Stimuli responsive polymers, including gels, brushes, and self-assembled structures, can swell or change shape in response to changes in temperature, pressure, and solvent or solute concentration. Understanding such behavior has the potential to enable design and control of unique chemical processes involving lubricants, viscosity modifiers, and surface coatings. To predict polymer swelling, conformational changes of polymer brushes, swelling of gels, and partitioning of components, a model must incorporate molecular architecture and intermolecular interactions across a range of length scales from solvent to polymers while remaining computationally tractable. Molecular density functional theory has shown great promise in modeling response of micelles, grafted copolymers, dendrimers, and bottlebrush polymers to associating solvents and solutes.
In this work, we present the response of branched polymers (dendrimers and bottlebrush polymers) in good and poor solvents using classical density functional theory. We consider copolymer brushes and mixed brushes and distributions of association sites on the polymer brushes. Good agreement is found in comparison with molecular simulation results. The results also agree well with scaling theories for brush height.
