Eugenia Kumacheva's Polymers, Interfaces, and Materials Science Group

Polymer Science

We are interested in fundamental studies of polymers and in polymer materials science. Below is a brief description of the areas of research in the group.

1. Nanofibrillar gels 1.

Many biological polymers form filaments or fibrils that associate to form nanofibrillar hydrogels.  These hydrogels are very different than their molecular counterparts. We are interested in the behavior and properties of nanofibrillar hydrogels under confinement in narrow capillaries. This question is of immense importance for biological and biomedical systems. For example, the structure and properties fibrin hydrogels determine the properties of blood clots that cause myocardial infarctions, strokes and pulmonary embolism. On the other hand, embolization of blood capillaries with polymer hydrogel particles can be used to reduce blood supply to tumor sites. This area of research is cross-listed with our research in Microfluidics.

Representative publications  

· Li et al.  The Motion of a Microgel in an Axisymmetric Constriction with a Tapered Entrance. Soft Matt. 9, 10391-10403 (2013).

· Fiddes et al. A Circular Cross-Section PDMS Microfluidics System for Replication of Cardiovascular Flow Conditions. Biomaterials 13, 3459-3464 (2010).

· Fiddes et al. Augmenting Microgel Flow via Receptor-Ligand Binding in the Constrained Geometries of Microchannels. Lab Chip 9, 286-290 (2008).

2. Nanofibrillar gels 2. 

We are interested in the development of hydrogels that mimic the biophysical and biochemical properties of extracellular matrix. In particular, cellulose nanocrystals have the size and shape resembling collagen strands. We explore the applications of cellulose nanocrystals and cellulose nanofibrils modified with polymers and peptides to form nanofibrillar hydrogels for cell culture.

Representative publications

· Chau et al. Ion-Mediated Gelation of Aqueous Suspensions of Cellulose Nanocrystals. Biomacromolecules 16, 2455−2462 (2015).

·  Chau et al. Supramolecular Nanofibrillar Polymer Hydrogels. Adv. Polym. Scie. 268, pp. 167-208 (2015).

3. Polymer behavior on highly curved surfaces   

This new project aims at the exploration of the structure of polymer molecules attached to highly curved surfaces such as small nanoparticles. The structure of surface-tethered polymer layers can dramatcially change under the action of external stimuli. This effect has two important implications. First, it can be used for nanoparticle patterning. Second, it may be used for the design of particles for applications in ambient evnironments with varying pH, ionic strength or temperature. This area of research is cross-listed with our research in the Nanoscience area.

4. Smart polymer materials

We conceptualize, design, synthesize and fabricate polymer and polymer-inorganic composite materials with advanced properties and interesting applications. One group of projects embraces self-shaping polymers that acquire a specific, well-defined shape under a particular external stimulus. These materials can be used in soft robotics and sensing. The second group of projects targets materials derived from natural resources, e.g., cellulose nanocrystals and nanofibers. We particularly interested in optical and mechanical properteis of such materials that can be used for security applications, sensors, lasers and films with unique mechanical properties.

Representative publications

·Thérien-Aubin et al. Co-assembly of Nanorods and Nanospheres in Suspensions and in Stratified Films. Angew. Chem. Int. Ed. 54, 5618-5622 (2015).

· Thérien-Aubin et al. Structure and Properties of Composite Films Formed by Cellulose Nanocrystals and Charged Latex Nanoparticles. Nanoscale 7, 6612-6618 (2015).

· Querejeta-Fernández, A.; Chauve, G.; Methot, M.; Bouchard, J.; Kumacheva, E. Chiral Plasmonic Films Formed by Gold Nanorods and Cellulose Nanocrystals. J. Am. Chem. Soc. 136, 4788-4793 (2014).