Title: High temperature nanomanufacturing for emerging applications

Spaker: Dr. Yonggang Yao, University of Maryland

Date/Time: 10:00-11:30 AM, Jan. 7, 2019

Abstract:

High temperature processing can provide sufficient activation energy for materials’ compositional, structural, and morphological evolutions, and is essential for various kinds of reactions, synthesis, and post-treatment. However, the current high temperature heating sources, mostly furnaces, are far from satisfying for nanomaterials processing owing to their bulky size and limited temperature and ramp range (~1300 K, ~10 K/min).

In this talk, we will discuss using electrical triggered Joule heating as a new route for high temperature engineering of nanomaterials toward scalable nanomanufacturing. We developed facile, highly stable and controllable heating strategies for micro/nanoscale high temperature engineering. Ultrahigh temperature annealing (>2500 K) is applied to carbon nanomaterials for rapid graphitization with significantly improved crystallinity and importantly, the rapid heating (~100 K/min) leads to junction welding at junctions, forming 3D interconnected carbon with greatly enhanced properties. Ultrafast thermal shock (~2000 K in 55 ms) is applied to metal salt loaded carbon substrates for in-situ synthesis of ultrasmall, well-dispersed nanoparticles. By varying the composition in salt mixtures, we synthesized bimetallic, multimetallic and high entropy alloy nanoparticles (HEA-NPs) containing up to 8 different and immiscible elements. The high temperature engineering on nanomaterials are also highly facile, energy-efficient, and reliable toward scalable nanomanufacturing.