A5009930323- Surface Chemistry and Catalysis
- Molecular Junctions and Nanostructures
- Porphyrin and Phthalocyanine Chemistry
- Atmospheric chemistry and aerosols
- Nanocluster Synthesis and Applications
- Combustion and Detonation Processes
- Air Quality and Health Impacts
- Atmospheric Ozone and Climate
- Advanced Combustion Engine Technologies
- Carbon Dioxide Capture Technologies
- Electrochemical Analysis and Applications
- Refrigeration and Air Conditioning Technologies
- Brake Systems and Friction Analysis
- Surface and Thin Film Phenomena
- Force Microscopy Techniques and Applications
- Synthesis and properties of polymers
- Atmospheric aerosols and clouds
- Metal-Organic Frameworks: Synthesis and Applications
- Machine Learning in Materials Science
University of California, Irvine
2023-2025
Tennessee Technological University
2025
Washington State University
2019-2022
Motor vehicles are among the major sources of pollutants and greenhouse gases in urban areas a transition to "zero emission vehicles" is underway worldwide. However, emissions associated with brake tire wear will remain. We show here that previously unrecognized volatile semi-volatile organic compounds, which have similarity biomass burning emitted during braking. These include or, these classified as Hazardous Air Pollutants, well nitrogen-containing organics, nitrogen oxides ammonia. The...
The uptake and desorption of organics on silica surfaces is important in both outdoor indoor environments.
Scanning tunneling microscopy (STM) was used to observe and quantify single-molecule diffusion at the solution/solid interface argon/solid interface. This work investigates influence of temperature, solvent, STM tip on isolated molecular surface through analysis trajectories in sequential images. The Y[C6S-Pc]2 phenyloctane found be thermally activated with almost no motion observed 5 °C, whereas, above 30 °C and/or adsorption/desorption are so rapid that it becomes difficult track single...
This study explores directed noncovalent bonding in the self-assembly of nonplanar aromatic carboxylic acids on gold and graphite surfaces. It is first step developing a new design strategy to create two-dimensional surface metal-organic frameworks (SURFMOFs). The acid molecules used are tetraphenylethene-based typically employed synthesis three-dimensional (3D) MOF crystalline solids. They include tetraphenylethene tetracarboxylic acid, bisphenyl tetrakis-phenyl acid. structures formed from...
Thermal desorption measurements, including thermal mass spectrometry, are often used to determine the volatility and chemical composition of secondary organic aerosol (SOA). Accurately interpreting such measurements requires understanding response SOA heat. Using optical microscopy, we monitored catechol + O₃ during heating at mild temperatures (36-52 °C). Catechol is a type formed in wildfire plumes. Surprisingly, particles appeared boil when heated these temperatures. We identified acetone...
Thermal desorption measurements, including thermal mass spectrometry, are often used to determine the volatility and chemical composition of secondary organic aerosol (SOA). Accurately interpreting such measurements requires an understanding response SOA heat. Using optical microscopy, we monitored catechol + O3 during heating mild temperatures (36–52 °C). Catechol is a type formed in wildfire plumes. Surprisingly, particles appeared boil when heated these temperatures. We identified acetone...
We present a quantitative study comparing the binding of 4-methoxypyridine, MeOPy, ligand to Co(ii)octaethylporphyrin, CoOEP, at phenyloctane/HOPG interface and in toluene solution. Scanning tunneling microscopy (STM) was used porphyrin receptors adsorbed on graphite. Electronic spectroscopy employed for examining this process fluid The surface coordination reaction completely reversible followed simple Langmuir adsorption isotherm. Ligand affinities (or ΔG) processes two different chemical...
Kinetic analysis of surface reactions at the single molecule level is important for understanding influence substrate and solvent on reaction dynamics mechanisms, but it difficult with current methods. Here we present a stochastic kinetic oxygenation cobalt octaethylporphyrin (CoOEP) solution/solid interface by monitoring fluctuations from equilibrium using scanning tunneling microscopy (STM) imaging. Image movies were used to monitor oxygenated deoxygenated state dwell times. The rate...
Uptake coefficients of
Scanning tunneling microscopy (STM) was employed to quantitively investigate in situ binding of 3-phenyl thiophene (PhTh) Co(II)octaethyl porphyrin (CoOEP) supported on highly ordered pyrolytic graphite (HOPG) fluid solution. To our knowledge, this is the first single-molecule level study a complexation reaction between metalloporphyrin and sulfur base at solution/solid interface one few examples coordination with d7 transition metal. Real-time imaging experiments revealed that PhTh binds...
A new approach combines uptake and the temperature programmed desorption measurements to provide a molecular-level view of atmospheric particle growth. Adsorption/desorption on silica particles is discussed in terms gas structural features.
Abstract: Metalloporphyrins have been shown to bind axial ligands in a variety of environments, including the vacuum/solid and solution/solid interfaces. Understanding dynamics such interactions is desideratum for design implementation next generation molecular devices which draw inspiration from biological systems accomplish diverse tasks as sensing, electron transport, catalysis name few. In this article, we review current literature ligand coordination surface-supported porphyrin...
Single molecule level time-dependent binding of O 2 to cobalt(II) octaethylporphyrin [CoOEP] supported on graphite at the solution-solid interface was observed with scanning tunneling microscopy (STM). Using STM movies surface and a stochastic kinetic analysis it possible extract both dissociation rate constants for this reversible equilibrium process. This study first its kind has opened way if reactions single by methodology. These results are transformative based studies because they...