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NSF awards Dr. Lei Li with $263,379 grant to study polymer coatings on solid surfaces

PITTSBURGH  (August 29, 2012) … Lei Li, PhD, assistant professor of chemical and petroleum engineering at the University of Pittsburgh Swanson School of Engineering, has been awarded a $263,379  Civil, Mechanical and Manufacturing Innovation  (CMMI) grant from the National Science Foundation for "Understanding the Mechanism of Simultaneous Oleophobic/Hydrophilic Behavior: When a Nanometer-Thick Polymer Coating meets a Solid Surface."

According to the grant abstract, the CMMI grant will elucidate the fundamental mechanism that is responsible for simultaneous oleophobic/hydrophilic behavior observed on the solid surface coated with a nanometer-thick polymer. Although surfaces more wettable to water than to oil have many important applications, such surfaces have been very rarely reported. Recent studies indicate that such anomalous wetting behavior could be achieved by applying some nanometer-thick polymer coating on some solid substrate. However, the mechanism responsible for the interesting and puzzling result remains unclear to date. To understand the mechanism, the PI will investigate how exactly the polymer-substrate interaction affects the "static" and "dynamic" holes in the polymer nanofilms by x-ray reflectometry (XRR) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) to establish the kinetics of the wetting process of water and oil. The PI also will identify the key parameters, including polymer structure, substrate structure, and photochemical irradiation process, that govern simultaneous oleophobicity/hydrophilicity.

If successful, the underlying mechanism of simultaneous oleophobicity/hydrophilicity will be discovered, and design criteria will be established. Simultaneous oleophobic/hydrophilic surfaces are highly desirable in many important applications, including detergent-free cleaning, anti-fogging, and oil-water separating. Understanding how to fabricate such surfaces will greatly impact the field of environment and energy. The research project also will promote the participation of the students from underrepresented groups in science and engineering fields, including providing research training to graduate and undergraduate students, developing new courses, and conducting outreach activities, such as the ENGAGE program that recently was established at the University of Pittsburgh under the PI's direction. Through multi-faceted activities, the PI will promote interest and participation in science and engineering disciplines on the part of students of all ages.

About Dr. Li 

Dr. Lei Li joined the Swanson School from Seagate Technology LLC where for nine years he researched ultrathin film (2nm or thinner) for nanotribology application. His current research interest focuses on polymer thin and ultrathin films at surfaces and interfaces. The key is to understand the polymer/polymer and polymer/substrate interactions governing the various properties, e.g. mechanical, optical, electrical and tribological properties, of polymer thin films. Based on this understanding, novel materials are developed for applications in nanotechnology and bio-systems. Examples are:
• Relaxation and dynamics of polymer thin films on various substrates 
• Mechanical properties of polymer thin films 
• Ultrathin perfluorinated polymer films for anti-friction and anti-corrosion application in micro and nano devices 
• Novel composite polymer thin films with low friction and wear for biomedical implants 
• Fabrication of polymer thin films with low surface energy and enhanced anti-adhesion properties via photochemistry approach

Dr. Li earned his bachelor's and master's degrees in chemical engineering from Tsinghua University, and his PhD in macromolecular science and engineering from the University of Michigan.