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Polymer-grafted nanoparticles, ionic liquid, conductivity, solvation, imaging
Abstract:
Polymer-grafted nanoparticles stabilized in ionic liquid (IL)-solvent mixtures are investigated using transmission electron microscopy, dynamic light scattering and electrochemical impedance spectroscopy. The ionic conductivity of IL/solvent mixtures with the polymer-grafted nanoparticles is found to be higher than nanoparticles in the IL. These particles offer additional interactions between polymer and IL, which can mitigate solvation in ILs with solvents. Motivated by this, we present the conductivity data of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HMIM-TFSI) with PMMA-grafted particles in good and bad solvents and further discuss how graft density influences the swelling of PMMA and solvation characteristics of HMIM-TFSI. We found that HMIM-TFSI/acetonitrile containing high grafting density particles has higher conductivity than HMIM-TFSI/methanol mixture with grafted particles. Thus, solubility of PMMA in acetonitrile and preferential interactions between PMMA/HMIM-TFSI are shown to govern the swelling, solvation and conductive properties of IL with the polymer-grafted nanoparticles.