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Title: Exploring the Use of Ionic Liquid Mixtures to Enhance the Performance of Dicationic Ionic Liquids

Dicationic ionic liquids (DILs) of diverse structural architectures (including symmetrical and asymmetrical ammonium, phosphonium and heterodications and the bis(trifluoromethylsulfonyl)amide (NTf 2 -) anion) have been prepared and used as additives to N-methyl-N-ethoxyethylpyrrolidinium (P 1EOE) NTf 2, a relatively high-performing IL in terms of its transport properties (viscosity 53 mPa s). The three-ion, binary IL mixtures were characterized for their thermal and transport properties using differential scanning calorimetry, temperature dependent viscosity, conductivity and Pulsed Gradient Spin Echo (PGSE) NMR. Variable temperature 1H, 19F and 31P self-diffusion coefficients were determined at 25, 60 and 75°C. The order of the diffusion coefficients was D(P 1EOE +) > D(anion) > D(dication), and the composition of the dication had a strong effect on the degree to which diffusion of all three species is more or less coupled. IL mixtures containing about 30 mol % of the dicationic NTf 2 and 70 mol % of P 1EOE NTf 2 resulted in a significant decrease in glass transition temperatures and viscosities compared to the pure DIL. The mixtures extended the liquid range and potential for practical applications significantly. Finally, the data obtained here provides insight into the future design of dicationic salts tailored to exhibit lower viscositymore » and higher conductivities.« less
 [1] ;  [2] ;  [3] ;  [3] ;  [3] ;  [4] ;  [5] ;  [6] ;  [6]
  1. Queensborough Community College, Bayside, NY (United States). Dept. of Chemistry
  2. Brooklyn College, Brooklyn, NY (United States). Physics Dept.
  3. Queensborough Community College of the City Univ. of New York, Bayside, NY (United States). Dept. of Chemistry
  4. Hunter College, New York, NY (United States). Dept. of Physics
  5. Univ. of Kelaniya (Sri Lanka). Dept. of Physics
  6. Brookhaven National Lab. (BNL), Upton, NY (United States). Chemistry Division
Publication Date:
Report Number(s):
Journal ID: ISSN 0013-4651; R&D Project: CO-004; KC0301010
Grant/Contract Number:
SC0012704; 68132-00 46
Accepted Manuscript
Journal Name:
Journal of the Electrochemical Society
Additional Journal Information:
Journal Volume: 164; Journal Issue: 8; Journal ID: ISSN 0013-4651
The Electrochemical Society
Research Org:
Brookhaven National Lab. (BNL), Upton, NY (United States); Queensborough Community College, Bayside, NY (United States); Hunter College, New York, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Science (SC), Workforce Development for Teachers and Scientists (WDTS) (SC-27); National Science Foundation (NSF); National Inst. of Health (NIH) (United States); Staff Congress of the City Univ. of New York (PSC-CUNY) (United States)
Contributing Orgs:
Brooklyn College, Brooklyn, NY (United States); Univ. of Kelaniya (Sri Lanka)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Asymmetrical; conductivity; Dicationic; Diffusion Coefficient; DSC; Ionic Liquids; Mixtures; NMR; PGSE
OSTI Identifier: