(10i) Interfacial Properties and Field-Driven Assembly of Colloidal Nano/Micro Particles 

Our ability to control interparticle potentials underlies many applications of colloids (e.g., paints, coatings, mineral recovery, personal care and food products). Control of interparticle potentials is essential to achieve colloidal stability, to impart directionality on the interactions, or to exploit the emerging properties of colloids through self- and directed-assembly. In this poster, I will explore how the interfacial arrangement of surfactant molecules determines the interaction potential of colloidal carbon nanotubes, their dispersion and separation processes. A combination of small-angle neutron scattering and analytical ultracentrifugation provides key quantitative information on the binding number, hydration (solvation) and conformation of surfactant molecules at the aqueous interface of carbon nanotubes. Further control of the interparticle potential can be achieved by imposing external electric fields on particle ensembles. I will show how the superposition of electric fields on particles with asymmetric surfaces results not only in assembly, but also in unprecedented electrokinetic behavior. Janus particles under direct current electric fields, for example, respond by levitating and forming clusters at high concentrations. Understanding the intricacies of the interactions and electrokinetics of anisotropic colloids is an important step towards achieving dense assemblies that can result in colloidal crystals. Colloidal crystals are of interest for applications such as structural colors, sensing, and camouflage.

Teaching Interests:

My teaching interest lies in the fundamental engineering courses at the undergraduate level. Therefore, although I can certainly teach most of the traditional subjects in the ChE curriculum, my background will best fit to teach classes at the undergraduate level such as Thermodynamics and Transport Phenomena. I am also interested in teaching and further developing a course on the physical chemistry of colloids that can be taken by advance undergraduate and graduate students. After serving as a teaching assistant for a year and mentoring four undergraduate students in research projects, I realized that teaching is an intellectual challenge that can potentially be a gratifying experience for my students and myself. To fulfill that potential, I am willing to tap into the collected knowledge of my colleagues, the findings of cognitive psychology and STEM education research.