Materials Behavior

Research Methodology and Mathematical Models

Mihai Ciocoiu

• Publisher: Apple Academic Press
• Year: 2018
• eBook ISBN: 9780429845338
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

The development of advanced materials has become extremely important in the last decade, being widely used in academic and industrial research. This book examines the potential of advanced materials as well as nanotechnology to improve fiber science from fibril to fabric mode, to create better materials and products for a variety of aspects.

The book presents research advances in materials behavior using fractal analysis, mathematical modeling and simulation, and other methods. Examined are electrical, mechanical, optical, and magnetic properties; size; morphology; and chemical behavior of such materials as aerogels, polymer films, nanocomposite materials, natural composites, catalysis, and more with a view to their application in the medical, engineering, and textile fields.

With chapters written by eminent scientists, the book offers valuable information for academics, researchers, and engineering professionals. Contributions range from new methods to novel applications of existing methods to help readers gain understanding of the material and/or structural behavior of new and advanced systems.

CHAPTER 1

UNDERSTANDING MODELING AND SIMULATION OF AEROGELS BEHAVIOR: FROM THEORY TO APPLICATION

M. DILAMIAN

University of Guilan, Rasht, Iran

CONTENTS

Abstract

1.1 Theory

1.2 Applications

1.3 Conclusion

Keywords

References

ABSTRACT

A deeper understanding of phenomena on the microscopic scale may lead to completely new fields of application. As a tool for microscopic analysis, molecular simulation methods such as the molecular dynamics (MD), Monte Carlo (MC) methods have currently been playing an extremely important role in numerous fields, ranging from pure science and engineering to the medical, pharmaceutical, and agricultural sciences. MC methods exhibit a powerful ability to analyze thermodynamic equilibrium, but are unsuitable for investigating dynamic phenomena. MD methods are useful for thermodynamic equilibrium but are more advantageous for investigating the dynamic properties of a system in a nonequilibrium situation. The importance of these methods is expected to increase significantly with the advance of science and technology. The purpose of this study is to consider the most suitable method for modeling and characterization of aerogels. Initially, giving an introduction to the Molecular Simulations and its methods help us to have a clear vision of simulating a molecular structure and to understand and predict properties of the systems even at extreme conditions. Considerably, molecular modeling is concerned with the description of the atomic and molecular interactions that govern microscopic and macroscopic behaviors of physical systems. The connection between the macroscopic world and the microscopic world provided by the theory of statistical mechanics, which is a basic of molecular simulations. There are numerous studies mentioned the structure and properties of aerogels and xerogels via experiments and computer simulations. Computational methods can be used to address a number of the outstanding questions concerning aerogel structure, preparation, and properties. In a computational model, the material structure is known exactly and completely, and so structure/property relationships can be determined and understood directly. Techniques applied in the case of aerogels include both “mimetic” simulations, in which the experimental preparation of an aerogel is imitated using dynamical simulations, and reconstructions, in which available experimental data is used to generate a statistically representative structure. In this section, different simulation methods for modeling the porous structure of silica aerogels and evaluating its structure and properties have been mentioned. Many works in the area of simulation have been done on silica aerogels to better understand these materials. Results from different studies show that choosing a suitable potential leads to a more accurate aerogel model in the other words if the interatomic potential does not accurately describe the interatomic interactions, the simulation results will not be representative of the actual material.

1.1 THEORY

1.1.1 INTRODUCTION

The idea of using molecular dynamics (MD) for understanding physical phenomena goes back centuries. Computer simulations are hopefully used to understand the properties of assemblies of molecules in terms of their structure and the microscopic interactions between them. This serves as a complement to conventional experiments, enabling us to learn something new, something that cannot be found out in other ways. The main concept of molecular simulations for a given intermolecular “exactly” predict the thermodynamic (pressure, heat capacity, heat of adsorption, structure) and transport (diffusion coefficient, viscosity) properties of the system. In some cases, experiment is impossible (inside of stars weather forecast), too dangerous (flight simulation explosion simulation), expensive (high pressure simulation wind channel simulation), and blind (Some properties cannot be observed on very short time-scales and very small space-scales). The two main families of simulation technique are MD and Monte Carlo (MC); additionally, there is a whole range of hybrid techniques, which combine features from both. In this lecture we shall concentrate on MD. The obvious advantage of MD over MC is that it gives a route to dynamical properties of the system: transport coefficients, time-dependent responses to perturbations, rheological properties and spectra. Computer simulations act as a bridge Fig. 1.1) between microscopic length and time scales and the macroscopic world of the laboratory: we provide a guess at the interactions between molecules, and obtain ‘exact’ predictions of bulk properties. The predictions are ‘exact’ in the sense that they can be made as accurate as we like, subject to the limitations imposed by our computer budget. At the same time, the hidden detail behind bulk measurements can be revealed. An example is the link between the diffusion coeffic...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• List of Contributors
• List of Abbreviations
• List of Symbols
• Preface
• 1. Understanding Modeling and Simulation of Aerogels Behavior: From Theory to Application
• 2. Biodegradable Polymer Films on Low Density Polyethylene and Chitosan Basis: A Research Note
• 3. A Detailed Review on Behavior of Ethylene-Vinyl Acetate Copolymer Nanocomposite Materials
• 4. The Influence of the Electron Density Distribution in the Molecules of (N)-Aza-Tetrabenzoporphyrins on the Photocatalytic Properties of Their Films
• 5. On Fractal Analysis and Polymeric Cluster Medium Model
• 6. Polymers as Natural Composites: An Engineering Insight
• 7. A Cluster Model of Polymers Amorphous: An Engineering Insight
• 8. A Note On Modification of Epoxy Resins by Polyisocyanates
• 9. Trends in Application of Hyperbranched Polymers (HBPs) in the Textile Industry
• 10. A Comprehensive Review on Characterization and Modeling of Nonwoven Structures
• Index