When a drop of volatile liquid containing particles or solutes evaporates on a surface, it leaves behind those particles/solutes in patterns on the surface. The pattern left depends on the evaporation rate, inter-particle interactions, and Marangoni recirculation. In this project, I explore how the wettability and texture of the substrate influence patterning for an aqueous drop of water containing dissolved salts. In addition to exploring substrate interactions, I also investigate how different properties of salts can lead to previously unexplored phenomena.
PHASE CHANGE, INTERFACES, MATERIALS, WATER CHEMISTRY
Crystallization is enhanced at interfaces due to heterogeneous nucleation. Thus, engineered interfaces can be used to increase crystallization kinetics or to selectively control for specific polymorphs. Properties that can be altered include substrate chemistry, surface energy, texture, and porosity. In this project, I apply these techniques to selectively precipitate useful chemistries from waste streams. Another aspect of this project is using the same principles to create surface that eliminate crystal fouling in water treatment and/or desalination.
Interfacial engineering for control of crystallization
MATERIALS, INTERFACES, FLUID PHYSICS
Collaborative project led by Dr. Luis Zeaat the University of Colorado. Biofilms form when bacteria or fungi colonize a surface by creating a rigid extracellular matrix that enables survival of the colony. Biofilms pose a risk to human health, as they enable contagious bacteria to remain viable outside of a host and create opportunities for new infections when people come into contact with an infected surface. The Space Biofilms project aims to characterize biofilm formation onboard the International Space Station in a controlled fashion, assessing changes in mass, thickness, and morphology due to the microgravity environment. As part of this collaboration, I design and fabricate extreme anti-fouling liquid impregnated and superhydrophobic surfaces that serve as a control to prevent biofilm formation.
Amyloid fibrils are disordered protein structures that self-assembly after an initially folded protein becomes destabilized and reforms into into a long, fibrillar structures. These fibrils are associated with both Parkinson's' and Alzheimers' syndromes. In this project, we explored how a shearing flow can lead to destabilization of protein and formation of fibrils. Although the effect of the shear is too small to cause unfolding, a shearing flow in tandem with adsorption on an interface can create a force large enough to break intermolecular bonds and induce fibrillization. This project was conducted at RPI under Dr. Amir Hirsa as part of my master's thesis.