Speaker: Prof. Li SUN

Title: New Generation of Dissolvable Alloys and Polymers

Time: 9:00am - 10:30am, December 24, 2018

Location: Room 502, School of Civil Engineering

ABSTRACT: Conventional wisdom is that the more stable and strong of an engineering material, the better performances and wider applications of such a material.  While this is generally true, degradable materials are finding their ways into our daily life, mainly in the areas of environmental friendly polymers and bio-degradable alloys for certain medical devices. But except for these limited applications, it is safe to say that degradable materials remain understudied For this talk, we will present the recent research and development of magnesium based alloys and a PVA family of polymer that can sustain extreme pressure (900MPa) and temperature (120oC) and disintegrate after use. Combination of the two new types of materials leads to the development of revolutionary dissolvable hydraulic fracturing plugs (frac plugs) which eliminate the need for a separate milling intervention to achieve a full-bore inner diameter flux after fracturing. The Mg based dissolvable metals can have better mechanical performances than the current glass fiber reinforced polymer composite materials, and the PVA based polymers can be completely dissolved in water. Tuning the chemistry, processing and heat treatment and thus the microstructure of Mg alloys allows the wide range of adjustment of metal strength, ductility and electrochemical dissolution rate.  In the meanwhile for the PVA, peculiar effects of water induced a plastic to elastic transition which is still under investigation.  Considering the fact that the replacement of conventional composite and rubber with dissolvable alloys and elastomer can lead to new frac plug design, this project can lead to the production of high performance degradable/dissolvable frac plugs with new feature and designs.

Resume of Prof. Li Sun:

Biography: Dr. Li Sun is currently an Associate Professor of Mechanical and Materials Engineering at the University of Houston. He is also a faculty member at the Texas Center for Superconductivity (TcSUH) and the Subsea Engineering at UH.  Dr. Sun received his B.S. degree in physics from Nanjing University in 1993 and a Ph.D. degree in Materials Science and Engineering from Johns Hopkins University in 2002. He holds the Bill D. Cook Professorship and is currently a Siyuan professor in Physics at Nanjing University. Dr. Sun’s main research interest is in the general area of nanomaterials fabrication, manipulation and application. His current research projects include multifunctional polymer composites, spintronics; ferroelectric materials, application of nanostructure materials in sensors and biomedical devices. He has published more than 80 papers on SCI journals with an H-index of 20.