Functional materials: Exploiting dynamic self-assembly at interfaces

 

Abstract

 

     We are interested in the development of controlled polymer architectures, hybrid nanoparticle-soft matter assemblies and the integration of dynamic supramolecular systems at interfaces. Current research projects in the group include the application of macrocyclic host-guest chemistry using cucurbit[n]urils in the development of novel microcapsules, supramolecular hydrogels, drug-delivery systems based on dynamic hydrogels, adhesion between a variety of surfaces, the conservation and restoration of important historical artefacts1a through the exploitation of supramolecular polymer chemistry and sensing and catalysis using self-assembled nanophotonic systems.

     Modification of solution viscosity using multivalent polymers has been accomplished through dynamic cross-linking in water using CB[8]. These hydrogels, with extremely high water content (up to 99.75% water by weight), have also been prepared by utilising renewable cellulose derivatives. Their rapid formation1b and shear-induced flow properties make these materials perfectly suited for use as injectable hydrogels for delivery of therapeutics.

      Polymer-inorganic composite materials can be readily prepared based on the CB[8] coupling of multivalent gold nanoparticles (AuNPs) to functional copolymers. When these systems are attached onto gold surfaces intricate control is achieved over the site-selective immobilisation of colloids and peptides. This has great scope for the development of optical materials, chemical sensors2 and biological separations. Additionally, we have developed an innovative new technique for manufacturing 'smart' microcapsules in large quantities using continuous flow in a single step from tiny droplets of water.3a The major advantage of this manufacturing platform over current methods is that a variety of cargos can be efficiently loaded during the microcapsule formation at room temperature, and the dynamic supramolecular interactions provide control over the porosity of the capsules and the timed release of their contents using stimuli.3b Our CB[n] based host-guest systems exhibit dynamic self assembly and are capable of responding to stimuli (photochemical, chemical, and thermal) allowing for external control and function to be built into the materials.

 

References

1. (a) Walsh, Z.; Janecek, E.R.; Hodgkinson, J.T.; Sedlmair, J.; Koutsioubas, A.; Spring, D.R.; Welch, M.; Hirschmugl, C.J.; Toprakcioglu, C.; Nitschke, J.R.; Jones, M.; Scherman, O.A. Proc. Nat. Acad. Sci. USA, 2014, 111, 17743–17748. (b) Appel, E.A.; Forster, R.A.; Koutsioubas, A.; Toprakcioglu, C.; Scherman, O.A. Angew. Chem. Int. Ed., 2014, 53, 10038–10043.

2. (a) Kasera, S.; Herrmann, L.O.; del Barrio, J.; Baumberg, J.J.; Scherman, O.A. Sci. Rep., 2014, 4, 6785. (b) Herrmann, L.O.; Valev, V.K.; Tserkezis, C.; Barnard, J.S.; Kasera, S.; Scherman, O.A.; Aizpurua, J.; Baumberg, J.J. Nat. Commun., 2014, 5, 4568.

3. (a) Zheng, Y.; Yu, Z.; Parker, R.M.; Wu, Y.; Abell, C.; Scherman, O.A. Nat. Commun. 2014, 5, 5772. (b) Zhang, J.; Coulston, R.J.; Jones, S.T.; Geng, J.; Scherman, O.A.*; Abell, C.* Science, 2012, 335, 690–694.

 

 

Short biography

 

Oren Scherman graduated from Cornell University in Ithaca, New York, with a BA in Chemistry in 1999. He then moved to Pasadena, California, where he completed a PhD in 2004 in the area of olefin metathesis and controlled polymerisation, under the supervision of Professor Robert H. Grubbs at the California Institute of Technology (Caltech). After finishing his PhD, Oren moved to the Netherlands to work on supramolecular polymers with Professors E.W. Meijer and Rint P. Sijbesma at the Eindhoven University of Technology. In 2006, he moved to the University of Cambridge to take up an academic appointment as a University Lecturer and Next Generation Fellow in the Melville Laboratory for Polymer Synthesis in the Department of Chemistry. In 2012, he was promoted to Reader in Supramolecular and Polymer Chemistry and in March 2013, he was appointed as the Director of the Melville Laboratory; Oren was promoted to Professor in 2015. During the 2013-2014 academic year, Oren was on sabbatical at Tsinghua University as a Xuetang Visiting Professor in Chemistry. His research group is interested in dynamic supramolecular self-assembly at interfaces. Oren’s current research projects include the application of macrocyclic host-guest chemistry using cucurbit[n]urils in the development of novel supramolecular hydrogels and microcapsules, drug-delivery systems based on dynamic hydrogels, the conservation and restoration of important historical artefacts through the exploitation of supramolecular polymer chemistry and sensing and catalysis using self-assembled nanophotonic systems.