The pathways and timescales of vibrational energy flow in nitromethane are investigated in both gas and condensed phases using classical molecular mechanics, with a particular focus on relaxation in liquid water. We monitor the flow of excess energy deposited in vibrational modes of nitromethane into the surrounding solvent. A marked energy flux anisotropy is found when nitromethane is immersed in liquid water, with a preferential flow to those water molecules in contact to the nitro group. The factors that permit such anisotropic energy relaxation are discussed, along with the potential implications on the molecule's non-equilibrium dynamics. In addition, the energy flux analysis allows us to identify the solvent motions responsible for the uptake of solute energy, confirming the crucial role of water librations. Finally, we also show that no anisotropic vibrational energy relaxation occurs when nitromethane is surrounded by argon gas.
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http://dx.doi.org/10.1063/5.0147459 | DOI Listing |
Environ Sci Technol
January 2025
Department of Civil and Environmental Engineering, Clarkson University, Potsdam, New York 13699, United States.
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View Article and Find Full Text PDFJ Am Chem Soc
January 2025
National Center for International Research on Green Optoelectronics, Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
Ice melting, a common yet complex phenomenon, remains incompletely understood. While theoretical studies suggest that preexisting defects in ice generate "off-lattice" water molecules, triggering bulk ice melting, direct experimental evidence of their form has been lacking as the transparent and transient nature of ice poses significant challenges for observation with current techniques. Here, we introduce an ice-melting-induced lyophilization (IMIL) technique that employs graphene-based nanoprobes to replicate and track liquid evolution within melting bulk ice.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
School of Rare Earths, University of Science and Technology of China, Hefei 230026, China.
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View Article and Find Full Text PDFJ Phys Chem B
January 2025
Department of Computational Sciences, School of Basic Sciences, Central University of Punjab, Bathinda 151401, India.
The effect of confinement on the tetrahedral ordering of liquid water plays a vital role in controlling their microscopic structure and dynamics as well as their spectroscopic properties. In this article, we have performed the classical molecular dynamics simulations of four different CTAB/water/chloroform reverse micelles with varied water content to study how the tetrahedral ordering of nanoscale water inside reverse micellar confinement influences the microscopic dynamics and the structural relaxation of water···water hydrogen bonds and its impact on the low-frequency intermolecular vibrational bands. We have noticed from the results obtained from simulated trajectories the lowering trends of tetrahedral ordering of water pools in reverse micellar confinements as we move from bulk to confined and strictly confined environments.
View Article and Find Full Text PDFACS EST Air
January 2025
Environmental Engineering Program, University of Colorado Boulder, 1111 Engineering Drive, Boulder, Colorado 80309-0428, United States.
Quantifying changes in the properties of smoke aerosols under varying conditions is important for understanding the health and environmental impacts of exposure to smoke. Smoke composition, aerosol liquid water content, effective density (ρ), and other properties can change significantly as smoke travels through areas under different ambient conditions and over time. During this study, we measured changes in smoke composition and physical properties due to oxidative aging and exposure to humidity.
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