BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:Bespoke Crystals: Using Bio-Inspired Approaches to Generate Cryst als with Target Properties - Prof. Fiona Meldrum\, Professor of Inorganic Chemistry\, School of Chemistry\, University of Leeds DTSTART:20160513T130000Z DTEND:20160513T140000Z UID:TALK62659@talks.cam.ac.uk CONTACT:Dr. Hernandez-Ainsa DESCRIPTION:Crystals are typically pictured as solids with regular\, geome tric morphologies and planar faces\, where the overall symmetry is determi ned by the underlying atomic-scale packing. Turning to biology\, however\ , we are met by biominerals such as seashells\, teeth and bones\, whose hi erarchical organization\, composite structures and complex morphologies ch allenge many of these ideas. Biominerals therefore provide a unique inspi ration for the design and synthesis of new materials.\n\nThis talk explore s how bio-inspired approaches can be used to control the properties of syn thetic crystals. Looking first at the composite structures of biominerals \, even single crystal biominerals contain proteins embedded within the cr ystal lattice. Here\, we adapt this biogenic strategy to create a wide ra nge of single-crystal nanocomposites. Using particles rather than protein s as simple crystal growth additives\, we show that it is possible to achi eve high levels of particle occlusion by tuning the particle surface chemi stry and the crystal growth conditions. Measurement of the mechanical pro perties demonstrates that occlusion of block copolymer micelles generates “artificial biominerals” with hardnesses comparable to those of biogen ic calcite. We then extend this strategy to investigate the occlusion of amino acids within calcite and show that we can systematically tune the am ounts occluded over a large concentration range. Determination of the hard nesses of these series of samples then enables us to determine the mechani sm of hardening in these samples. Finally\, our strategy can be extended t o generate nanocomposites in which inorganic nanoparticles are uniformly d istributed throughout a crystal matrix with true nano-scale mixing.\n\nWe then build on these results to explore the use of mixtures of additives to control crystallisation. As this potentially opens up a vast reaction sp ace\, we have employed combinatorial approaches\, guided by genetic algori thms\, to rapidly identify combinations of additives that give crystals wi th target properties. This approach is inspired by the diversification st rategies observed in natural evolution\, and uses selection\, recombinatio n and mutation strategies to rapidly identify and optimise the reaction co nditions. We show that such combinatorial methods can be used in conjunct ion with high-throughput screening to rapidly identify combinations of sma ll organic molecules capable of directing the formation of photoluminescen t quantum dot minerals in aqueous solution and at room temperature.\n\nFin ally\, we employ microfluidic devices to study crystallisation processes. With features such as flow\, confinement\, and spatial organisation\, the se devices provide excellent mimics of biomineralizing systems\, and – t hanks to their optical transparency – we can watch individual crystals g row. We use these to examine the mechanisms of calcite growth and show th at small molecules additives do not affect the morphologies until the crys tal are almost micron-sized. We also carry out crystallisation within a m icrofluidic “crystal hotel” and demonstrate that we can use it to comb ine biogenic strategies including constrained physical environments\, solu ble additives\, tailored reaction conditions and surface functionalities t o generate single crystals with pre-defined macroscopic shapes\, patterned microstructures and crystallographic orientations.\n LOCATION:Small Lecture Theatre\, Cavendish Laboratory END:VEVENT END:VCALENDAR