Molecular Simulation Of Surfactant Self Assembly From Mesoscale To Multi Scale Modeling

Fully atomistic computer simulations of surfactant self-assembly are extremely challenging because of the different length scales and the associated different times scales, implying large system sizes and tediously long simulations. To overcome this, the uninteresting degrees of freedom at the atomistic level can be integrated out leading to a meso-scale model, which can span the required length and time scales with less computational burden. We use such a meso-scale model to study surfactant self-assembly and how alcohols affect this self-assembly behavior in supercritical carbon dioxide. Here the surfactants and alcohols are represented as a chain of beads where each bead represents a set of atoms. This model is implemented into lattice Monte Carlo simulations. We show that short chain alcohols act as cosurfactants by concentrating in the surfactant layer of the aggregates, strongly decreasing micellar size and increasing the number of aggregates. In contrast long chain alcohols act as cosolvents by concentrating more in the solvent and increasing the micellar size. We then focus on systematically constructing a meso-scale model that preserves the important aspects of the atomistic model, while spanning these different length and time scales. The process of constructing this meso-scale model from the corresponding atomistic model is called coarse-graining. We first explore the rigorous coarse-graining technique in which we match the partition function of the atomistic model with that of the meso-scale model. Such a rigorous procedure has the advantage that it leads to the reproduction of all the structural and thermodynamic properties of the atomistic model in the meso-scale model. We develop a procedure to calculate the rigorous 1, 2 ... N-body effective interactions using Widom's particle insertion method. We implement this rigorous procedure for a binary ArD r system, where the degrees of freedom of Ar are integrated out. We observed that the structure at.

Keywords: coarse-graining, cosolvent, supercritical, alcohol, co2, cosurfactant, multi-scale, simulation, modeling, surfactant, self-assembly, effective potential.

We demonstrate that neglecting their contribution leads to qualitative discrepancies in predicted surfactant addition rates and propose a stochastic model for the monomer addition which takes the additional degrees of freedom into account. The model parameters are extracted from molecular dynamics simulations and the surfactant addition rates are determined from Brownian dynamics simulations of this model. The obtained addition and removal rates are then incorporated into the kinetic model of micelle formation and disintegration. It is expected that insights gained in the course of development of the multi-scale model for this relatively simple self-assembly process will aid in the development of models for dynamics of more complex processes in amphiphilic systems such as collision of reverse micelles involved in formation of nanoparticles, rheology of worm-like micellar solutions, and fusion of lipid bilayers.

Discover how the latest computational tools are building our understanding of particle interactions and leading to new applications With this book as their guide, readers will gain a new appreciation of the critical role that particle interactions play in advancing research and developing new applications in the biological sciences, chemical engineering, toxicology, medicine, and manufacturing technology The book explores particles ranging in size from cations to whole cells to tissues and processed materials. A focus on recreating complex, real-world dynamical systems helps readers gain a deeper understanding of cell and tissue mechanics, theoretical aspects of multiscale modeling, and the latest applications in biology and nanotechnology. Following an introductory chapter, Multiscale Modeling of Particle Interactions is divided into two parts: Part I, Applications in Nanotechnology, covers: Multiscale modeling of nanoscale aggregation phenomena: applications in semiconductor materials processing Multiscale modeling of rare events in self-assembled systems Continuum description of atomic sheets Coulombic dragging and mechanical propelling of molecules in nanofluidic systems Molecular dynamics modeling of nanodroplets and nanoparticles Modeling the interactions between compliant microcapsules and patterned surfaces Part II, Applications in Biology, covers: Coarse-grained and multiscale simulations of lipid bilayers Stochastic approach to biochemical kinetics In silico modeling of angiogenesis at multiple scales Large-scale simulation of blood flow in microvessels Molecular to multicellular deformation during adhesion of immune cells under flow Each article was contributed by one or more leading experts and pioneers in the field. All readers, from chemists and biologists to engineers and students, will gain new insights into how the latest tools in computational science can improve our understanding of particle interactions and support the development of novel applications across the broad spectrum of disciplines in biology and nanotechnology.

Multiscale modeling is becoming essential for accurate, rapid simulation in science and engineering. This book presents the results of three decades of research on multiscale modeling in process engineering from principles to application, and its generalization for different fields. This book considers the universality of meso-scale phenomena for the first time, and provides insight into the emerging discipline that unifies them, meso-science, as well as new perspectives for virtual process engineering. Multiscale modeling is applied in areas including: multiphase flow and fluid dynamics chemical, biochemical and process engineering mineral processing and metallurgical engineering energy and resources materials science and engineering Jinghai Li is Vice-President of the Chinese Academy of Sciences (CAS), a professor at the Institute of Process Engineering, CAS, and leader of the EMMS (Energy-minimizing multiscale) Group. Wei Ge, Wei Wang, Ning Yang and Junwu Wang are professors at the EMMS Group, part of the Institute of Process Engineering, CAS. Xinhua Liu, Limin Wang, Xianfeng He and Xiaowei Wang are associate professors at the EMMS Group, part of the Institute of Process Engineering, CAS. Mooson Kwauk is an emeritus director of the Institute of Process Engineering, CAS, and is an advisor to the EMMS Group.

This book stems from the American Chemical Society symposium, Large Scale Molecular Dynamics, Nanoscale, and Mesoscale Modeling and Simulation: Bridging the Gap, that delved into the latest methodologies and applications for largescale, multiscale, and mesoscale modeling and simulation. It presents real-world applications of simulated and synthesized materials, including organic-, inorganic-, bio-, and nanomaterials, and helps readers determine the best method for their simulation. It gets novices up to speed quickly and helps experienced practitioners discover novel approaches and alternatives.

The application fields of colloid and interface chemistry are very wide, covering many aspects such as industrial and agricultural production, daily chemistry, enhanced oil recovery, and so on. The traditional experimental analysis of a colloid and interface chemistry system includes various instrumental analysis methods such as spectroscopy, rheometer, microscopes, etc. In recent decades, molecular simulation has become an important research method in this field. It can investigate at the molecular level and provide mechanisms or insights that are hard or even impossible to obtain from an experiment. Many applications of molecular simulation have been reported in the literature, such as the behavior of surfactant, self-assembly, enhanced oil recovery, adsorption around interface, etc. This reprint has collected ten research articles which relate to the application of molecular dyamics simulation in colloide and interface chemistry.

Dynamics of Surfactant Self-Assemblies explains the dynamics of micellar equilibria, tracking surfactant exchange, and micelle formation/breakdown processes. Highlighting the structural similarities of amphiphilic block copolymers to surfactants, this volume elucidates the dynamics of more complex self-assemblies that surfactants and amphiphilic bl