Material Type  

 학위논문

 

0015492982

Date and Time of Latest Transaction  

20200217181916

ISBN  

9781392449516

DDC  

620

Author  

Hou, Jie.

Title/Author  

Microscopic Diffusion/Relaxation Dynamics of Surface Adsorbates

Publish Info  

[Sl] : Rensselaer Polytechnic Institute, 2019

Publish Info  

Ann Arbor : ProQuest Dissertations & Theses, 2019

Material Info  

94 p

General Note  

Source: Dissertations Abstracts International, Volume: 81-06, Section: B.

General Note  

Advisor: Liu, Li.

학위논문주기  

Thesis (Ph.D.)--Rensselaer Polytechnic Institute, 2019.

Restrictions on Access Note  

This item must not be sold to any third party vendors.

Restrictions on Access Note  

This item must not be added to any third party search indexes.

Abstracts/Etc  

요약In confinement, adsorbate, the matter which is confined, shows very different properties from those of the bulk, due to its reduced size, dimensionality of the confinement and interaction from the substrate, where the adsorbate is confined. Confinement has drawn extensive interest from the researchers since it is ubiquitous in the nature and predominantly determines the unique behaviors of various systems ranging from protein dynamics, chemical reaction to crude oil extraction.In recent decades, several experimental techniques have been developed and adopted to the probe the substrate-adsorbate systems at different size scale and time scale. So far the systems investigated in the experimental techniques are tremendously versatile and few universal traits about the substrate-adsorbate systems could be extracted out of them, not to mention that few experiments are aimed at discovering such features, including the dependence of the dynamics of the adsorbate/substrate on some basic quantities, such as temperature, surface coverage of the adsorbate and relative strength of the substrate-adsorbate interaction. Qualitatively, one empirical knowledge of the dynamics in the adsorbate is that, the adsorbate generally becomes more and more dynamic as the distance to the substrate increases, and there exists a minimal threshold of the amount of the adsorbate, only above which the adsorbate will show some features of the bulk, including the cage effect and the super-Arrhenius behavior of the self diffusion coefficient to the temperature. However, even such understanding is rare and precious when it comes to predicting the properties in the confined system. The lack of the knowledge of the basic properties across different substrate-adsorbate systems always results in incorrect assumptions about the possible dynamic behaviors in the adsorbate-substrate systems, which are made when the experiments are still under preparation, and dooms the experiments consequently. Apart from the experimental methods that are adopted to probe the substrate-adsorbate systems, the simulation method of the classical molecular dynamics (MD) could also explore those systems in the virtual way. As a matter of fact, the classical MD method, is able to not only provide the experimental results with the corresponding simulated results as a comparison, but also help to develop a better understanding of the universal features that govern the properties in the substrate-adsorbate systems, including the dependence on the temperature, surface coverage and so on, since it is indeed an ideal approach to extract the universal traits behind versatile confined systems, thanks to its abilities 1) to build and explore more generic systems in the virtual way, 2) to avoid the problems about the resolution and temperature range that may trouble the experimental methods and 3) to analyze the behavior of every individual particle in the system it explores.So far only in a small fraction of the experimental studies on the substrate-adsorbate systems, the classic MD work have been carried out and served as the computational comparison to the experimental results, and very limited studies attempt to discover the universal trait that governs the dynamics of the adsorbate/substrate throughout different systems. Hence, in this dissertation, we will adopt the classic MD method to take a thorough investigation into the properties of the generic substrate-adsorbate systems at different coverages and temperatures, and try to discover any universal trait behind. Generally, this dissertation addresses the aforementioned research gap in the following ways: 1) It builds some quite generic substrate-adsorbate systems and thoroughly investigates their thermodynamic and kinetic behaviors at various surface coverages and temperatures. Those results draw the overview picture of the properties of the surface adsorbate system. 2) It proposes a novel approach to characterize the lateral diffusivity of the adsorbate and reveals a straightforward relation between the average lateral diffusivity of the entire adsorbate and the average lateral diffusivities in different layers (the latters are defined in our approach), and further helps to analyze the translational behavior of the adsorbate particles in different layers and to successfully explain the non-monotonic behavior of the lateral diffusivity in the adsorbate to the surface coverage. 3) It discovers the surface coverage-dependent phase transition phenomenon in the adsorbate and fully explains it via investigating the lateral structures of the adsorbate particles in the adsorbate layers. By accomplishing these, our research workimproves the fundamental understanding of the substrate-adsorbate systems and supports the relevant research area with stronger predictive powers.

Subject Added Entry-Topical Term  

Nuclear engineering

Subject Added Entry-Topical Term  

Engineering

Added Entry-Corporate Name  

Rensselaer Polytechnic Institute Nuclear Engineering and Science

Host Item Entry  

Dissertations Abstracts International. 81-06B.

Host Item Entry  

Dissertation Abstract International

Electronic Location and Access  

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소장사항  

202002 2020

Control Number  

joongbu:569742