The Experts below are selected from a list of 130011 Experts worldwide ranked by ideXlab platform
Suljo Linic - One of the best experts on this subject based on the ideXlab platform.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:The excitation of metal nanoparticles with light can lead to localized surface plasmon resonances, capable of driving chemical reactions in bound species. Here, the authors elucidate this Mechanism and suggest that future plasmonic catalysts may be able to selectively activate specific chemical bonds.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:Plasmonic metal nanoparticles enhance chemical reactions on their surface when illuminated with light of particular frequencies. It has been shown that these processes are driven by excitation of localized surface plasmon resonance (LSPR). The interaction of LSPR with adsorbate orbitals can lead to the injection of energized charge carriers into the adsorbate, which can result in chemical transformations. The Mechanism of the charge injection process (and role of LSPR) is not well understood. Here we shed light on the specifics of this Mechanism by coupling optical characterization methods, mainly wavelength-dependent Stokes and anti-Stokes SERS, with kinetic analysis of photocatalytic reactions in an Ag nanocube-methylene blue plasmonic system. We propose that localized LSPR-induced electric fields result in a direct charge transfer within the molecule-adsorbate system. These observations provide a foundation for the development of plasmonic catalysts that can selectively activate targeted chemical bonds, since the Mechanism allows for tuning plasmonic nanomaterials in such a way that illumination can selectively enhance desired chemical pathways.
Calvin Boerigter - One of the best experts on this subject based on the ideXlab platform.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:The excitation of metal nanoparticles with light can lead to localized surface plasmon resonances, capable of driving chemical reactions in bound species. Here, the authors elucidate this Mechanism and suggest that future plasmonic catalysts may be able to selectively activate specific chemical bonds.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:Plasmonic metal nanoparticles enhance chemical reactions on their surface when illuminated with light of particular frequencies. It has been shown that these processes are driven by excitation of localized surface plasmon resonance (LSPR). The interaction of LSPR with adsorbate orbitals can lead to the injection of energized charge carriers into the adsorbate, which can result in chemical transformations. The Mechanism of the charge injection process (and role of LSPR) is not well understood. Here we shed light on the specifics of this Mechanism by coupling optical characterization methods, mainly wavelength-dependent Stokes and anti-Stokes SERS, with kinetic analysis of photocatalytic reactions in an Ag nanocube-methylene blue plasmonic system. We propose that localized LSPR-induced electric fields result in a direct charge transfer within the molecule-adsorbate system. These observations provide a foundation for the development of plasmonic catalysts that can selectively activate targeted chemical bonds, since the Mechanism allows for tuning plasmonic nanomaterials in such a way that illumination can selectively enhance desired chemical pathways.
Fleming Martinez - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic analysis and enthalpy entropy compensation for the solubility of indomethacin in aqueous and non aqueous mixtures
2011Co-Authors: Fleming Martinez, Angeles M Pena, Pilar BustamanteAbstract:Abstract The solubility of indomethacin was measured at several temperatures (20–40 °C) at the polarity range provided by aqueous (ethanol–water, solubility parameter δM = 26.51–47.97 MPa1/2) and non-aqueous (ethanol–ethyl acetate δM = 26.51–18.49 MPa1/2) mixtures. The solubility curve displays a single peak in the least polar mixture (δM = 20.91 MPa1/2, 30% ethanol-in ethyl acetate). The thermodynamic functions of solution and mixing were obtained. In ethanol–water, the enthalpy of solution curve against solvent composition passes through a maximum at 50% ethanol. The solubility enhancement is entropy driven at the water-rich region (50–100% water) and enthalpy controlled at the ethanol-rich region (50–100% ethanol). In the non-aqueous mixture, the enthalpy of solution displays a minimum (30% ethanol), and the enthalpy change is the Dominant Mechanism. The aqueous mixture shows a parabolic enthalpy–entropy compensation relationship, and the slope change can be related to a shift of the Dominant Mechanism from enthalpy to entropy. For the non-aqueous mixture, there are not slope changes, indicating that a single Mechanism, enthalpy, controls the solubility enhancement. The results show the usefulness of the enthalpy–entropy compensation analysis to identify changes of the Mechanism of co-solvent action. A solubility model using a minimum number of solubility experiments provides excellent solubility predictions for indomethacin in aqueous and non-aqueous mixtures.
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solution thermodynamics of ketoprofen in ethanol water cosolvent mixtures
2010Co-Authors: Mauricio Gantiva, Alicia Yurquina, Fleming MartinezAbstract:Ketoprofen (KTP) is an anti-inflammatory drug widely used in therapeutics. By using the van’t Hoff and Gibbs equations, the thermodynamic functions Gibbs energy, enthalpy, and entropy of solution and mixing for KTP in ethanol (EtOH) + water cosolvent mixtures were evaluated from solubility data determined at several temperatures. The solubility was greater in pure EtOH and lower in water at all temperatures studied. This behavior shows the cosolvent effect present in this system. By means of enthalpy−entropy compensation analysis, a nonlinear ΔsolnH0 vs ΔsolnG0 plot with negative slope from pure water up to 0.6 in mass fraction of EtOH and positive beyond this EtOH proportion was obtained. Accordingly to this result, it follows that the Dominant Mechanism for solubility of KTP in water-rich mixtures is the entropy, probably due to water-structure loosening around the drug nonpolar moieties by EtOH, whereas over 0.6 in mass fraction of EtOH, the Dominant Mechanism is the enthalpy probably due to the KTP so...
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thermodynamic analysis of the solubility of naproxen in ethanol water cosolvent mixtures
2007Co-Authors: Diana P Pacheco, Fleming MartinezAbstract:By using the van't Hoff and Gibbs equations the thermodynamic functions free energy, enthalpy, and entropy of solution, mixing, and solvation of naproxen (NAP) in ethanol (EtOH) + water (W) cosolvent mixtures, were evaluated from solubility data determined at several temperatures. The solubility was greater in pure ethanol and lower in water at all temperatures studied. This result shows the cosolvent effect present in this system. The solvation of this drug in the mixtures increases as the EtOH proportion is also increased in the mixtures. By means of enthalpy–entropy compensation analysis, nonlinear versus compensation with negative slope from pure water up to 30% EtOH and positive slope from 30% EtOH up to 70% EtOH was obtained. Over 70% EtOH the behavior was more complex. Accordingly to these results it follows that the Dominant Mechanism for solubility of NAP in water-rich mixtures is the entropy, probably due to water-structure loosing by EtOH; whereas, over 30% EtOH the Dominant Mechanism is the en...
Robert Campana - One of the best experts on this subject based on the ideXlab platform.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:The excitation of metal nanoparticles with light can lead to localized surface plasmon resonances, capable of driving chemical reactions in bound species. Here, the authors elucidate this Mechanism and suggest that future plasmonic catalysts may be able to selectively activate specific chemical bonds.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:Plasmonic metal nanoparticles enhance chemical reactions on their surface when illuminated with light of particular frequencies. It has been shown that these processes are driven by excitation of localized surface plasmon resonance (LSPR). The interaction of LSPR with adsorbate orbitals can lead to the injection of energized charge carriers into the adsorbate, which can result in chemical transformations. The Mechanism of the charge injection process (and role of LSPR) is not well understood. Here we shed light on the specifics of this Mechanism by coupling optical characterization methods, mainly wavelength-dependent Stokes and anti-Stokes SERS, with kinetic analysis of photocatalytic reactions in an Ag nanocube-methylene blue plasmonic system. We propose that localized LSPR-induced electric fields result in a direct charge transfer within the molecule-adsorbate system. These observations provide a foundation for the development of plasmonic catalysts that can selectively activate targeted chemical bonds, since the Mechanism allows for tuning plasmonic nanomaterials in such a way that illumination can selectively enhance desired chemical pathways.
Matthew Morabito - One of the best experts on this subject based on the ideXlab platform.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:The excitation of metal nanoparticles with light can lead to localized surface plasmon resonances, capable of driving chemical reactions in bound species. Here, the authors elucidate this Mechanism and suggest that future plasmonic catalysts may be able to selectively activate specific chemical bonds.
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evidence and implications of direct charge excitation as the Dominant Mechanism in plasmon mediated photocatalysis
2016Co-Authors: Calvin Boerigter, Robert Campana, Matthew Morabito, Suljo LinicAbstract:Plasmonic metal nanoparticles enhance chemical reactions on their surface when illuminated with light of particular frequencies. It has been shown that these processes are driven by excitation of localized surface plasmon resonance (LSPR). The interaction of LSPR with adsorbate orbitals can lead to the injection of energized charge carriers into the adsorbate, which can result in chemical transformations. The Mechanism of the charge injection process (and role of LSPR) is not well understood. Here we shed light on the specifics of this Mechanism by coupling optical characterization methods, mainly wavelength-dependent Stokes and anti-Stokes SERS, with kinetic analysis of photocatalytic reactions in an Ag nanocube-methylene blue plasmonic system. We propose that localized LSPR-induced electric fields result in a direct charge transfer within the molecule-adsorbate system. These observations provide a foundation for the development of plasmonic catalysts that can selectively activate targeted chemical bonds, since the Mechanism allows for tuning plasmonic nanomaterials in such a way that illumination can selectively enhance desired chemical pathways.
