Controlling the assembly of 2D materials at nanoscale has a significant effect on the performance of energy storage and coating materials. Employing circumferentially uniform air flow through the sheath layer of the concentric coaxial nozzles, air-controlled electrospray utilize both high electric field and controlled air flow which can offer i) enhanced stretching of fluid drops, and thus much higher throughput than conventional electrospray processes, and ii) better control of stacking of 2D nanomaterials such as graphene oxide (GO) and graphene in a droplet even at high loadings. The ability to tailor the stacking of GO sheets in droplets in the directly deposited silicon/graphene hybrid anode was demonstrated by varying air flow rates in air-controlled electrospray. The cross section SEM and HRTEM images reveal that graphene layers can be completely flattened and stacked on top of a conformal surface by applying high speed air to electrically charged droplets of graphene solution, while silicon nanoparticles (Si NPs) are incorporated into the spaces between sheets. The interconnected network of stacked graphene ensures the excellent conductivity, and the space between Si NPs and stacked graphene provides the space needed for volume expansion of Si particles.
Yong Lak Joo is the BP Amoco/H. Laurance Fuller Professor in the School of Chemical & Biomolecular Engineering at Cornell University. He received his B.S. degree at Seoul National University in Korea in 1989, and received his Ph.D. in Chemical Engineering at Stanford University in 1993. From 1993 and 1999, he was a senior research engineer at Hanwha Chemical Corporation in Korea. Prior to joining Cornell in 2001, Yong Lak Joo did two years of a postdoctoral research in the Department of Chemical Engineering at MIT.
His research focuses on the integration of molecular details into a macroscopic level in nanomaterials processing. In particular, he has recently laid the new foundation for experimental and theoretical studies on advanced, scalable nano-manufacturing processes based on the flow instability such as gas-assisted electrospinning and air-controlled electrospray. He is a fellow of American Institute of Chemical Engineers (AIChE). He received a 3M Faculty Award and is a recipient of a National Science Foundation CAREER Award and a DuPont Young Professor Award. He also received an Excellence in Teaching Award in College of Engineering, Cornell University.
JMC (originally the Jeil Moolsan Company) is a South Korean fine chemical manufacturer. JMC was established in 1953 and was acquired by the KISCO group in 2004. JMC produces high quality materials for reactive dyes, medicinal intermediates, electronics, plastics and agriculture. JMC is also a large-scale manufacturer of saccharin, a safe, high intensive sweetener that enables a drastic reduction in sugar content. JMC supplies saccharin to some of the world's largest, quality-oriented, multinational, food and medicine producers. At IDTechEx 2019, JMC is introducing its large scale Graphene Oxide and reduced Graphene Oxide production.