Grand challenges in quantum-classical modeling of molecule-surface interactions

2013 ◽  
Vol 34 (14) ◽  
pp. 1177-1188 ◽  
Author(s):  
Claudia R. Herbers ◽  
Chunli Li ◽  
Nico F. A. van der Vegt
Keyword(s):  
Surface Interactions ◽  
Grand Challenges ◽  
Molecule Surface

Three-Dimensional Single Particle Tracking and Its Applications in Confined Environments

2020 ◽  
Vol 13 (1) ◽  
pp. 381-403
Author(s):  
Yaning Zhong ◽  
Gufeng Wang
Keyword(s):  
Mass Transport ◽  
Particle Tracking ◽  
Single Particle ◽  
Three Dimensional ◽  
Surface Interactions ◽  
Single Particle Tracking ◽  
Confined Space ◽  
Design And Optimization ◽  
Chemical Recognition ◽  
Molecule Surface

Single particle tracking (SPT) has proven to be a powerful technique in studying molecular dynamics in complicated systems. We review its recent development, including three-dimensional (3D) SPT and its applications in probing nanostructures and molecule-surface interactions that are important to analytical chemical processes. Several frequently used 3D SPT techniques are introduced. Especially of interest are those based on point spread function engineering, which are simple in instrumentation and can be easily adapted and used in analytical labs. Corresponding data analysis methods are briefly discussed. We present several important case studies, with a focus on probing mass transport and molecule-surface interactions in confined environments. The presented studies demonstrate the great potential of 3D SPT for understanding fundamental phenomena in confined space, which will enable us to predict basic principles involved in chemical recognition, separation, and analysis, and to optimize mass transport and responses by structural design and optimization.

Modeling of Silicon Nanodots Nucleation and Growth Deposited by LPCVD on SiO2 : From Molecule/surface Interactions to Reactor Scale Simulations

2006 ◽  
Vol 959 ◽  
Author(s):  
Ilyes Zahi ◽  
Hugues Vergnes ◽  
Brigitte Caussat ◽  
Alain Esteve ◽  
Mehdi Djafari Rouhani ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deposition Time ◽  
Chemical Vapor ◽  
Surface Interactions ◽  
Nucleation And Growth ◽  
High Dilution ◽  
First Results ◽  
Pressure Chemical ◽  
Molecule Surface

ABSTRACTWe present first results combining models at continuum and atomistic (DFT) levels to improve understanding of key mechanisms involved in silicon nanodots (NDs) synthesis on SiO2 by Low Pressure Chemical Vapor Deposition (LPCVD) from silane SiH4. In particular, by simulating an industrial LPCVD reactor using the CFD code Fluent, we find that the deposition time could be increased and then the reproducibility and uniformity of NDs deposition could be improved when highly diluting silane in a carrier gas. A consequence of this high dilution seems to be that the contribution to deposition of unsaturated species such as silylene SiH2 highly increases. This result is important since our first DFT calculations have shown that silicon chemisorption on silanol Si-OH or siloxane Si-O-Si bonds present on SiO2 substrates could only proceed from silylene (and probably from other unsaturated species). The silane saturated molecule could only contribute to NDs growth, i.e. silicon chemisorption on already deposited silicon bonds. Increasing silylene contribution to deposition in highly diluting silane could then also exalt silicon nucleation on SiO2 substrates and then increase NDs density.

scholarly journals Interfacial Acidity on Oxide Surfaces: A Scaling Paradigm and the Role of the Hydrogen Bond

2020 ◽  
Author(s):  
Robert Chapleski ◽  
Azhad U. Chowdhury ◽  
Kyle Mason ◽  
Robert Sacci ◽  
Benjamin Doughty ◽  
...  
Keyword(s):  
Density Functional ◽  
Critical Role ◽  
Surface Interactions ◽  
Van Der Waals Interactions ◽  
Chemical Transformations ◽  
Acid Base ◽  
Functional Theory ◽  
Fundamental Understanding ◽  
Molecule Surface

<p><a></a>A fundamental understanding of acidity at an interface, as mediated by structure and molecule-surface interactions, is essential to elucidate the mechanisms of a range of chemical transformations. While the strength­­­­ of an acid in the gas and solution phases is conceptually well understood, how acid-base chemistry works at an interface is notoriously more complicated. Using density functional theory and nonlinear vibrational spectroscopy, we have developed a method to determine the interfacial Brønsted-Lowry acidity of aliphatic alcohols adsorbed on the {100} surface of the model perovskite, strontium titanate. Here we show that, while shorter and less branched alkanols are less acidic as a gas and more acidic in solution, shorter alcohols are less acidic whereas less substituted alkanols are more acidic at the gas-surface interface. Hydrogen bonding plays a critical role in defining acidity, whereas structure-acidity relationships are dominated by van der Waals interactions between the alcohol and the surface.</p><p><a></a></p><p> </p>

Interfacial Acidity on Oxide Surfaces: A Scaling Paradigm and the Role of the Hydrogen Bond

2020 ◽  
Author(s):  
Robert Chapleski ◽  
Azhad U. Chowdhury ◽  
Kyle Mason ◽  
Robert Sacci ◽  
Benjamin Doughty ◽  
...  
Keyword(s):  
Density Functional ◽  
Critical Role ◽  
Surface Interactions ◽  
Van Der Waals Interactions ◽  
Chemical Transformations ◽  
Acid Base ◽  
Functional Theory ◽  
Fundamental Understanding ◽  
Molecule Surface

<p><a></a>A fundamental understanding of acidity at an interface, as mediated by structure and molecule-surface interactions, is essential to elucidate the mechanisms of a range of chemical transformations. While the strength­­­­ of an acid in the gas and solution phases is conceptually well understood, how acid-base chemistry works at an interface is notoriously more complicated. Using density functional theory and nonlinear vibrational spectroscopy, we have developed a method to determine the interfacial Brønsted-Lowry acidity of aliphatic alcohols adsorbed on the {100} surface of the model perovskite, strontium titanate. Here we show that, while shorter and less branched alkanols are less acidic as a gas and more acidic in solution, shorter alcohols are less acidic whereas less substituted alkanols are more acidic at the gas-surface interface. Hydrogen bonding plays a critical role in defining acidity, whereas structure-acidity relationships are dominated by van der Waals interactions between the alcohol and the surface.</p><p><a></a></p><p> </p>

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