Saad A. Khan - Fellow, Elected 2020

Chemical Engineer

Fellow, Elected 2020

Saad Khan’s foray into rheology started with his doctoral dissertation with Robert Armstrong at MIT on the rheology of liquid foams where they were the first to develop a two dimensional analytic model of foam bubble dynamics. He also developed a clever approach to eliminate wall slip, enabling experimental investigation of the behavior of foams, the essence of which has since been adopted by many researchers. After postdoctoral training with Ronald Larson at ATT Bell Laboratories working on experiments and modeling of polymer melts in shear, biaxial and uniaxial flows, Saad spent five years in industry prior to joining NC State University, where he is currently the INVISTA Professor and Director of Graduate Program. At NC State, Saad has supervised over 50 PhD students and published over 140 peer-reviewed papers in rheology related fields (out of a total of 220). His work has been highly cited (hindex 67 Google Scholar with over 19000 citations, including 25 rheology-based papers that each have >100 citations). He holds 20 patents.

A hallmark of Khan’s research has been his ability to enter new fields, make a substantial impact, and then translate his discoveries to enabling technologies. Saad was one of the first to use enzymes to modulate rheology of biopolymer solutions/gels. His work relating enzymatic degradation to rheology is groundbreaking, and resulted in several patents in the area of hydraulic fracturing. Saad demonstrated for the first time an in situ approach to monitor photo-gelation of polymers in real time and further correlated the rheology with real-time spectroscopic measurements. His approach has influenced many researchers and is the basis for commercial fixtures developed by rheometer companies. Saad pioneered a unique approach to plasticize polymer melts using supercritical CO 2 . Such plasticizers are highly desirable as they are transient and not a part of the final product. Saad demonstrated an extrusion-based method to measure the rheology of such systems, along with a theoretical framework to extract useful information from the measurements. These results formed the basis for development of novel composites and foams. His papers on fumed silica colloids represent some of the most comprehensive studies on correlating particle surface chemistry and rheology, especially in elucidating the role of hydrogen-bonding interactions, shear thickening and yield stress. Insight from these studies has led to the development of gel electrolytes for lithium batteries.

Saad has played a prominent role in SoR activities, including serving as session organization/chair of SoR and ICR meetings and on the SoR membership committee. Most noteworthy are his being technical co-organizer of two SoR annual meetings in Hilton Head SC (2001) and in Santa Fe NM (2010), and the local chair of the recent 2019 Annual SoR meeting in Raleigh. Saad was instrumental in bringing this meeting to North Carolina for the first time.