The innovation engine for new materials

Vedika Shenoy

Vedika Shenoy


Chemical Engineering


University of California, Santa Barbara


Saeed Najafi

Faculty Sponsor(s): 

Megan Valentine

Faculty Sponsor's Department(s): 

Mechanical Engineering

Project Title: 

Investigation of the phase behavior of ABC miktoarm star polymers: binodal vs spinodal decomposition

Project Description: 

Multivalent polymers such as dendrimers and miktoarm stars play a key role in industrial application and medical therapies. One important biologically relevant example is the drug delivery process in which the chemically active agents encaged by polymers after releasing target a specific domain within the cellular environment. The mechanism that leads to the emergence of polymer droplets that can potentially encage drug molecules — called coacervation — is not well understood. Coacervates represent a new class of complex materials that are promising drug delivery vehicles, due to their ability to accommodate a large number of molecules. Establishing a phase diagram that determines the binodal and spinodal boundaries of phase coexistence is critical to understanding the conditions under which coacervates can emerge and function in the desired applications. Here, by employing Complex Langevin Field-Theoretic Simulations (CL-FTS), we delineate the liquid-liquid phase separation boundaries of generic ABC miktoarm stars, which consist of two negatively and positively charged arms and a neutral arm. We vary the length and relative hydrophobicity of the neutral arm to construct phase diagrams to examine the effects of these parameters on phase boundaries. Additionally, we determine the phase region encompassed between the binodal and spinodal phase boundaries. Determination of both of these boundaries is important due to the differences in morphology and kinetics of the two mechanisms of phase separation. Binodal decomposition forms droplets that grow and eventually condensate into a bulk dense phase, while spinodal decomposition rapidly produces unstable clustered phases throughout the entire system. Preliminary CL-FTS results demonstrate that both the binodal and spinodal phase boundaries are diminished in comparison to a phase region of diblock polyampholytes (miktoarm with the neutral arm removed). Understanding the phase behavior of miktoarm polymers is a crucial step in designing the next generation of synthetic polymers for use in biotechnological applications.