PVDF based ionogels: applications towards electrochemical devices and membrane separation processes

Abstract

Ionogels have emerged as one of the most interesting and captivating form of composites which credits to the outstanding characteristics. One of the most important constituent of ionogels is ionic liquid, which show many attractive properties notably non-volatility, in-flammability, negligible vapor pressure, tunability, thermal stability and solvating ability. A large variety of matrix materials have been under consideration for ionogels, presently, polymer/ionic liquid based ionogels have attracted much attention. Numerous polymeric materials such as have been utilized for these polymer/ionic liquids based ionogels. Polyvinylidene fluoride (PVDF) has been on top of the line as a matrix material for polymer based ionogels owing to its stability, aging and chemical resistance and mechanical strength. This review is primarily concerned with the properties of polyvinylidene fluoride based ionogels with an emphasis on their applications in various domains electrochemical devices, gas separation and liquid/liquid separations.

Highly Stretchable, Fast Self-Healing, and Waterproof Fluorinated Copolymer Ionogels with Selectively Enriched Ionic Liquids for Human-Motion Detection

“…A fluorinated polymer is a highly desired polymer matrix for fabricating ionogels because of its low surface energy, high humidity insensitivity, and excellent thermal/chemical stability originating from the highly electronegative fluorine atoms and strong C–F bonds. − Among a variety of fluorinated polymers, thermoplastic polymers like polyvinylidene fluoride (PVDF) and poly­(vinylidene fluoride- co -hexafluoropropylene) (PVDF- co -HFP) are commonly used due to their electroactivity and easy processibility. Nevertheless, the rigid crystalline regions among PVDF lead to poor deformation-tolerant and self-healing performance, severely reducing the durability and reliability of the resultant ionogels. , Furthermore, the improvements in the stretchability of ionogels have been achieved through increasing the loading of ILs, but this will undoubtedly result in the leakage of ILs. Therefore, the achievement of fluorinated ionogels with ultrastretchability, solvent-retention capacity, fast self-healability, and waterproofness is greatly desired for next-generation i-skins.…”

“…Nevertheless, the rigid crystalline regions among PVDF lead to poor deformation-tolerant and self-healing performance, severely reducing the durability and reliability of the resultant ionogels. 31,32 Furthermore, the improvements in the stretchability of ionogels have been achieved through increasing the loading of ILs, but this will undoubtedly result in the leakage of ILs. Therefore, the achievement of fluorinated ionogels with ultrastretchability, solvent-retention capacity, fast self-healability, and waterproofness is greatly desired for nextgeneration i-skins.…”

Ionomers Based on Addition and Ring Opening Metathesis Polymerized 5-phenyl-2-norbornene as a Membrane Material for Ionic Actuators

“…ILs have unique and advantageous properties such as high ionic conductivity, thermal stability, wide electrochemical window, and immeasurably low vapor pressure. Polymer gel electrolytes based on ILs demonstrate conductivity at a room temperature above 10 −3 S/cm, which is enough for practical use [ 26 ]. High efficiency of carbon nanotubes-based electrodes (bucky gel electrodes) in actuators comprising ionic liquid was shown by Asaka [ 25 , 27 , 28 ].…”

Effect of Different Pore-Forming Additives on the Formation of PVDF Microporous Membranes for Bucky-Gel Actuator

“…The high ionic conductivity, thermal and chemical stability, a wide electrochemical window are the unique properties of ionic liquids (ILs), making them a good alternative to aqueous or solid electrolytes to prepare PGEs. Polymer gel electrolytes based on IL demonstrate room temperature conductivity above 10 -3 S/cm, which is enough for practical use [25]. The simplest way to produce PVDF membrane for electroactive polymer actuators is the conventional dry-casting process [26].…”