Dr. Kuljeet Kaur
Polymer laboratory, Institute of Materials, School of Engineering, (LP-IMX-STI) EPFL


Understanding interfacial properties of surface-grafted polymer assemblies


A polymer brush is a dense assembly of polymer chains covalently tethered to a surface. When swollen in a good solvent, they acquire a stretched chain conformation away from the substrate, which imparts them with unique properties. The extended chain conformation of swollen polymer brush makes them useful for a number of surface applications like sensors, adhesives, lubricants, and anti-fouling surfaces. However, solvent exposure can also result in instabilities in the polymer brush films leading to detachment or delamination at the brush-substrate interface.1,2 While the effects of polymer molecular weight and composition, grafting density, and nature of the solvent on the swelling of polymer brushes are well studied, the role of the brush-substrate interface is less known, partly due to limited chemistries available for interfacial modification.

In this talk, I will present a design of a library of probes that can be inserted at the polymer brush interface and allow for systematic modulation of interfacial properties. I will address two main questions, i) can we modulate swelling by tuning the interfacial chemistry, and ii) what are the forces that act at the interface upon swelling of the brush. Furthermore, I will discuss the scope of applications of these probes in both hydrophobic and hydrophilic polymer brush systems, and how they can help us better understand the interfacial phenomenon in polymer brushes.
1 N. C. Ataman and H. A. Klok, Macromolecules, 2016, 49, 9035–9047.
2 J. Wang and H. A. Klok, Angew. Chemie - Int. Ed., 2019, 58, 9989–9993.


Kuljeet Kaur is currently an NCCR Bioinspired WINS postdoctoral fellow at Polymer Laboratory (LP), Institute of Materials (IMX) at EPFL, where she works with surface-grafted polymer thin films. She obtained her BSc (Hons) and MSc (Hons.) degrees in chemistry from G.N.D. University, India. She received her PhD in chemistry from Virginia Tech, USA. Her research interests are centered around properties and applications of peptide and polymer based materials.