Molecular insights of poly (benzyl acrylate) in ionic liquid–water mixture using all atom molecular dynamics simulations

Acrylic polymer poly(benzyl acrylate) (PBA) is an interesting versatile polymer for various industrial applications. Understanding the conformational transitions of the PBA in various solvent mixtures is challenging. In this paper, we present an all-atom molecular dynamics simulation study to understand the inter and intra-molecular structural properties of the PBA in the ionic liquid (IL)–water mixture. We have considered 1-ethyl-3-methyl imidazolium bistriflimide ([EMIM] ⁺ [BIS]⁻) as (IL) in the aqueous mixture with the concentration of IL varying from 0.44 to 2.2 M. Various conformational and structural properties were analysed such as radius of gyration (R_g), end-to-end distance (R), radial distribution functions (RDF), reduced density gradient (RDG), solvent-accessible surface area (SASA) and Hydrogen bonding. The PBA chain shows a compact-like structure in the lower IL concentration and coiled conformation at higher IL concentration. The <i>R_g</i> value shows an increment till a specific IL concentration value, then shows a decrease. The corresponding RDF analysis shows higher anion–cation interactions, whereas PBA-IL interactions decrease with increase in IL concentration. The RDG and Hydrogen bonding provided detailed molecular-level insights about the non-covalent interactions between the PBA and ILs. The results presented in the manuscript will help to understand the design of polymers and IL composite materials.