Changes in the Coherent Dynamics of Nanoconfined Room Temperature Ionic Liquids

POSTER

Abstract

Confinement and temperature effects on the coherent dynamics of the room temperature ionic liquid (RTIL) [C$_{10}$MPy$^{+}$] [Tf$_{2}$N$^{-}$] were investigated using neutron spin-echo (NSE) in two silica matrices with different pore size. Several intermolecular forces give rise to the bulk molecular structure between anions and cations. NSE provided dynamics (via the coherent intermediate scattering function) in the time range of 0.004 to 10 ns, and at Q-values corresponding to intermediate range ordering and inter- and intra-molecular length scales of the RTIL. Pore wall effects were delineated by comparing bulk RTIL dynamics with those of the confined fluid in 2.8 nm and 8 nm pores. Analytical models were applied to the experimental data to extract decay times and amplitudes of each component. We find a fast relaxation outside the experiment time window, a primary relaxation, and slow, surface-induced dynamics, which all speed up with increased temperature, however, the temperature dependence differs between bulk and confinement. This study sheds light on the structure and dynamics of RTILs and is relevant to the optimization of RTILs for green technologies and applications.

Authors

  • Kevin Vallejo

    The University of Texas at El Paso

  • Melissa Cano

    The University of Texas at El Paso

  • William Stockwell

    Logan High School, University of Tsukuba, Department of Physics, University of Texas at El Paso, El Paso, TX, Division of Engineering, Mayo Clinic, Rochester, MN, Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, Utah Valley University, University of New Mexico, Brigham Young University, Moxtek, INC, New Mexico State University, Oak Ridge National Laboratory, Oak Ridge TN 37830, USA, Los Alamos National Laboratory, Argonne National Laboratory, Embry-Riddle Aeronautical University, University of Newcastle, University of Sydney, Brigham Young University Provo, Rice University, Perimeter Institute and University of Guelph, University of Reims Champagne-Ardenne, France, Texas A&M University, University of Illinois at Urbana-Champaign, University of Valencia, Spain, None, University of Texas at El Paso, Universidad Simon Bolivar, Universidad Autonoma de Ciudad Juarez, Brigham Young University - Provo, Morgan High School - Morgan, UT, Utah State University, University of Tsukaba, Chemistry Research Center, US Air Force Academy, USAFA, JILA, University of Colorado Boulder, Department of Physics, Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX, Department of Orthopedics, Mayo Clinic, Rochester, MN, Colorado State University, National Research Tomsk Polytechnic University \& New Mexico State University,, National Institute of Standards and Technology Center for Neutron Research, Oak Ridge National Laboratory, Huazhong University of Science and Technology, U of Utah, NMSU, Division of Engineering, Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA, INM - Leibniz Institute for New Materials, Saarbrucken, Germany, Department of Physics, The University of Texas at El Paso, El Paso, Texas, 7996, UTEP, Arizona State University, The University of Texas at El Paso, none, National Renewable Energy Laboratory, Division of Engineering, Department of Neurologic Surgery, Mayo Clinic, Department of Physics, Border Biomedical Research Center, University of Texas at El Paso, Division of Engineering, Mayo Clinic, Department of Neurologic Surgery, Mayo Clinic, Department of Physics & Astronomy, Texas A&M University, Commerce,TX-75428, USA., INFN, Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy, Texas A&M University Commerce, Commerce, Texas-75429, Department of Physics and Astronomy, Texas A&M University-Commerce, Commerce, Texas 75429, USA, Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA, Department of Physics, University of Texas at El Paso, University of Delaware, IIT INDORE, UT AUSTIN, Idaho Accelerator Center, Brigham Young University, Physics and Astronomy, Univesidad de Guanajuato, Fermilab, École Polytechnique Fédérale de Lausanne, RadiaSoft, LLC, Weber State University, University of Texas at Dallas, National High Magnetic Field Laboratory, University of Texas Southwestern Medical Center, University of Alabama in Huntsville, Marshall Space Flight Center, NASA, Howard University

  • William Stockwell

    Logan High School, University of Tsukuba, Department of Physics, University of Texas at El Paso, El Paso, TX, Division of Engineering, Mayo Clinic, Rochester, MN, Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, Utah Valley University, University of New Mexico, Brigham Young University, Moxtek, INC, New Mexico State University, Oak Ridge National Laboratory, Oak Ridge TN 37830, USA, Los Alamos National Laboratory, Argonne National Laboratory, Embry-Riddle Aeronautical University, University of Newcastle, University of Sydney, Brigham Young University Provo, Rice University, Perimeter Institute and University of Guelph, University of Reims Champagne-Ardenne, France, Texas A&M University, University of Illinois at Urbana-Champaign, University of Valencia, Spain, None, University of Texas at El Paso, Universidad Simon Bolivar, Universidad Autonoma de Ciudad Juarez, Brigham Young University - Provo, Morgan High School - Morgan, UT, Utah State University, University of Tsukaba, Chemistry Research Center, US Air Force Academy, USAFA, JILA, University of Colorado Boulder, Department of Physics, Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX, Department of Orthopedics, Mayo Clinic, Rochester, MN, Colorado State University, National Research Tomsk Polytechnic University \& New Mexico State University,, National Institute of Standards and Technology Center for Neutron Research, Oak Ridge National Laboratory, Huazhong University of Science and Technology, U of Utah, NMSU, Division of Engineering, Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA, INM - Leibniz Institute for New Materials, Saarbrucken, Germany, Department of Physics, The University of Texas at El Paso, El Paso, Texas, 7996, UTEP, Arizona State University, The University of Texas at El Paso, none, National Renewable Energy Laboratory, Division of Engineering, Department of Neurologic Surgery, Mayo Clinic, Department of Physics, Border Biomedical Research Center, University of Texas at El Paso, Division of Engineering, Mayo Clinic, Department of Neurologic Surgery, Mayo Clinic, Department of Physics & Astronomy, Texas A&M University, Commerce,TX-75428, USA., INFN, Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy, Texas A&M University Commerce, Commerce, Texas-75429, Department of Physics and Astronomy, Texas A&M University-Commerce, Commerce, Texas 75429, USA, Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA, Department of Physics, University of Texas at El Paso, University of Delaware, IIT INDORE, UT AUSTIN, Idaho Accelerator Center, Brigham Young University, Physics and Astronomy, Univesidad de Guanajuato, Fermilab, École Polytechnique Fédérale de Lausanne, RadiaSoft, LLC, Weber State University, University of Texas at Dallas, National High Magnetic Field Laboratory, University of Texas Southwestern Medical Center, University of Alabama in Huntsville, Marshall Space Flight Center, NASA, Howard University

  • William Stockwell

    Logan High School, University of Tsukuba, Department of Physics, University of Texas at El Paso, El Paso, TX, Division of Engineering, Mayo Clinic, Rochester, MN, Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, Utah Valley University, University of New Mexico, Brigham Young University, Moxtek, INC, New Mexico State University, Oak Ridge National Laboratory, Oak Ridge TN 37830, USA, Los Alamos National Laboratory, Argonne National Laboratory, Embry-Riddle Aeronautical University, University of Newcastle, University of Sydney, Brigham Young University Provo, Rice University, Perimeter Institute and University of Guelph, University of Reims Champagne-Ardenne, France, Texas A&M University, University of Illinois at Urbana-Champaign, University of Valencia, Spain, None, University of Texas at El Paso, Universidad Simon Bolivar, Universidad Autonoma de Ciudad Juarez, Brigham Young University - Provo, Morgan High School - Morgan, UT, Utah State University, University of Tsukaba, Chemistry Research Center, US Air Force Academy, USAFA, JILA, University of Colorado Boulder, Department of Physics, Border Biomedical Research Center, University of Texas at El Paso, El Paso, TX, Department of Orthopedics, Mayo Clinic, Rochester, MN, Colorado State University, National Research Tomsk Polytechnic University \& New Mexico State University,, National Institute of Standards and Technology Center for Neutron Research, Oak Ridge National Laboratory, Huazhong University of Science and Technology, U of Utah, NMSU, Division of Engineering, Department of Neurologic Surgery, Mayo Clinic, Rochester, MN, Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA, INM - Leibniz Institute for New Materials, Saarbrucken, Germany, Department of Physics, The University of Texas at El Paso, El Paso, Texas, 7996, UTEP, Arizona State University, The University of Texas at El Paso, none, National Renewable Energy Laboratory, Division of Engineering, Department of Neurologic Surgery, Mayo Clinic, Department of Physics, Border Biomedical Research Center, University of Texas at El Paso, Division of Engineering, Mayo Clinic, Department of Neurologic Surgery, Mayo Clinic, Department of Physics & Astronomy, Texas A&M University, Commerce,TX-75428, USA., INFN, Sezione di Pisa, Largo Pontecorvo 3, 56127 Pisa, Italy, Texas A&M University Commerce, Commerce, Texas-75429, Department of Physics and Astronomy, Texas A&M University-Commerce, Commerce, Texas 75429, USA, Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA, Department of Physics, University of Texas at El Paso, University of Delaware, IIT INDORE, UT AUSTIN, Idaho Accelerator Center, Brigham Young University, Physics and Astronomy, Univesidad de Guanajuato, Fermilab, École Polytechnique Fédérale de Lausanne, RadiaSoft, LLC, Weber State University, University of Texas at Dallas, National High Magnetic Field Laboratory, University of Texas Southwestern Medical Center, University of Alabama in Huntsville, Marshall Space Flight Center, NASA, Howard University

  • Jose L. Bañuelos

    University of Texas El Paso, The University of Texas at El Paso, University of Texas at El Paso