Current Research

Waldow Group Research Projects

Our group has a number of research directions broadly focused in the study of macromolecules.  The largest effort has been involved in the compatibilization of polymer blends with added copolymers both in the bulk and as a thin film. Other areas include the study of organic photovoltaic thin films, local segmental dynamics of copolymers in dilute solution, and the application of various synthetic technique to design and build specialty polymers and copolymers.

Novel Homopolymers and Diblock Copolymers for Use as Solid Polymer Electrolytes in Lithium Ion Batteries

This research is focused on improving the storage and utilization of energy in lithium-ion batteries with increased safety. Ring opening metathesis polymerization (ROMP) will be used to synthesize various diblock copolymers and homopolymers with applications in battery and fuel cell membranes as well as potentially in organic electrochemical transistors. The diblock copolymer structures synthesized develop nanometer morphologies potentially allowing these materials to improve performance and safety in lithium ion batteries. The nano-morphology of these materials will be studied as a function of block molecular weight allowing lamellar, cylinder, sphere, and gyroid morphologies to be produced on a sub 100 nanometer length scale. In addition, the influence of the nano-morphology on ionic motion will be investigated. One block in the material will allow for both thermal and structural support while the second block will provide ion mobility. The materials will be characterized using many instruments including NMR, GPC, AFM, dielectric relaxation spectroscopy, and electrochemistry at PLU, and potential analysis using AFM and thermal analysis at the University of Washington, X-ray instrumentation at Argonne National Laboratory, and / or neutron instrumentation from Oak Ridge National Laboratory.

Polymer Thin Films: Polymer Blends and OPVs

My groups had studied local segmental dynamics of polybutadiene and PS/PB copolymers in dilute solution. This research is directed at understanding the cooperativity of local segmental transitions that take place especially in copolymer structures. C-13 spin-lattice (T_¹) relaxation is used to investigate these copolymer dynamics.

Polymer Synthesis

We have developed local expertise primarily in positive pressure living anionic polymerization and Grubbs-based ring opening metathesis polymerization. We have used anionic polymerization to make various homopolymers and di-, tri-, and tetra-block copolymers of butadiene and styrene. We also have been synthesizing many new homopolmer, block copolymer, and random copolymer materials using ROMP techniques with norbornene and oxanorbornene monomers we have synthesized in house.

Copolymer Compatibilization of Polymer Blends

Copolymers have often been used to compatibilize polymer blends through favorable interactions with the blend domains. One monomer of the copolymer will strongly interact with the phase rich in that same monomer and vice versa with the other monomer. We have traditionally studied two model polymer blend using polystyrene and polybutadiene with one model system having a low molecular weight allowing both the homogeneous and phase separated phased to be accessed. The other model system has molecular weights above their respective entanglement molecular weights restricting the accessible phase to only the phase separated region. We use 1) cloud point measurements, wide angle, dynamic, and static light scattering as well as small angle neutron scattering, 2) light microscopy (LM) and atomic force microscopy (AFM), 3) Monte Carlo simulations, and 4) anionic and controlled radical synthetic techniques.

Local Segmental Dynamics of Copolymers in Dilute Solution

My groups had studied local segmental dynamics of polybutadiene and PS/PB copolymers in dilute solution. This research is directed at understanding the cooperativity of local segmental transitions that take place especially in copolymer structures. C-13 spin-lattice (T_¹) relaxation is used to investigate these copolymer dynamics.