Work

The molecular nature of the eliminating azeotropy in water–acetonitrile system by ionic liquid entrainer using FTIR and DFT calculations

Year: 2024

Type: article

Abstract: This study focused on investigating the structure and hydrogen-bonding characteristics of 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc])-water-acetonitrile mixtures aiming at revealing the molecular intrinsic of the azeotropy breaking by ionic liquid entrainer. Our approach combined FTIR with density functional theory (DFT) calculations applying the C N stretching vibration region as the responsive indicator of the microenvironment to discern the structural and hydrogen-bonding properties of the H 2 O‒CH 3 CN and [EMIM][OAc]‒CH 3 CN binary systems and [EMIM][OAc]−H 2 O−CH 3 CN ternary systems. Distinct interaction models were observed between [EMIM][OAc] and CH 3 CN compared to those in water and CH 3 CN system, leading to different influences on the C N stretching vibration region. Excess peaks associated with H 2 O−CH 3 CN, CH 3 CN self-aggregator, and IL−CH 3 CN interaction complexes were identified. The interaction strength between [EMIM][OAc] and CH 3 CN was notably more potent than that between water and CH 3 CN. Consequently, IL had the ability to disrupt the interaction complex of water-acetonitrile with the formation of the IL−CH 3 CN complex. This species transformation during the mixing process elucidated the characteristics of phase equilibrium shift in the azeotrope system.

Source: Journal of Molecular Structure

DOI: 10.1016/j.molstruc.2024.140934

Authors: Yan-Zhen Zheng, Rui Zhao, Shu-Yan Liu, Xiu-Yu Du, Yu Zhou

Institutions: Jimei University, Qingdao University

Language: English

Topic: Ionic liquids properties and applications

Subfield: Catalysis

Field: Chemical Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,570

Funders: National Natural Science Foundation of China, Natural Science Foundation of Fujian Province