Jennifer Laaser

Physical Chemistry / Polymer Physics / Polymeric Materials

Polymers are all around us. From our clothing and our building materials to our medications and our foods, polymers - and particularly responsive polymers whose properties change with stimuli like heat, light, and pH -  are a versatile platform for many applications.

In the Laaser Lab, we are interested in developing a detailed understanding of how the molecular-scale chemistry of polymers connects to their macroscopic properties.

Our work is currently focused in two areas:

First, we are very interested in understanding ionic interactions between charged polymer chains.  In this area, one of the things we are exploring is a class of materials called complex coacervates, in which oppositely charged polymers come together in solution to form a hydrated, polymer-rich material with interesting viscoelastic properties.  We use controlled polymer syntheses to systematically vary the chemical compositions of the constituent polymers, and then use a variety of materials characterization techniques to understand how chemical properties like the charge density and hydrophobicity of the polymers affect the coacervates' properties.

In our work on charged polymers, we are also investigating a type of charged polymer system in which polymerization of ionic monomers can "lock" non-equilibrium ion distributions in place over long periods of time. These materials have potential applications in flexible electronic devices, and we are interested in understanding both how the chemical structure of the monomers and polymers affects the timescales on which ions can rearrange, and how chemical we might be able to use chemical triggers to release the ions from the chains on command.

Our second area of focus is on polymer networks.  In this area, one question we are particularly interested in is how forces are transmitted from the macroscopic scale to individual molecules when a material is deformed.  To investigate this problem, we synthesize and characterize polymers containing units called mechanophores that act as molecular-scale reporters of the force on the polymer chains.  By investigating how the activation of these mechanophores depends on the structure of the polymer network, we hope to understand both how networks respond to force, and how rational network design might be used to drive efficient force-triggered chemistry.

Students in our group gain broad exposure to a wide range of methods in polymer chemistry and polymer physics, including small-molecule organic synthesis, controlled radical polymerization, mechanical testing, microscopy, and even computational modelling.  Above all, we try to let the science guide us, and add new techniques to our toolbox as necessary to pursue the scientific questions we're interested in!