BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//University of Liverpool Computer Science Seminar System//v2//EN
BEGIN:VEVENT
DTSTAMP:20260922T104746Z
UID:Seminar-dept-1039@lxserverM.csc.liv.ac.uk
ORGANIZER:CN=Lutz Oettershagen:MAILTO:Lutz.Oettershagen@liverpool.ac.uk
DTSTART:20230315T130000
DTEND:20230315T140000
SUMMARY:School Seminar Series
DESCRIPTION:Prof. Nicholas Kotov: Chirality-Complexity Relations and Graph Theory of Nanostructures\n\nSince Leonardo Da Vinci discoveries in science and\n\nengineering were inspired by evolution-optimized geometry of\n\nmolecules, tissues, and organisms found in biology using\n\nnon-biological preparatory techniques. Chiral nanostructures – a large\n\nand rapidly evolving class of metal, semiconductor, and ceramic\n\nmaterials is one of these materials. Besides fascinating optical,\n\ncatalytic, and biological properties, the studies of chiral\n\nnanostructures revealed something more. Unlike other geometric\n\nproperties, mirror asymmetry is invariant to scales. Thus, the\n\nsynthesis and self-assembly of chiral nanostructures showed how basic\n\ngeometric properties of Nature’s smallest building blocks can produce\n\nhighly complex and adaptable structures at macroscale.\n\n\n\nAnalysis of the hierarchically organized micro- and macrostructures\n\nobtained by self-assembly of the chiral nanoparticles (NPs)\n\ndemonstrated the mechanism of emergence of effective complexity in\n\nsuch systems and how such diversity of the building blocks contributes\n\nto it. These findings became possible by applying graph theory (GT)\n\nfor calculation of the quantitative measures of their complexity by\n\ndescribing the constituent NPs as nodes and the interfaces between\n\nthem as edges of graphs. Taking an example of hierarchically organized\n\nparticles with twisted spikes from polydisperse Au-cystein\n\nnanoplatelets [1], we found that (a) formation of complex structures\n\ndoes not require monodispersity; (b) complexity index (CI) of the\n\nsynthetic particles can be higher than biological prototypes; and (c)\n\ncomplexity emerges from competing chirality-dependent assembly\n\nrestrictions. The GT description of chiral hedgehogs can also be\n\nexpanded to other nanoscale structures creating analogs of chemical\n\nformulas for particle systems [2]. Among other outcomes of the\n\nanalysis of the chirality-complexity relations, GT-based description\n\nof nanostructures leads to quantitative description of biomimetic\n\nmaterials combining order and disorder that is essential to their\n\nfunctionality. Expansion of GT principles from particles to composites\n\nenabled transition from inexact approach of their good-luck-based\n\nengineering to function-driven design encompassing multiple\n\nproperties. While this work is still in progress, the methods of\n\nGT-based biomimetic materials engineering can be demonstrated by the\n\nmultiparameter optimization of complex networks of aramid nanofibers\n\nfor batteries for robotics [3] and biomedical implants [4].\n\n\n\nReferences\n\n[1] W. Jiang, et al, Emergence of Complexity in Hierarchically\n\nOrganized Chiral Particles, Science, 2020, 368, 6491, 642.\n\n[2] S. Zhou, et al, Chiral assemblies of pinwheel superlattices on\n\nsubstrates, Nature, 2022, 612, 259.\n\n[3] Wang, M.; Vecchio, D.; et al Biomorphic Structural Batteries for\n\nRobotics. Sci. Robot. 2020, 5 (45), eaba1912.\n\n[4] H. Zhang, et al Graph Theoretical Design of Biomimetic Aramid\n\nNanofiber Nanocomposites as Insulation Coatings for Implantable\n\nBioelectronics, MRS Bulletin, 2021, 46, 7, 576.\n\n\n\nAbstract with images:\n\nhttp://kurlin.org/MIFplusplus/15March2023-Nicholas-Kotov.pdf\n\nhttps://www.csc.liv.ac.uk/research/seminars/abstract.php?id=1039
LOCATION:Gossage Lecture Theatre, Chemistry
END:VEVENT
END:VCALENDAR