Speaker：Prof.Yuris Dzenis（University ofNebraska-Lincoln, USA）
Time：May 19th, 2025 at 10:00 AM
Location: Lecture Room 324,AISMST
Abstract:
Classical manufacturing techniques of advancedpolymer fibers rely on a combination of high polymer crystallinity and highdegree of macromolecular alignment to achieve superior mechanical properties.As a consequence, high-performance fibers such as PPTA and UHMWPE possess highstrength, but low strain to failure and toughness. Our mechanical andstructural analysis of electrospun nanofibers (NFs) in the ultrafine (50-250nm) diameter range showed extraordinary simultaneous improvements in strength,modulus, and toughness. The finest nanofilaments exhibited strength on the parwith that of advanced structural fibers, while exceeding their toughness byover an order of magnitude. This lecture will discuss supramolecular mechanismsof such an unusual mechanical behavior as well as review methods of structuralcharacterization of ultrafine continuous nanofibers. Prospects and impacts onwellbeing and sustainability of future textiles will be discussed.
Biography:
Dr.Yuris Dzenis is a McBroom Professor of Engineering at UNL. He has earned hisPhD in Aerospace and Mechanical Engineering from the University of Texas, PhDin Physics and Mechanics of Polymers from Latvian Academy of Sciences, and MSin Physics (Electrodynamics of Continua) from Latvian University. He has been aresearch fellow at the Institute of Polymer Mechanics, Latvian Academy ofSciences, a research scientist at the Institute of Polymer Science, Universityof Akron and the Institute of Composite Materials, University ofKaiserslautern, and a visiting professor at Doshisha University, Kyoto (twice),University of Canterbury, Christchurch, New Zealand (Erskine Fellow – threetimes), University of Paris-VI (Sorbonne-U, twice), and University of Trento,Italy. Dr. Dzenis’ research interests are in design, manufacturing, modeling,and characterization of advanced nanofibers, composites, and products. He hasdeveloped and studied a number of unusual composite materials includingcomposites with aggregating and hollow inclusions, particulate/fiber hybrids,high-performance continuous polymer, carbon, and ceramic nanofibers,hierarchical nano/micro fiber composites, and mechanically biomimetic softnon-linear nanofilamentary vascular grafts. He has introduced and developedseveral nanomanufacturing and hybrid manufacturing technologies to producefunctional nanomaterials. He has introduced a concept of nanoreinforcement ofinterfaces and pioneered development of cost-effective delamination resistantnanoengineered structural composites. Most recent advances included thediscovery and explanation of simultaneously high strength and toughness ofultrafine continuous nanofibers. Dr. Dzenis is a member of six professionalsocieties and has been an invited or plenary speaker at numerous internationalconferences on nanotechnology, materials, mechanics, NDE, and composites. Hehas written two invited perspectives on continuous nanofibers and structuralnanocomposites for Science. He currently serves as a chair of the NDPD Divisionof ASME and is an associate editor of three journals. Research from Dzenisgroup was featured on covers by ACS Nano, Nature (The Year in Science specialissue), Advanced Functional Materials, Polymer, ACS Applied Materials &Interfaces, and highlighted by Nature and the National Science Foundation,among other outlets.