题目：Multi-functionality of Carbon Nanofiber Reinforced Polymer Nanocompositesaterials
报告人: Dr. Li Sun（Associate Professor of Mechanical and Materials Engineering, University of Houston, Houston, TX 77204-4006, firstname.lastname@example.org）
With the interest of polymer composites shifted toward nanoscale fillers, material synthesis quality control and throughput becomes very important. In our recent study, low cost the vapor-grown carbon nanofibers (VCNFs) were used to replace the common carbon nanotubes in synthesizing multifunctional elastomer based nanocomposites. To improve processing reproducibility, a multi-step dispersion and micro filtration process was developed to assemble the loose CNFs into self-supportive paper sheets form and become a novel platform to achieve multifunctionality. For synthesized CNFs- polydimethylsiloxane (PDMS) composites, mechanical measurements show that the interfacial bonding can be significantly improved by acid-treatment. At the same time, the resistance of composites shows significant changes upon deformation. These discoveries demonstrate that carbon nanofibers in the form of paper sheets can have extensive application potentials in developing lightweight and high strength composites that can have self-sensing and structure health monitoring capabilities. With further controlled electrodeposition of ferromagnetic materials on CNF surface, these composites can also have improved electromagnetic field shielding and static discharge characteristic together with improved vibration damping and noise reduction functions. To better understand the mechanical, electrical and coupled electromechanical properties of the nanocomposite, multi-scale numerical simulation based on three dimensional Monte Carlo simulation and finite element simulations were performed to validate experimental observations.
Dr. Li Sun received the diploma degree in physics from Nanjing University in 1993 and the Ph.D. degree in Materials Science and Engineering from Johns Hopkins University in 2002, respectively. He then joined Materials Research Science and Engineering Center in Johns Hopkins University as a NSF Postdoctoral Research Fellow. In 2003 Dr. Sun joined University of Houston as a Bill D. Cook endowed Assistant Professor of Mechanical and Materials Engineering. In 2009, he was promoted to be an Associate Professor of Mechanical and Materials Engineering. His research interest includes: nanomaterials fabrication and manipulation; multifunctional polymer composites, spintronics; ferroelectric materials, application of nanostructure materials in sensoring and biomedical devices. He has published 80 papers on SCI cited journals, with over 1200 total citations.