(693c) Conformations of Linear and Bottlebrush Polymeric Surfactants at the Interface

Polymer surfactants, with their hydrophilic and hydrophobic segments, are pivotal macromolecules widely utilized in diverse chemical and biological systems such as oil recovery, painting, and nanoemulsion formulation. These macromolecules boast complex structures, encompassing linear, star, comb-like, and bottlebrush polymers, offering immense potential for various applications. However, a comprehensive understanding of their fundamental structure-property relationships remains limited. In this study, we employ coarse-grained molecular dynamics simulations to gain molecular-level insights into the conformations of linear and bottlebrush polymers at both oil/water and air/water interfaces. The hydrophilic and hydrophobic segments of both linear and bottlebrush polymers consist of oligomers of ethylene oxide and styrene, respectively. Specifically, we investigate two representative structures of bottlebrush polymers: the Janus and diblock configurations. In the Janus structure, the hydrophilic and hydrophobic segments alternate along the polymer chain, whereas they form distinct blocks in the diblock polymer. Our findings reveal distinct conformations of linear and bottlebrush polymeric surfactants at water/oil interfaces. In addition, we will delve into their assembly at the interface and assess the interfacial tension of water/surfactant/oil systems. These microscopic insights into the conformations of linear and bottlebrush polymeric surfactants offer valuable perspectives on their macroscopic properties, providing essential guidance for the design of tailored polymeric surfactants suited to specific applications.