Polymer Coatings and Polymer Brushes

Coatings for Circularity: Recovering molecules with and from smart coatings

 

Background

Sustainable and circular processes in chemistry are critical to achieve our climate action goals and move towards a circular economy. However, circularity on a molecular level is practically difficult and economically unfeasible due to the high energy and solvent use in chemical separation processes. In our group, we research novel materials to recover valuable molecules from process streams that otherwise could have ended up as waste. In collaboration with industry, we investigate responsive coatings that can capture and release these valuable molecules using electric field as a trigger.

 

Research directions

Our group participates in two large projects working on these industrial challenges: ReCoVR (Recovery and Circularity of Valuable Resources) and ELECTRIFIED. Within these projects, we investigate how we can control the capture and release of two primary target groups: proteins and flavor molecules. Currently, our research focuses on polyelectrolyte brushes, self-assembled monolayers, and polymer gels. These coatings all contain charged moieties and thus they change their structure in response to applied electric fields. This change in structure leads to capture or release of target molecules.

 

Switching mechanism 

Our coatings consist of large molecules with neutral segments at the grafted end of the molecule and charged segments at its free end. Without an applied electric field, the charged segments in our molecules attract oppositely charged target molecules, capturing the target molecule. When we apply an electric field, the charged segments bend back toward the surface, leading to a release of the target molecule. In our lab, we synthesize these coatings with polyelectrolyte brushes and self-assembled monolayers and we investigate how we can improve the capture and release our target molecules.

Circularity for brushes

Generally, polymer brushes are long-lasting coatings, which generate additional plastic waste. Therefore, it is important to consider additional design methodologies to produce circular brushes. Such brushes will degrade after a certain period of time and its depolymerization products may be used again to synthesize new brushes. In our group, we aim to understand and tackle the challenges to translate the knowledge on degradable polymers in bulk towards degradable polymer brushes.