Date: Wednesday, January 31
Time: 12pm
Location: EN 3076
Speaker: Audra DeStefano, Chemical Engineering Department and Department of Chemistry
Title of Talk: Surface engineering of polymeric membranes via low temperature atomic layer deposition
Interfaces combining polydopamine (PDA) and nanoparticles have been widely utilized for fabricating hybrid colloidal particles, thin films and membranes for applications spanning biosensing, drug delivery, heavy metal detection, antifouling membranes and lithium ion batteries. However, fundamental understanding of the interaction between PDA and nanoparticles is still limited, especially the impact of PDA on nanoparticle nucleation and growth. In this work, PDA is used to generate functional bonding sites for depositing titanium dioxide (TiO2) via atomic layer deposition (ALD) onto a nanoporous polymer substrate for a range of ALD cycles (<100). Resulting hybrid membranes are systematically characterized using water contact angle, scanning electron microscopy, atomic force microscopy, nitrogen adsorption and desorption, transmission electron microscopy, and x-ray photoelectron spectroscopy (XPS). Our results showed an intriguing nonlinear relationship between the number of ALD cycles and changes in surface properties. Together with XPS study, those changes in surface properties were exploited to probe the nanoparticle nucleation and growth process on complex PDA coated nanoporous polymer substrates. Molecular level understanding of inorganic and polymer material interfaces will shed light on fine-tuning nanoparticle-modified polymeric membrane materials.