Predicting the properties of polymeric materials via multiscale molecular modeling

Y.G. Yingling
North Carolina State University,
United States

Keywords: molecular modeling, polymers, composites, polyelectrolytes

Summary:

Computer simulations can yield a wealth of data on interfacial dynamics, structures, and a variety of physical properties and have proven to be essential in elucidating complex processes in organic solvents, polymers, and variety of soft materials. Most promising and rigorous methods for simulating complex processes in various materials are based on integration of Newton’s equation of motion, such as molecular dynamics (MD) and dissipative particle dynamics (DPD) simulations. I will illustrate our recent progress on the following two representative efforts: • Role of plasticizers and antioxidants on polymer properties. Plasticizers and antioxidants are additives to polymers that improve materials mechanical properties, stability and durability. In order to develop a new generation of efficient plasticizers and antioxidants a fundamental understanding is needed on what chemical structures and interactions are important in their functional characteristics. We have develop a multiscale MD approach that provided atomic and molecular level understanding of the role of antioxidants exudation and mechanical properties. • Predicting salt responsive morphology of polyelectrolytes micelles and gels. Modeling a responsive material presents a challenge with a large number of unknown variable parameters, such as chemical reactions kinetic or conformational changes as a function of environment, that is hard to measure directly. We have recently developed a method which is parameterized based on a single set of parameters, which allows for large-scale DPD simulations of self-assembling polyelectrolytes materials and their morphological response to the changes in salt concentration. I will illustrate our recent progress in prediction of responsive morphologies of polyelectrolyte micelles and gels. Our methodology permits us to construct a morphological diagram of polyelectrolyte-block copolymers and evaluate the size of aggregates obtained along with their responsive morphological transitions and scaling relations.