Understanding the solution behavior of complex soft materials is crucial for designing and optimizing formulations that are relevant in everyday consumer products, including processed foods, detergents, hair care products, and various industrial applications such as lubricants, pesticides, and coatings. These formulations are highly multi-component and involve a wide range of charged molecules, such as polyelectrolytes, surfactants, and colloids, often in the presence of salt and other non-ionic (macro)molecules. While experimental investigations provide valuable insights, they are often limited in their ability to directly observe molecular-level interactions and navigate the vast design space, encompassing numerous parameters such as composition, specific chemical species, macromolecule architecture, molecular weight, temperature, pH, and more.
In this work, we present a multi-scale simulation approach that overcomes the challenges in soft material design by parameterizing mesoscopic field theories based on information obtained from small-scale atomistic simulations. We employ the relative entropy minimization framework to derive chemically-sensitive coarse-grained interaction parameters from all-atom simulations. Subsequently, through an exact transformation, we convert the coarse-grained particle-based model into a more efficient field-theoretic representation, allowing for exploring equilibrium properties and solution phase behavior. This integrated approach preserves the chemical specificity in complex mixtures of interest, enabling de novo studies of solution phase behavior in the field theory without relying on experimental data. Through the exploration of various multi-component formulations, we demonstrate the predictive capability of this simulation workflow in exploring the thermodynamics and complex structures arising in such formulations. This not only contributes to a fundamental understanding of the underlying mechanisms governing solution behavior in complex formulations but also provides invaluable insights for the rational design and optimization of soft matter formulations, contributing to advancements in various industries and sustainable chemical product development.