[Lecture] Polymers at synthetic and biological surfaces


Title: Polymers at synthetic and biological surfaces
Speaker: Prof. Harm-Anton Klok, Ecole Polytechnique Fédérale de Lausanne
Venue: Room 324, Building No.2, National Science Park, North Area, Wushan Campus
Time: January 7, Tuesday, 14:30 

Harm-Anton Klok is Full Professor at the Institutes of Materials and Chemical Sciences and Engineering at the Ecole Polytechnique Fédérale de Lausanne (EPFL) (Lausanne, Switzerland). He studied chemical technology at the University of Twente (Enschede, The Netherlands) from 1989 to 1993 and received his Ph.D. in 1997 from the University of Ulm (Germany) after working with Martin Möller. After postdoctoral research with David N. Reinhoudt (University of Twente) and Samuel I. Stupp (University of Illinois at Urbana–Champaign, USA), he joined the Max Planck Institute for Polymer Research (Mainz, Germany) in early 1999 as a project leader in the group of Klaus Müllen. In November 2002, he was appointed to the faculty of EPFL. Since 2012 he is Director of the Institute of Materials (~ Department Head) and also directs the Molecular and Hybrid Materials Characterization Center at EPFL.

In many applications, polymer materials interact with other polymer or non-polymer based materials. In some cases these interactions are desired while in others less so. In this presentation, I will present three examples of recent work from our laboratory, which cover a range of fundamental problems and phenomena at the interface between polymers and synthetic or biological surfaces. 

1) Selective deposition on surfaces: Deposition of polymers or polymer particles in a selective and controlled manner onto textiles, hair or skin is highly relevant for a range of cosmetic applications. We will present a novel strategy that uses short and highly selective peptide motifs to enhance the deposition of polymers and polymer particles onto cotton and hair under conditions that are representative for the use of washing softeners and hair shampoos.

2) Mechanochemistry at polymer interfaces: It has been known for a long time that, for example, mastication, ultrasound or high shear forces can lead to scission of covalent bonds. Using surface-grafted polymers as an example, we will show that swelling-induced chain stretching is an alternative mechanism that can lead to build-up of tension at polymer – substrate interfaces. Although the tension is not sufficient to cause scission of covalent bonds, it can facilitate, for example, hydrolysis reactions that otherwise would not proceed under ambient conditions. We believe these findings also have implications for other coatings and hydrogels.

3) Controlled delivery: Controlled delivery is an important challenge, not only in medicine, but also for example in agriculture. Eukaryotic and prokaryotic cells possess unique properties that could help to address several delivery-related challenges, not just in human medicine, but also beyond, for example in agriculture. To explore living cells for these purposes, strategies need to be developed to decorate these carriers with polymers and polymer particles in a controlled manner. We will show recent work in which we have decorated living cells with polymer nanoparticles and which underlines the opportunities and challenges of integrating living cells and polymers.

Announced by the School of Molecular Science and Engineering