(6jx) Designing the Structure and Function of Soft, Complex Materials with Computational Modeling

Soft, complex materials like colloidal dispersions and polymer solutions are widespread in many fields of science and engineering, including biotechnology, consumer products, and advanced materials. Because of their weak internal interactions, soft materials must be carefully engineered to obtain the desired properties under the conditions in which they are processed and deployed; these conditions are often far from equilibrium. A key outstanding technological challenge is to relate the controllable microscopic characteristics of a soft material and its processing conditions to its emergent macroscopic properties (e.g., self-assembled structure, rheology). This relationship can then be inverted to design materials tailored for a specific application. Computer simulations are powerful tools for tackling this problem; they provide detailed microscopic information that can be used to develop predictive models, and they can be used within an inverse-design framework to rapidly determine optimal candidate materials that can be tested in collaborative experiments.

During my graduate research (with Prof. Thanos Panagiotopoulous, Princeton University), I developed multiscale models to study the coupled relationship between structure and dynamics in mixtures of colloids and polymers driven out of equilibrium. I demonstrated how the microscopic interactions in flowing colloidal suspensions affect the solute spatial distribution and long-time dynamics in confinement, which are relevant to enhanced oil recovery, lab-on-a-chip devices, and membrane separations. I also showed how drying controls self-assembly in thin films, including colloidal crystallization and demixing, with applications in the fabrication of functional coatings and polymer nanocomposites. As a postdoctoral fellow (with Prof. Tom Truskett, University of Texas at Austin), I am applying my foundation in computational modeling to new research areas with a focus on design—namely, reconfigurable nanoparticle gels with targeted optical and rheological properties and porous polymer membranes for water treatment—in close collaboration with experimental research groups.

Building on these prior experiences, my future research program will initially be focused in three principal areas:

1. Designing multilayer coatings by controlled evaporation-induced assembly. There are currently no theoretical models to quantitatively predict the internal structure of mixtures in drying thin films. Such models can be exploited to discover and design the interactions needed to efficiently deposit functional, multilayer coatings with a single-step process.
2. Manipulating nanoscale soft materials with flow. Nanofluidic and microfluidic devices are promising technologies for the continuous separations needed to purify water or to collect rare cell markers in the blood for diseases like HIV and cancer, but most prior design efforts for these devices have been guided primarily by intuition. Mesoscale coarse-grained simulations are a powerful tool to optimize the separations of soft particles using tunable parameters like the device geometry and novel engineered surfaces.
3. Robust, multiscale inverse design of self-assembling materials. Colloidal particles arranged in specific lattices with long-ranged order are good candidates for materials with tunable optical activity, and self-assembly is a promising high-throughput strategy for fabricating them. However, it is a long-standing challenge to efficiently find the appropriate chemistries and conditions that will give the interactions that promote self-assembly into a target structure and not its competitors. Multiscale simulations coupled to a robust inverse-design approach can rapidly find these conditions subject to physical constraints of the experiments.

The aim of all three research projects is to make predictions for optimal designs that can be tested experimentally and translated to realizable technologies.

Teaching Interests:

I believe teaching and mentorship should be integrated into all interactions with students, including in coursework, in research, and with non-traditional learners through community outreach.

I promote an active learning environment that engages students in their coursework with applied examples taken from everyday life and the chemical engineering practice. I use small-group discussions and scaffolded problem-solving to enhance traditional lecture methods, and I solicit anonymous feedback throughout a course to adapt and differentiate its content. As a teaching assistant, I have delivered lectures, created assessments, and run interactive learning sessions for both a graduate-level thermodynamics course (15-30 students) and an undergraduate-level material balance course (50-180 students). In my office hours and lessons, I strove to create a safe and inclusive space where all students were comfortable and able to learn. In future, I have particular interest in teaching thermodynamics and statistical mechanics, transport, and fluid mechanics courses, but I am comfortable teaching all core courses in the chemical engineering curriculum. I additionally hope to develop project-based elective courses in molecular simulation techniques and sustainable scientific software development that can be tailored to both the undergraduate and graduate levels.

In my research group, I will foster a mutually supportive, mentorship-focused, inclusive environment that promotes participation by researchers at all levels of training and experience, especially from historically underrepresented groups in engineering and the computational sciences. My experience so far has strongly evidenced that the best research is done through collaboration of diverse viewpoints. I have had rewarding experiences mentoring undergraduate students through domestic and international programs, leading to multiple peer-reviewed publications. Based on this and the pivotal impact undergraduate research has had in my own career, I will actively involve undergraduate students in my own research group through semester-projects and summer research programs. The development of open-source scientific software, which underlies my research, can act as a gateway for these students that will also build a valuable foundation in a high-demand skill. Mentorship also extends beyond the university; I have engaged in community outreach activities geared towards elementary-school-aged children (e.g., hands-on simple experiments at the library, science fair), and I will continue to develop and participate in these activities in future.