping the entire volume of the semiconductor, yielding an effective capacitance per unit area of about 200 µF cm-2, one order of magnitude higher than the double layer capacitance of the ion gel. This results in channel currents larger than 1mA at an applied gate bias of only -1 V. We also investigate the dynamic performance of the devices and obtain a switching time of 20 ms, which is mostly limited by the overlap capacitance between the ion gel and the source and drain contacts. [ABSTRACT FROM AUTHOR]