Application and characterization of polymer coatings for droplet microfluidics and corrosion protection

This dissertation is a compilation of four diverse and multi-disciplinary projects involving collaborations with engineering, chemistry, and anthropology. Chapter 1-4 comprise the work completed on droplet-based microfluidic devices where the effect of surface chemistry, topography and liquid viscosity on droplet actuation in digital microfluidics is explored. Chapters 5-7 involve research on the corrosion protection of iron with polyaniline, the fabrication of biomimetic lotus leaf surfaces, and a unique gold nanoparticle synthesis reaction.; Chapter one introduces droplet based microfluidics and the concepts behind microfluidic devices and droplet movement (actuation). These are concepts fundamental to droplet based microfluidics and are pertinent to chapters 2-4. The goal of chapters 2-3 was to explore a variety of coatings that could replace Teflon AF as the hydrophobic coating on droplet based microfluidic devices. Chapter 2 describes investigations of alternate fluoropolymer coatings and chapter 3 describes the effects of a rough topography on droplet based microfluidics. Chapter 4 is an extension of work done by my collaborator, a doctoral student at UCLA in Biomedical Engineering, Debalina Chatterjee, who modeled the forces on the droplet in our microfluidic devices. The work presented here explores the effect of viscosity and surface chemistry in droplet actuation.; Chapter 5 summarizes the research accomplished through the MCTP internship program with Dr. David Scott of Cotsen Institute of Archaeology and the Departments of Art History and Archaeology at UCLA with collaboration from Dr. Richard Kaner of the Department of Chemistry and Biochemistry at UCLA. In this project, the relative effectiveness in corrosion protection of conventional and nanofiberous polyaniline on iron was investigated. My involvement was with the initial design and set-up of the project and a collaborator, Robyn Hodgkins, will evaluate the samples quarterly during the year of aging.; Chapter 6 describes the experimental design and preliminary results of forming biomimetic lotus leaf structures from covalently bound polymer beads.; Chapter 7 summarizes the extensive work on closo-borate reduced gold nanoparticles which began as a side project to my collaborator Fusayo Saeki. The study encompasses both nanoparticle formation under a variety of conditions, and explores the oxidation products formed from the closo-dodecahydrododecaborate.