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

Nanoscience

1. Developing new concepts for nanoparticle self-assembly                                           

Our group is interested in new strategies for the assembly of nanoparticles in structures with a high degree of order and symmetry, and exploring their collective properties. Our approach builds on the analogy between molecules undergoing a chemical reaction and nanoparticles which, when cleverly designed, behave as "colloidal molecules' to form structures with high level of complexity. This work includes the synthesis of nanoparticles with different dimensions, shapes and compositions, design and synthesis of ligands (in most cases, polymers), the self-assembly experiments, and the characterization of the properties of individual nanoparticles and their ensembles. This work is conducted in collaboration with Prof. Michael Rubinstein (University of North Carolina).

Representative publications

·         Klinkova et al.  Structural and Optical Properties of Self-Assembled Chains of Plasmonic Nanocubes. Nano Lett. 14, 6314-6321 (2014).

·         Liu et al.   Copolymerization of Metal Nanoparticles: A Route to Colloidal Plasmonic Copolymers.  Angew. Chem. Int. Ed. 53, 2648-2653 (2014).

·         Klinkova et al. Colloidal Analogues of Molecular Chain Stoppers. Proc. Nat. Acad. Sci. 110, 18775-18779 (2013).

·         Liu et al.  In Situ Plasmonic Counter for Polymerization of Chains of Gold Nanorods in Solution. ACS Nano 7, 5901-5910 (2013).

·         Lee et al.  Probing Dynamic Generation of Hot-Spots in Self-Assembled Chains of Gold Nanorods by SERS.  J. Am. Chem. Soc.133, 7563-7570 (2011).

·         Liu et al. Step-Growth Polymerization of Inorganic Nanoparticles. Science 329, 197-200 (2010).

·         Nie, et al. 'Supramolecular' Assembly of Gold Nanorods End-Terminated with Polymer 'Pom-Poms': Effect of 'Pom-Pom' Structure on the Association Modes. J. Am. Chem. Soc. 130, 3683-3689 (2008).

·         Nie, Z et al. Self-assembly of Metal-Polymer Analogues of Amphiphilic Triblock Copolymers. Nature Mater. 6, 609-614 (2007).

2. Nanoparticle patterning                                             

We are interested in structures formed by polymer ligands on highly curved surfaces of nanoparticles. This new exploratory project should address the question of patterning the surface of nanoparticles with supramolecular polymer structures.  Such nanoparticles can exhibit properties similar to molecules or atoms but on the length scale that is two orders of magnitude larger. On the fundamental side, this work would provide understanding of how the structure of polymer ligands of nanoparticle surface can change under applied external stimulus (temperature, change in pH or ionic strength).

3. Nanoparticles derived from natural resources

We are developing materials derived from cellulose nocrystals and nanofibers. In one project, we are interested in hydrogels that can be used in tissue engineering applications. In another project, we syntehsize and fabricate materials with interesting optical properties, based on the self-assembly of cellulose nanocrystals in cholesteric structures.  We also work with composite materials formed by cellulose nanocrystals and polymer, metal, carbon and metal oxide nanoparticles.

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).

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

·         Querejeta-Fernández et al. Chiral Plasmonic Films Formed by Gold Nanorods and Cellulose Nanocrystals. J. Am. Chem. Soc. 136, 4788-4793 (2014).