Tuning conformational structures of imidazolium ionenes with 1-ethyl-3-methylimidazolium ionic liquid solvents

Journal Article · 25 January 2022 · Chemical Engineering Science

DOI: https://doi.org/10.1016/j.ces.2022.117456 · OSTI ID:1976946

Maurya, Manish ^[1]; Sappidi, Praveenkumar ^[2]; Bara, Jason E. ^[3]; Turner, C. Heath ^[3]

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1. University of Alabama, Tuscaloosa, AL (United States); OSTI
2. Indian Institute of Technology Jodhpur, Jodhpur (India)
3. University of Alabama, Tuscaloosa, AL (United States)

In this report the structures and conformations of imidazolium ionenes solvated in 1-ethyl-3-methylimidazolium ionic liquids (ILs) ([C₂mim⁺][X^-]) are investigated using molecular dynamics simulations. Four different ionenes poly(decylimidazolium) (PD₁₀), poly(tetraethyleneglycolimidazolium) (PE₁₀), alternating copolymer (P(ED)₅), and a block copolymer PE₅D₅ are immersed in [C₂mim⁺][X^-], where [X^-] = thiocyanate [SCN^-], tetrafluoroborate [BF₄^-], and trifluoromethanesulfonate [TfO^-]. The radius of gyration indicates that the ionene chains are more extended when immersed in [TfO^-] compared to [BF₄^-] and [SCN^-], while the solvent accessible surface area shows that PE₁₀ is the most contracted ionene among all systems. The electrostatic interactions between the ionenes and the ILs are very consistent with the inherent electrostatic characteristics of the different anions, which can be quantified using the Ionic Polarity Index (IPI). The ionene configurations and dynamics strongly depend on the backbone functionality and architecture of the chain, due to the balance between the inter- and intra-molecular interactions in these systems.

• Research Organization: University of Alabama, Tuscaloosa, AL (United States); University of South Alabama, Mobile, AL (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC)
• Grant/Contract Number: SC0020282
• OSTI ID: 1976946
• Journal Information: Chemical Engineering Science, Journal Name: Chemical Engineering Science Journal Issue: C Vol. 251; ISSN 0009-2509
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English