Projects Related to Sustainability

Antifouling Polymers

Antifouling polymers play important roles in a variety of applications such as biomedical implants, drug delivery, membranes for separation, and coatings used in the marine environment, etc. Recently, zwitterionic polymers have been developed into powerful environmentally friendly marine antifouling materials with many advantages to replace current toxic coatings.

It is widely believed that the excellent antifouling performance of zwitterionic polymers is due to the strong surface hydration, which prevents other molecules from displacing surface bound water to stick to the surface.

We are using SFG to study the relationship between surface hydration and state-of-the-art antifouling zwitterionic polymer coatings. The effects of the distance between the positive and negative charges on the interfacial hydration and the antifouling performance of zwitterionic polymers are under the current investigation. We also aim to understand the impact of charge delocalization on the zwitterionic polymer antifouling activity.

In addition to the zwitterionic polymers, we are studying various amphiphilic polymers, nanostructured coatings, and silicone materials for antifouling and fouling-release purposes.

Oil-Water Separation: Interfacial Corn protein behavior

Effectively separating oil and water leads to sustainable solutions for cleaning and reusing water, reducing, and minimizing waste, protecting the environment, and conserving resources.

We successfully applied SFG to elucidate molecular behavior of corn oil protein at corn oil/water interfaces, demonstrating that the ordered interfacial corn protein prevents corn oil-water separation.

We also found that surfactant molecules could remove/disrupt the interfacial proteins, facilitating oil-water separation.

We are applying SFG to study molecular interactions between corn proteins and various surfactants including nonionic surfactants, anionic surfactants, and extended surfactants, developing improved strategies for oil-water separation.

Interfaces in Battery

Compared to traditional gasoline cars, electric vehicles typically have a smaller carbon footprint. Battery is the key component for an electric vehicle. Electrochemistry at anodes and cathodes plays important roles in determining the performance of batteries. Many details regarding the interfacial electrochemical reactions on electrodes are not known.

SFG is a unique and powerful technique which can probe chemical reactions at buried electrode interfaces in situ at the molecular level.

We are investigating electrode/electrolyte solution interfaces using SFG to understand crucial interfacial interactions which greatly impact battery efficiency, especially Li ion batteries.

Interfaces of Conducting Polymers and in Solar Cells

Extensive research has been performed to study conducting polymers, which have many advantages for a variety of applications such as sustainable and flexible electronics, solar cells, drug delivery vehicles, anti-corrosion coatings, and biosensing devices.

We are applying SFG to examine conducting interfacial polymer behavior at interfaces in solar cells. It was found that conducting polymer orientation at interfaces greatly influences solar cell conversion efficiency.

We are studying interfacial interactions between conducting polymers and various 2-D materials such as graphene and MoS2.

We aim to follow the ultrafast dynamics of interfacial conducting polymer materials to understand interfacial electron transfer kinetics.

Degradation Mechanisms of Polymers

Polymers are widely used in many important applications such as packaging, construction, microelectronics, automobiles, healthcare products, and so on. Plastic waste accumulating in the environment has created a growing concern. Plastics usually take several years to break down in landfills, and those entering the natural environment pose threats to life and the food chain.

To understand the fates of plastic debris and devise strategies to mitigate plastic accumulation, it is necessary to understand polymer degradation mechanisms.

We are applying a combination of analytical techniques including infrared spectroscopy, Raman microscopy, X-ray diffraction, and nano-indentation to evaluate the physical and chemical changes of polymer materials upon solar exposure, bacteria/fungi incubation, and lake deployment to provide insights of the polymer degradation process.