From Nearly Monodispersed toward Truly Monosized Nanocrystals: Chemical Potential Well during Growth of Nanocrystals

2009 ◽  
Vol 9 (10) ◽  
pp. 4235-4238 ◽  
Author(s):  
Hsueh Shih Chen ◽  
Ramachandran Vasant Kumar
Keyword(s):  
Chemical Potential ◽  
Potential Well

Local chemical potential, local hardness, and dual descriptors in temperature dependent chemical reactivity theory

2017 ◽  
Vol 19 (21) ◽  
pp. 13687-13695 ◽  
Author(s):  
Marco Franco-Pérez ◽  
Paul W. Ayers ◽  
José L. Gázquez ◽  
Alberto Vela
Keyword(s):  
Chemical Potential ◽  
Chemical Reactivity ◽  
Potential Well ◽  
Temperature Dependent ◽  
Local Hardness ◽  
Chemical Reactivity Theory ◽  
Definition Of

From the definition of a local chemical potential, well-behaved expressions for the local hardness and the dual descriptors are derived.

scholarly journals Effect of Chemical Potential and Atomic-Scale Vibration of Nucleant Surface on Liquid Layering and Heterogeneous Nucleation

2021 ◽  
Author(s):  
Sida Ma ◽  
Zihui Dong ◽  
Nanfu Zong ◽  
Tao Jing ◽  
Hongbiao Dong
Keyword(s):  
Heterogeneous Nucleation ◽  
Chemical Potential ◽  
Atomic Scale ◽  
Potential Well ◽  
Vibration Strength ◽  
Heterogenous Nucleation ◽  
Well Depth ◽  
Liquid Layering

AbstractThis study reveals the key role of chemical potential and atomic-scale vibration of the nucleant surface in dictating pre-nucleation liquid-layering and heterogenous nucleation. The effect of potential-well depth Dw and vibration strength $$\overline{\beta }_{{{\text{std}}}}$$ β ¯ std of the nucleant surface on the layering and nucleation was examined. We found that nucleants with larger Dw and smaller $$\overline{\beta }_{{{\text{std}}}}$$ β ¯ std induce more ordered pre-nucleation layers to enhance nucleation, and proposed that Dw and $$\overline{\beta }_{{{\text{std}}}}$$ β ¯ std shall be considered when searching for effective nucleants.

Chemical potential and dimensions of chain molecules in athermal environments

1996 ◽  
Vol 89 (6) ◽  
pp. 1733-1754 ◽  
Author(s):  
FERNANDO ESCOBEDO ◽  
JUAN DE PABLO
Keyword(s):  
Chemical Potential ◽  
Chain Molecules

GIANT RESONANCES IN A POTENTIAL WELL : A SEMICLASSICAL DESCRIPTION

1987 ◽  
Vol 48 (C2) ◽  
pp. C2-19-C2-26
Author(s):  
X. VIÑAS ◽  
A. GUIRAO
Keyword(s):  
Potential Well ◽  
Giant Resonances

Growth Kinetics of Quantum Size ZnO Particles

1998 ◽  
Vol 536 ◽  
Author(s):  
E. M. Wong ◽  
J. E. Bonevich ◽  
P. C. Searson
Keyword(s):  
Growth Kinetics ◽  
Ostwald Ripening ◽  
Chemical Potential ◽  
Colloidal Suspensions ◽  
Green Emission ◽  
Blue Shift ◽  
Constant Current ◽  
Mass Model ◽  
Zno Particles ◽  
Kinetics Of

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.

Scalable Approach to High Coverages on Oxides via Iterative Training of a Machine-Learning Algorithm

2019 ◽  
Author(s):  
Andrew Medford ◽  
Shengchun Yang ◽  
Fuzhu Liu
Keyword(s):  
Machine Learning ◽  
Chemical Potential ◽  
Learning Algorithm ◽  
Absolute Error ◽  
Low Energy ◽  
Training Data ◽  
High Coverage ◽  
Metal Compounds ◽  
Adsorption Energies ◽  
The Stability

Understanding the interaction of multiple types of adsorbate molecules on solid surfaces is crucial to establishing the stability of catalysts under various chemical environments. Computational studies on the high coverage and mixed coverages of reaction intermediates are still challenging, especially for transition-metal compounds. In this work, we present a framework to predict differential adsorption energies and identify low-energy structures under high- and mixed-adsorbate coverages on oxide materials. The approach uses Gaussian process machine-learning models with quantified uncertainty in conjunction with an iterative training algorithm to actively identify the training set. The framework is demonstrated for the mixed adsorption of CH<sub>x</sub>, NH<sub>x</sub> and OH<sub>x</sub> species on the oxygen vacancy and pristine rutile TiO<sub>2</sub>(110) surface sites. The results indicate that the proposed algorithm is highly efficient at identifying the most valuable training data, and is able to predict differential adsorption energies with a mean absolute error of ~0.3 eV based on <25% of the total DFT data. The algorithm is also used to identify 76% of the low-energy structures based on <30% of the total DFT data, enabling construction of surface phase diagrams that account for high and mixed coverage as a function of the chemical potential of C, H, O, and N. Furthermore, the computational scaling indicates the algorithm scales nearly linearly (N<sup>1.12</sup>) as the number of adsorbates increases. This framework can be directly extended to metals, metal oxides, and other materials, providing a practical route toward the investigation of the behavior of catalysts under high-coverage conditions.

Intramolecular Proton Transfer in the Isomerization of Hydroxyacetone: A Detailed Characterization Based on Reaction Force Analysis and the Bond Fragility Spectrum

2020 ◽  
Author(s):  
Wallace Derricotte ◽  
Huiet Joseph
Keyword(s):  
Chemical Potential ◽  
Reaction Force ◽  
Intramolecular Proton Transfer ◽  
Intermediate Energy ◽  
Force Analysis ◽  
Activation Energy Barrier ◽  
Detailed Characterization ◽  
Proton Transfers ◽  
Reaction Force Constant

The mechanism of isomerization of hydroxyacetone to 2-hydroxypropanal is studied within the framework of reaction force analysis at the M06-2X/6-311++G(d,p) level of theory. Three unique pathways are considered: (i) a step-wise mechanism that proceeds through formation of the Z-isomer of their shared enediol intermediate, (ii) a step-wise mechanism that forms the E-isomer of the enediol, and (iii) a concerted pathway that bypasses the enediol intermediate. Energy calculations show that the concerted pathway has the lowest activation energy barrier at 45.7 kcal mol<sup>-1</sup>. The reaction force, chemical potential, and reaction electronic flux are calculated for each reaction to characterize electronic changes throughout the mechanism. The reaction force constant is calculated in order to investigate the synchronous/asynchronous nature of the concerted intramolecular proton transfers involved. Additional characterization of synchronicity is provided by calculating the bond fragility spectrum for each mechanism.

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