题 目: Research on the Controlled Synthesis and Property Study of Ultralong Carbon Nanotubes and Nanofiber-based High-efficiency Particulate Aerosol Filtration
主讲人 : 张如范/助理教授，特聘研究员
主持人 : 危仁波/副教授
时 间 : 2018年7月3日（周二），10点0分
地 点 : 沙河校区211楼408B会议室
Dr. Rufan Zhang received his B.E. from Department of Chemical Engineering, China University of Petroleum (Beijing) in 2009 and received his Ph.D. from Department of Chemical Engineering, Tsinghua University under the supervision of Prof. Fei Wei and Assoc. Prof. Yingying Zhang in 2014. From Nov. 2014 to Dec. 2017, he was a postdoctoral scholar in the Department of Materials Sciences and Engineering at Stanford University, USA under the supervision of Prof. Yi Cui. From Jan. 2018, he works as an assistant professor in the Department of Chemical Engineering, Tsinghua University. Dr. Zhang has published 42 peer-reviewed papers on journals such as Nature Nanotechnology, Nature Communications, Chemical Society Reviews, Accounts of Chemical Research, Advanced Materials, ACS Nano, Nano letters, etc., which have been cited for more than 2400 times with H-index of 19. He obtained 6 authorized patents and wrote 4 book chapters. He obtained many awards such as First Prize of the Natural Science Award for Outstanding Achievements of Scientific Research, Dimitris N Chorafas Foundation Award, Top 10 Graduate Students of Tsinghua University, etc.
In this talk I will talk about two different topics: ultralong carbon nanotubes (CNTs) and nanofiber-based high-efficiency particulate aerosol (HEPA) filtration.
In the first topic section, I will talk about ultralong CNTs, which usually refer to the horizontally aligned CNT arrays, with lengths up to centimeters or even decimeters, grown on ﬂat substrates by chemical vapor deposition. Ultralong CNTs follow tip-growth mode and have large intertube distances, resulting in a low defect density. Due to their perfect structures and extraordinary thermal, electrical and mechanical properties, they show great potential as building blocks for transparent displays, nano electronics, quantum lines, field emission transistors, superstrong ﬁbers, aeronautics & astronautics materials, and even space elevators. I will talk about the growth mechanism of ultralong CNTs based on Schulz-Flory distribution, the controlled synthesis of ultralong CNTs with perfect structures and macroscale lengths, the optical visualization and feasible manipulation of single CNTs, the mechanical, electrical, and thermal properties of ultralong CNTs, and the macroscale superlubricity in centimeters long double-walled CNTs.
In the second topic section, I will talk about nanofiber-based HEPA filtration. As is widely known, there are serious haze problems in recent years in many developing countries. HEPA filtration is an effective way to remove aerosol particulate matters for both indoor environment protection and personal protection. Electrospun nanofibers are found to be an effective and cost-competitive candidate for HEPA filters. In this section, I will talk about the in-situ investigation on the process and mechanism of the aerosol capture on nanofibers, the factors affecting the aerosol capture efficiency, the fabrication of HEPA filters which can work at high temperature, and the effective transfer and electrospun nanofibers.