Počet záznamů: 1
Non-covalent interactions in bmimCl/co-solvent mixtures: a FTIR spectroscopy and computational study
- 1.
SYSNO ASEP 0504639 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Non-covalent interactions in bmimCl/co-solvent mixtures: a FTIR spectroscopy and computational study Tvůrce(i) Kotov, Nikolay (UMCH-V) RID, ORCID
Raus, Vladimír (UMCH-V) RID, ORCID
Dybal, Jiří (UMCH-V) RID, ORCIDZdroj.dok. Journal of Molecular Liquids. - : Elsevier - ISSN 0167-7322
Roč. 285, 1 July (2019), s. 688-696Poč.str. 9 s. Jazyk dok. eng - angličtina Země vyd. NL - Nizozemsko Klíč. slova ionic liquids ; organic electrolyte solutions ; non-covalent interactions Vědní obor RIV CD - Makromolekulární chemie Obor OECD Polymer science CEP GA17-03810S GA ČR - Grantová agentura ČR Způsob publikování Omezený přístup Institucionální podpora UMCH-V - RVO:61389013 UT WOS 000472698800074 EID SCOPUS 85064908096 DOI 10.1016/j.molliq.2019.04.092 Anotace Ionic liquids such as 1-butyl-3-methylimidazolium chloride (bmimCl) are efficient solvents for cellulose, but high viscosity of the resulting solutions hampers further cellulose shaping and derivatization. To solve this problem, mixtures of ILs with various organic co-solvents are often employed in place of neat ILs. So far, the intermolecular interactions in such mixtures are poorly understood, which hinders further development of this class of cellulose solvents. In this work, we utilized infrared spectroscopy (IR) and quantum chemical model calculations to study the intermolecular interactions in differently concentrated mixtures of bmimCl with two typical co-solvents, dimethyl sulfoxide (DMSO) and N,N-dimethylacetamide (DMAc). First, we refined the assignment of the relevant characteristic bands in the IR spectra of the individual mixture components. This then helped us to reveal that bmim+-DMSO and bmim+-DMAc associates, stabilized by hydrogen bonds between the imidazolium ring CH groups and oxygens of DMSO or DMAc, are formed in the studied mixtures. Importantly, only a relatively small fraction of co-solvent molecules (up to ca. 20 mol% for DMSO and ca. 45 mol% for DMAc) are involved in the associate formation, leaving a large proportion of bmimCl molecules non-solvated. While the maximum co-solvent concentration at which direct cellulose dissolution can be achieved is considerably different for DMSO and DMAc, the corresponding molar ratio of bmimCl to interacting co-solvent molecules was the same for both the studied systems (about 2.5:1). We propose that this ratio might be related to the critical size of bmimCl clusters necessary for achieving cellulose dissolution. Furthermore, increasing the temperature from 25 to 80 °C resulted in a significantly decreased fraction of interacting solvent molecules for bmimCl/DMSO but not for bmimCl/DMAc. This indicates that the comparatively lower tendency of DMSO to form associates with bmimCl is due to the lower strength of the underlying hydrogen bond. The results of this study illustrate how intermolecular interactions influence the macroscopic performance of different IL-based solvent systems. Pracoviště Ústav makromolekulární chemie Kontakt Eva Čechová, cechova@imc.cas.cz ; Tel.: 296 809 358 Rok sběru 2020 Elektronická adresa https://www.sciencedirect.com/science/article/pii/S0167732219301898?via%3Dihub
Počet záznamů: 1