NMR Group
Dr. von Meerwall

Self-diffusion of polymer melts and blends:
Prof. von Meerwall and his students currently are studying the self-diffusion of viscous polymer liquids (alkanes and polyethylene; polybutadiene), pure and in binary blends. This work is done in collaboration with Prof. Mattice and recently also with Prof. Wang (both Polymer Science) and some of their students. The point is to understand exactly how the temperature, molecular weight, and concentration affect the diffusion coefficients, which are measured with the nuclear magnetic resonance (NMR) method. The results are compared in detail with theoretical models and with numerical simulations of self-diffusion in these systems. Recent extensions of this work concentrate on cyclic polymers and on binary blends of highly entangled linear polymers.
Recycling of various industrial rubbers:
Prof. von Meerwall and his group are also interested in the recycling of various industrial rubbers (styrene-butadiene; natural rubber; silicone rubber) to help give them a second life. He collaborates with Prof. Isayev (Polymer Engineering) and some of his students to investigate at the molecular level how powerful ultrasound causes rubbery materials to disintegrate. NMR relaxation and diffusion measurements reveal the molecular motions of various components of the polymer network after it is broken up. The idea is to prepare for industrial implementation of the ultrasound method and to maximize its effectiveness. The project is now evolving to include industrially important rubbers containing solid filler particles.

Development and characterization of biocompatible polymer materials:
Prof. von Meerwall and members of his group are collaborating with Prof. Kennedy (Polymer Science) and with Profs. Cheung and Lopina (Chemical Engineering) and their students to develop and characterize biocompatible polymer membranes and bicontinuous composites . These are suitable for implants into the body, and will either enclose bioactive substances subject to attack by the immune system, e. g., in the treatment of diabetes, or else directly deliver drugs at carefully controlled rates. NMR diffusion measurements indicate the permeability of various membranes or composites to molecules of widely different sizes and shapes.

In addition, Prof. von Meerwall's group collaborates widely with polymer scientists whose studies call for measurements of molecular motions and diffusion in rubbery polymers, networks, and colloids. The laboratory frequently hosts graduate students and colleagues from other departments at Akron, and from other universities and laboratories.