Preparation of a natural deep eutectic solvent mediated self polymerized highly flexible transparent gel having super capacitive behaviour

Abstract

2-Hydroxyethyl methacrylate was found to self-polymerize in a natural deep eutectic solvent obtained by the endothermic complexation of choline chloride and orcinol resulting formation of a highly stretchable gel having good capacitive behaviour.

High‐Molecular‐Weight Polyampholytes Synthesized via Daylight‐Induced, Initiator‐Free Radical Polymerization of Renewable Itaconic Acid

“…It is well known that spontaneous thermal radical polymerization at temperature >100 °C is possible for several reactive vinyl monomers, including styrene and acrylic monomers . Moreover, self‐polymerization at room temperature of highly‐reactive 2‐hydroxyethyl methacrylate (HEMA) purified from inhibitor has been reported in choline‐based ionic liquids and DESs, although the polymers have not yet been separated or characterized.…”

Chemically Cross‐Linked Poly(2‐hydroxyethyl methacrylate)‐Supported Deep Eutectic Solvent Gel Electrolytes for Eco‐Friendly Supercapacitors

“…As shown in Figure , following UV‐initiated formation of the DES gel, several peaks associated with the HEMA and PEGDA precursors disappeared from the DES gel sample FTIR spectrum compared with that of the HEMA/PEGDA co‐monomer mixture (30 : 1 molar ratio). Peaks located at 1298 cm −1 and 1320 cm −1 are attributed to vinyl group =CH deformation/wagging, and the peaks found at 810 cm −1 and 1640 cm −1 are due to vinyl =CH bending and C=C stretching vibrations, respectively. The disappearance of these peaks in the DES gel spectrum shown in Figure indicates the complete polymerization of the HEMA and PEGDA co‐monomers within the gel to form a cross‐linked poly(HEMA) (x‐PHEMA) scaffold.…”

“…Recently, Mukesh et al. reported the creation of poly(2‐hydroxyethyl methacrylate), poly(HEMA), homopolymer‐supported DES gels based on a DES containing choline chloride (ChCl) and orcinol and demonstrated their use in supercapacitor prototypes . However, several aspects of these DES gels served to limit their performance as solid electrolytes.…”

“…This result is not unexpected, however, because no chemical (covalent) cross‐links were present within the poly(HEMA) homopolymer scaffold. The combination of such a large polymer content and the highly viscous nature of the ChCl/orcinol DES itself (195 cP at 25 °C; ionic conductivity=2.7 mS cm −1 ) resulted in a low DES gel ionic conductivity (0.24 mS cm −1 ) compared to that exhibited by typical ionogels of comparable stiffness (∼5 mS cm −1 ) . Furthermore, the required gelation time of the self‐polymerized poly(HEMA)‐supported DES gels was at least 1.5 hours .…”

“…The combination of such a large polymer content and the highly viscous nature of the ChCl/orcinol DES itself (195 cP at 25 °C; ionic conductivity=2.7 mS cm −1 ) resulted in a low DES gel ionic conductivity (0.24 mS cm −1 ) compared to that exhibited by typical ionogels of comparable stiffness (∼5 mS cm −1 ) . Furthermore, the required gelation time of the self‐polymerized poly(HEMA)‐supported DES gels was at least 1.5 hours . Thus, there is clearly room to improve upon the solid electrolyte properties of polymer‐supported DES gels (e. g. by obtaining a higher ionic conductivity and an improved modulus with a lower polymer content), which motivated our use of both a chemical cross‐linker as well as a DES known to offer outstandingly low room temperature viscosity/high ionic conductivity (ChCl/ethylene glycol (EG), viscosity=36 cP at 20 °C; ionic conductivity=7.6 mS cm −1 ) in this study.…”