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Seminar: Fluid Mechanics

Assembly of nano-sized building blocks into high performance macroscopic materials

Speaker: Nitesh Mittal
Organization: KTH, Mekanik
Time: 2018-04-05 10:30
Place: Teknikringen 8

Abstract

Excellent strength of nanoscale building blocks in materials is due to their near‑perfect and defect-free structural arrangement. It is exceedingly challenging to devise nanostructuring strategies for translating such high intrinsic properties to macroscopic materials. Cellulose, the most abundant structural element on Earth, has theoretically been perceived as strongest and stiffest among the natural polymeric materials in its nanoscale crystalline form. However, these superior properties are yet to be realized for nanocellulose-based macroscopic structures. In this seminar, I will talk about the fabrication of nanocellulose fibres in pursuit of maximal mechanical performance, by hydrodynamically controlling the structural ordering of nanofibrils. We employ high intensity X-rays and polarized optical microscopy to examine fibril orientation and diffusion. The flow-assisted process results in fibres with highly-ordered and strongly interacting arrangement of nanoscale building blocks. The Young’s modulus of the fabricated fibres reaches up to 86 GPa and a tensile strength of 1.57 GPa, which are substantially higher than any natural or synthetically prepared bio-based material reported till date.​