What is the effect of polar and nonpolar side chain group on bulk and electrical double layer properties of amino acid ionic liquids?

Two amino acid ionic liquids (AAILs) were investigated by molecular dynamics simulation to get effect of polar group at bulk of liquid and adsorb layer of electric double layer. Hydrogen bond plays an important role in this evaluation. Polar group changed hydrogen bond site of the pure bulk. By introducing AAILs on the graphene surface, the total number of hydrogen bonds was increased and hydrogen bond site was changed in the case of common ionic liquid. It was also observed anion-anion self-hydrogen bond is probable for AAILs. Graphene surface decreases the number of this self-hydrogen bonds. Potential of mean force was also obtained to find adsorption or desorption free energy of AAILs near the surface. The interaction of anion with the surface is weakened if anion of AAIL contains polar group. Responsing with lower potential is an important factor in using an IL as an electrolyte in supercapacitors. Polar group decreases the response potential of the AAIL.