BPI Seminar by Dr. Markus Biesalski

Paper-Water Interactions: Understanding & Controlling Wetting, Transport & Mechanical Properties

LOCATION: KAIS #2020 on the 2nd Floor of Fred Kaiser Building at 2332 Main Mall, Vancouver, BC V6T 1Z4

Agenda

• 12:00 PM Intro by Dr. Mark Martinez
• 12:05 PM Presentation by Dr. Markus Biesalski, Chair of Macromolecular Chemistry
  & Paper Chemistry, Department of Chemistry, Technical University of Darmstadt, Germany
• 12:45 PM Q&A

*Sandwiches and coffee will be provided from 11:45 AM. 

Abstract

To control properties of paper in respect to tailor paper-water interactions, several different routes of physical and chemical modification have been used to date and are well-known in technology. An important route is based on chemical modification and makes use of the hydroxyl groups in ligno-cellulosic pulp, for example through the formation of ethers or esters. However, many of the substances used in technology to modify paper are not environmentally friendly. Examples include wet strength agents based on epichlorohydrin or formaldehyde resins. They also make it rather difficult to recycle the paper, a problem well known for wet-strengthened paper. Here a novel approach to paper modification is introduced using C,H insertion reactions. The paper is modified with polymers carrying reactive groups that can be activated by light or heat to form cross-links with any CH-groups in close vicinity. The latter changes significantly the interaction of the pulp fibers with water and leads to a strong rise in the paper wet strength.

In a second part of my talk, I will focus on understanding of fluid imbibition in paper sheets. Experimental analysis of spontaneous dynamic wetting processes is an ongoing challenge. As no time independent equilibrium is established, already small pinning effects lead to experimental uncertainties. The situation becomes even more complicated if the observed system changes its geometry during wetting process, e.g. by water absorption and swelling, as is the case with paper-based materials. To address this problem, a device is built to oppose the capillary force that develops during the wetting and swelling process in paper sheets with a matching centrifugal force. Using such hyper- gravity conditions quasi-static conditions are accessible during paper imbibition which allows e.g. for a simple material analysis such as pore size determination in contact with a swelling solvent.

About the Speaker

Dr. Markus Biesalski studied Chemistry at the University of Mainz, Germany, and received his Ph.D. in Macromolecular Chemistry in 1999 at the Max Planck Institute for Polymer Research. From 2000-2002 he was a postdoctoral fellow at the University of California, Santa Barbara, USA. In 2002 he joined the Faculty of Technology at the University of Freiburg as an Assistant Professor. In 2008 he accepted a call for a professorship at the Technical University of Darmstadt, where he has been since then heading the Chair of Macromolecular Chemistry and Paper Chemistry. The scientific core expertise of his group progresses from polymers at interfaces, the understanding of dynamic processes of fluid imibition of porous materials to the development of functional papers for construction applications, functional paper coatings and the use of renewable raw materials for the design of environmentally sustainable materials. More details can be found at:www.chemie.tu-darmstadt.de/map

Registration