Jose L Banuelos | University of Texas at El Paso (UTEP) (original) (raw)
Papers by Jose L Banuelos
International Journal of Smart and Nano Materials, 2021
ABSTRACT Recent studies have highlighted the effects of various stimuli on the chemical reduction... more ABSTRACT Recent studies have highlighted the effects of various stimuli on the chemical reduction of graphene oxide (GO) through green reductant L-ascorbic acid (L-AA); however, the combination of near ultraviolet (NUV) light to increase the reduction rate has yet to be thoroughly explored. In this study, drop-casted GO films were subjected to chemical reduction through L-AA with various levels of exposure under 405 nm NUV radiation. The structure and uniformity of GO stackings that form the film were characterized through scanning electron microscopy (SEM) and wide-angle x-ray scattering (WAXS). Additionally, WAXS was used to track the removal of oxygen-containing functional groups along with Fourier-transform infrared (FT-IR) spectroscopy and x-ray photoelectron spectroscopy (XPS) as a function of L-AA and NUV light exposure times. XPS results demonstrated that the interaction between L-AA and NUV exposure has a significant effect on the reduction of films. Furthermore, the results that yielded the highest reduction (C-C bond concentration of 60.7%) were the longest L-AA and NUV light exposure times (48 hours and 3 hours, respectively). This report provides a study on the effects of NUV on the green reduction of GO films through L-AA with potential application in solar energy and chemical sensing applications. Graphical abstract
Bulletin of the American Physical Society, 2020
Bulletin of the American Physical Society, 2019
Bulletin of the American Physical Society, 2020
Physical Chemistry Chemical Physics, 2020
Multidisciplinary experimental and theoretical study highlighting the molecular-scale structural ... more Multidisciplinary experimental and theoretical study highlighting the molecular-scale structural and dynamic properties of CO2 capture solvents during a temperature-, time- and CO2-loading-dependent metastable/glassy transition.
ACS central science, Jan 22, 2018
Understanding the origins of lipid membrane bilayer rearrangement in response to external stimuli... more Understanding the origins of lipid membrane bilayer rearrangement in response to external stimuli is an essential component of cell biology and the bottom-up design of liposomes for biomedical applications. The enzymes phospholipase C and D (PLC and PLD) both cleave the phosphorus-oxygen bonds of phosphate esters in phosphatidylcholine (PC) lipids. The atomic position of this hydrolysis reaction has huge implications for the stability of PC-containing self-assembled structures, such as the cell wall and lipid-based vesicle drug delivery vectors. While PLC converts PC to diacylglycerol (DAG), the interaction of PC with PLD produces phosphatidic acid (PA). Here we present a combination of small-angle scattering data and all-atom molecular dynamics simulations, providing insights into the effects of atomic-scale reorganization on the supramolecular assembly of PC membrane bilayers upon enzyme-mediated incorporation of DAG or PA. We observed that PC liposomes completely disintegrate in ...
Research Summary: An increase of the alkyl chain length of the cation of room temperature ionic l... more Research Summary: An increase of the alkyl chain length of the cation of room temperature ionic liquids (RTILs) influences the nanoscale structure and dynamics of RTILs, which in turn affect the behavior of RTILs at solid-liquid interfaces central to energy storage devices. We integrate classical molecular dynamics (CMD) simulation, fluorescence correlation spectroscopy (FCS), time resolved fluorescence anisotropy decay (TRFAD,) small angle X-ray scattering (SAXS) and nuclear magnetic resonance (NMR) to investigate the fundamental properties including structure, dynamics and interfacial behavior of RTIL electrolytes. We found that the elongation of the alkyl chain in the cation gives rise to an enhanced spatial and dynamical heterogeneity, which have been observed in CMD, FCS, TRFAD and SAXS; CMD combined with NMR has revealed the weak temperature dependence of the dynamics of RTILs at a silica surface due to the surface roughness and strong interaction between the ions and silica w...
Soft Matter, 2021
Nanoconfinement of ionic liquids (ILs) influences their physicochemical properties.
Polymer, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Water Process Engineering, 2019
Abstract We report the ZnO nanoparticle-templated formation of nanoporous carbon (NTC) embedded w... more Abstract We report the ZnO nanoparticle-templated formation of nanoporous carbon (NTC) embedded with TiO2 nanoparticles for the adsorption and photodegradation of organic pollutants in water. Small-angle X-ray scattering (SAXS) studies indicate that NTC and NTC-TiO2 exhibit two types of porosities with average pore diameters of 2.8 and 11.5 nm, while Brunauer-Emmet-Teller (BET) surface area analysis revealed the surface area of 302 and 230 m2/g, respectively. These materials exhibit fast adsorption kinetics against methylene blue, ofloxacin, and tetracycline in water. Exposure of NTC-TiO2 to UV-light results in higher contaminant adsorption due to the active photodegradation which prevents the saturation of the nanocomposite.
ABSTRACT Breakthroughs in the performance of energy storage technologies come from efficient comb... more ABSTRACT Breakthroughs in the performance of energy storage technologies come from efficient combinations of novel electrolytes and electrode materials. Knowledge of the structure of these materials under applied electric fields is necessary to better tailor them to our energy needs. Neutron scattering, as a structural probe to investigate the ordering of electrolytes at an interface, or the effects of confinement on an electrolyte in a nanoporous matrix, is well suited since the electrolytes commonly used contain hydrogen and the host matrix can often contain active sites that are difficult to discern without the use of contrast matching via isotopic substitution. We present small angle neutron scattering results, conducted at the EQ-SANS (ORNL) instrument and at the Low-Q Diffractometer (LANL), from in situ electrochemical measurements of a deuterated ionic liquid, and of aqueous electrolytes, in a mesoporous carbon membrane at different applied potentials over time. Recent neutron reflectometry measurements (LR, SNS) complement the observed behavior from SANS. We observe a higher electrolyte density near the electrode material surface, compared to without an applied potential. Furthermore, this high density region persists long after the applied potential is removed.
The Journal of Physical Chemistry C, 2013
Review of Scientific Instruments, 2012
A new high-pressure cell design for use in neutron reflectometry (NR) for pressures up to 50 MPa ... more A new high-pressure cell design for use in neutron reflectometry (NR) for pressures up to 50 MPa and a temperature range of 300-473 K is described. The cell design guides the neutron beam through the working crystal without passing through additional windows or the bulk fluid, which provides for a high neutron transmission, low scattering background, and low beam distortion. The o-ring seal is suitable for a wide range of subcritical and supercritical fluids and ensures high chemical and pressure stability. Wafers with a diameter of 5.08 cm (2 in.) and 5 mm or 10 mm thickness can be used with the cells, depending on the required pressure and momentum transfer range. The fluid volume in the sample cell is very small at about 0.1 ml, which minimizes scattering background and stored energy. The cell design and pressure setup for measurements with supercritical fluids are described. NR data are shown for silicon/silicon oxide and quartz wafers measured against air and subsequently within the high-pressure cell to demonstrate the neutron characteristics of the high-pressure cell. Neutron reflectivity data for supercritical CO(2) in contact with quartz and Si/SiO(2) wafers are also shown.
The Journal of Physical Chemistry Letters, 2012
Molecular dynamics (MD) simulations of 1-alkyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl... more Molecular dynamics (MD) simulations of 1-alkyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([C n MPy][Tf 2 N], n = 3, 4, 6, 8, 10) were conducted using an all-atom model. Radial distribution functions (RDF) were computed and structure functions were generated to compare with new X-ray scattering experimental results, reported herein. The scattering peaks in the structure functions generally shift to lower Q values with increased temperature for all the liquids in this series. However, the first sharp diffraction peak (FSDP) in the longer alkyl chain liquids displays a marked shift to higher Q values with increasing temperature. Alkyl chain-dependent ordering of the polar groups and increased tail aggregation with increasing alkyl chain length were observed in the partial pair correlation functions and the structure functions. The reasons for the observed alkyl chaindependent phenomena and temperature effects were explored.
... Authors: Jacob Urquidi (New Mexico State University). Jose L. Banuelos (New Mexico State Univ... more ... Authors: Jacob Urquidi (New Mexico State University). Jose L. Banuelos (New Mexico State University). ... SANS has been used to characterize the shape, size and polydispersity of these reverse micelle systems which are macroscopically clear but nanoscopically heterogeneous. ...
Aps Meeting Abstracts, Mar 1, 2009
ABSTRACT The ability of proteins to change their conformation in response to changes in their env... more ABSTRACT The ability of proteins to change their conformation in response to changes in their environment has consequences in biological processes like metabolism, chemical regulation in cells, and is believed to play a role in the onset of several neurodegenerative diseases. Factors such as concentration, degree of crowding from other entities, and solvent medium affect how a protein folds. As a protein unfolds, the ratio of nonpolar to polar groups exposed to water changes, affecting a protein's thermodynamic properties. Using small angle x-ray scattering (SAXS), we are currently studying the intermediate protein conformations that arise during the folding/unfolding process as a function of temperature for a series of globular proteins. The temporal stability of these ensembles is also under investigation. Trends in the scattering profiles, along with correlations with protein thermodynamics, may help elucidate shared characteristics between all proteins in their folding behavior.
Molecular dynamics simulations were performed on piperidinium-based ([C4mpip+][Tf2N-]) and pyrrol... more Molecular dynamics simulations were performed on piperidinium-based ([C4mpip+][Tf2N-]) and pyrrolidinium-based ([Cnmpy+]][Tf2N-], n=3, 4, 6, 8, 10) ionic liquids at 1 atm over a wide range of temperatures. The temperature-dependent transport properties of free ionic liquids, including diffusion coefficients and reorientational correlation time were calculated and were found to agree very well with the results measured in NMR and Fluorescence anisotropy experiments. The computed small angle X-ray structure factors of ([Cnmpy+]][Tf2N-] at varying temperatures exhibited a good agreement with the corresponding SAXS experimental results. Spatial heterogeneity of ([Cnmpy+]][Tf2N-] was also investigated. With the alkyl chain length increasing, the diffusion was slower. Additionally, the tail-tail radial distribution function showed that as the alkyl chain length increases, the nanoaggregation of cations becomes more significant. This result was also proved in the SAXS experiments.
International Journal of Smart and Nano Materials, 2021
ABSTRACT Recent studies have highlighted the effects of various stimuli on the chemical reduction... more ABSTRACT Recent studies have highlighted the effects of various stimuli on the chemical reduction of graphene oxide (GO) through green reductant L-ascorbic acid (L-AA); however, the combination of near ultraviolet (NUV) light to increase the reduction rate has yet to be thoroughly explored. In this study, drop-casted GO films were subjected to chemical reduction through L-AA with various levels of exposure under 405 nm NUV radiation. The structure and uniformity of GO stackings that form the film were characterized through scanning electron microscopy (SEM) and wide-angle x-ray scattering (WAXS). Additionally, WAXS was used to track the removal of oxygen-containing functional groups along with Fourier-transform infrared (FT-IR) spectroscopy and x-ray photoelectron spectroscopy (XPS) as a function of L-AA and NUV light exposure times. XPS results demonstrated that the interaction between L-AA and NUV exposure has a significant effect on the reduction of films. Furthermore, the results that yielded the highest reduction (C-C bond concentration of 60.7%) were the longest L-AA and NUV light exposure times (48 hours and 3 hours, respectively). This report provides a study on the effects of NUV on the green reduction of GO films through L-AA with potential application in solar energy and chemical sensing applications. Graphical abstract
Bulletin of the American Physical Society, 2020
Bulletin of the American Physical Society, 2019
Bulletin of the American Physical Society, 2020
Physical Chemistry Chemical Physics, 2020
Multidisciplinary experimental and theoretical study highlighting the molecular-scale structural ... more Multidisciplinary experimental and theoretical study highlighting the molecular-scale structural and dynamic properties of CO2 capture solvents during a temperature-, time- and CO2-loading-dependent metastable/glassy transition.
ACS central science, Jan 22, 2018
Understanding the origins of lipid membrane bilayer rearrangement in response to external stimuli... more Understanding the origins of lipid membrane bilayer rearrangement in response to external stimuli is an essential component of cell biology and the bottom-up design of liposomes for biomedical applications. The enzymes phospholipase C and D (PLC and PLD) both cleave the phosphorus-oxygen bonds of phosphate esters in phosphatidylcholine (PC) lipids. The atomic position of this hydrolysis reaction has huge implications for the stability of PC-containing self-assembled structures, such as the cell wall and lipid-based vesicle drug delivery vectors. While PLC converts PC to diacylglycerol (DAG), the interaction of PC with PLD produces phosphatidic acid (PA). Here we present a combination of small-angle scattering data and all-atom molecular dynamics simulations, providing insights into the effects of atomic-scale reorganization on the supramolecular assembly of PC membrane bilayers upon enzyme-mediated incorporation of DAG or PA. We observed that PC liposomes completely disintegrate in ...
Research Summary: An increase of the alkyl chain length of the cation of room temperature ionic l... more Research Summary: An increase of the alkyl chain length of the cation of room temperature ionic liquids (RTILs) influences the nanoscale structure and dynamics of RTILs, which in turn affect the behavior of RTILs at solid-liquid interfaces central to energy storage devices. We integrate classical molecular dynamics (CMD) simulation, fluorescence correlation spectroscopy (FCS), time resolved fluorescence anisotropy decay (TRFAD,) small angle X-ray scattering (SAXS) and nuclear magnetic resonance (NMR) to investigate the fundamental properties including structure, dynamics and interfacial behavior of RTIL electrolytes. We found that the elongation of the alkyl chain in the cation gives rise to an enhanced spatial and dynamical heterogeneity, which have been observed in CMD, FCS, TRFAD and SAXS; CMD combined with NMR has revealed the weak temperature dependence of the dynamics of RTILs at a silica surface due to the surface roughness and strong interaction between the ions and silica w...
Soft Matter, 2021
Nanoconfinement of ionic liquids (ILs) influences their physicochemical properties.
Polymer, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Water Process Engineering, 2019
Abstract We report the ZnO nanoparticle-templated formation of nanoporous carbon (NTC) embedded w... more Abstract We report the ZnO nanoparticle-templated formation of nanoporous carbon (NTC) embedded with TiO2 nanoparticles for the adsorption and photodegradation of organic pollutants in water. Small-angle X-ray scattering (SAXS) studies indicate that NTC and NTC-TiO2 exhibit two types of porosities with average pore diameters of 2.8 and 11.5 nm, while Brunauer-Emmet-Teller (BET) surface area analysis revealed the surface area of 302 and 230 m2/g, respectively. These materials exhibit fast adsorption kinetics against methylene blue, ofloxacin, and tetracycline in water. Exposure of NTC-TiO2 to UV-light results in higher contaminant adsorption due to the active photodegradation which prevents the saturation of the nanocomposite.
ABSTRACT Breakthroughs in the performance of energy storage technologies come from efficient comb... more ABSTRACT Breakthroughs in the performance of energy storage technologies come from efficient combinations of novel electrolytes and electrode materials. Knowledge of the structure of these materials under applied electric fields is necessary to better tailor them to our energy needs. Neutron scattering, as a structural probe to investigate the ordering of electrolytes at an interface, or the effects of confinement on an electrolyte in a nanoporous matrix, is well suited since the electrolytes commonly used contain hydrogen and the host matrix can often contain active sites that are difficult to discern without the use of contrast matching via isotopic substitution. We present small angle neutron scattering results, conducted at the EQ-SANS (ORNL) instrument and at the Low-Q Diffractometer (LANL), from in situ electrochemical measurements of a deuterated ionic liquid, and of aqueous electrolytes, in a mesoporous carbon membrane at different applied potentials over time. Recent neutron reflectometry measurements (LR, SNS) complement the observed behavior from SANS. We observe a higher electrolyte density near the electrode material surface, compared to without an applied potential. Furthermore, this high density region persists long after the applied potential is removed.
The Journal of Physical Chemistry C, 2013
Review of Scientific Instruments, 2012
A new high-pressure cell design for use in neutron reflectometry (NR) for pressures up to 50 MPa ... more A new high-pressure cell design for use in neutron reflectometry (NR) for pressures up to 50 MPa and a temperature range of 300-473 K is described. The cell design guides the neutron beam through the working crystal without passing through additional windows or the bulk fluid, which provides for a high neutron transmission, low scattering background, and low beam distortion. The o-ring seal is suitable for a wide range of subcritical and supercritical fluids and ensures high chemical and pressure stability. Wafers with a diameter of 5.08 cm (2 in.) and 5 mm or 10 mm thickness can be used with the cells, depending on the required pressure and momentum transfer range. The fluid volume in the sample cell is very small at about 0.1 ml, which minimizes scattering background and stored energy. The cell design and pressure setup for measurements with supercritical fluids are described. NR data are shown for silicon/silicon oxide and quartz wafers measured against air and subsequently within the high-pressure cell to demonstrate the neutron characteristics of the high-pressure cell. Neutron reflectivity data for supercritical CO(2) in contact with quartz and Si/SiO(2) wafers are also shown.
The Journal of Physical Chemistry Letters, 2012
Molecular dynamics (MD) simulations of 1-alkyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl... more Molecular dynamics (MD) simulations of 1-alkyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([C n MPy][Tf 2 N], n = 3, 4, 6, 8, 10) were conducted using an all-atom model. Radial distribution functions (RDF) were computed and structure functions were generated to compare with new X-ray scattering experimental results, reported herein. The scattering peaks in the structure functions generally shift to lower Q values with increased temperature for all the liquids in this series. However, the first sharp diffraction peak (FSDP) in the longer alkyl chain liquids displays a marked shift to higher Q values with increasing temperature. Alkyl chain-dependent ordering of the polar groups and increased tail aggregation with increasing alkyl chain length were observed in the partial pair correlation functions and the structure functions. The reasons for the observed alkyl chaindependent phenomena and temperature effects were explored.
... Authors: Jacob Urquidi (New Mexico State University). Jose L. Banuelos (New Mexico State Univ... more ... Authors: Jacob Urquidi (New Mexico State University). Jose L. Banuelos (New Mexico State University). ... SANS has been used to characterize the shape, size and polydispersity of these reverse micelle systems which are macroscopically clear but nanoscopically heterogeneous. ...
Aps Meeting Abstracts, Mar 1, 2009
ABSTRACT The ability of proteins to change their conformation in response to changes in their env... more ABSTRACT The ability of proteins to change their conformation in response to changes in their environment has consequences in biological processes like metabolism, chemical regulation in cells, and is believed to play a role in the onset of several neurodegenerative diseases. Factors such as concentration, degree of crowding from other entities, and solvent medium affect how a protein folds. As a protein unfolds, the ratio of nonpolar to polar groups exposed to water changes, affecting a protein's thermodynamic properties. Using small angle x-ray scattering (SAXS), we are currently studying the intermediate protein conformations that arise during the folding/unfolding process as a function of temperature for a series of globular proteins. The temporal stability of these ensembles is also under investigation. Trends in the scattering profiles, along with correlations with protein thermodynamics, may help elucidate shared characteristics between all proteins in their folding behavior.
Molecular dynamics simulations were performed on piperidinium-based ([C4mpip+][Tf2N-]) and pyrrol... more Molecular dynamics simulations were performed on piperidinium-based ([C4mpip+][Tf2N-]) and pyrrolidinium-based ([Cnmpy+]][Tf2N-], n=3, 4, 6, 8, 10) ionic liquids at 1 atm over a wide range of temperatures. The temperature-dependent transport properties of free ionic liquids, including diffusion coefficients and reorientational correlation time were calculated and were found to agree very well with the results measured in NMR and Fluorescence anisotropy experiments. The computed small angle X-ray structure factors of ([Cnmpy+]][Tf2N-] at varying temperatures exhibited a good agreement with the corresponding SAXS experimental results. Spatial heterogeneity of ([Cnmpy+]][Tf2N-] was also investigated. With the alkyl chain length increasing, the diffusion was slower. Additionally, the tail-tail radial distribution function showed that as the alkyl chain length increases, the nanoaggregation of cations becomes more significant. This result was also proved in the SAXS experiments.