MEMS Seminar: "Designing Materials That Make a Difference: From Soft Solids, Aerogels to Nanofibrous Structures"
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Wednesday, September 11, 2019 - 12:00pm to 1:00pm
Dr. Saad Khan | NC State University
In this presentation, we will present vignettes of various research projects in our group, the focus of which have primarily been on multicomponent soft materials. Examples will be drawn from, various classes of polymeric, colloidal, nanoparticulate and biological systems, to elucidate the relationship between material microstructure/morphology, chemistry, formulation and macroscopic behavior. We hope to illustrate this notion by using examples of (a) hybrid polymer-inorganic aerogels, where ultra-light, yet mechanically robust aerogels are developed with multifunctionality.
The degree of oleophilicity/hydrophobicity is exploited to render these materials useful in oil and chemical spill remediation while the degree of interaction between the polymer and silica is utilized to make this mechanically flexible and flame retardant; (b) photo-activated polymer hydrogels wherein we examine the gelation of alginate undergoing a two-step ionic crosslinking upon ultraviolet (UV) irradiation using in situ dynamic rheology, (c) hydrophobically-modified associative polymers and microgels in which the role of hydrophobic associations is modulated using phospholipids. The underlying interactions are examined via rheology and tribology with a goal to relate tribology to skin care applications, and (d) nanofibers templated with nanoparticles or encapsulated with functional moieties for use in sensors, regenerative medicine, and crop protection in Sub Saharan Africa.
Saad Khan is the INVISTA Professor & Director of Graduate Program in the Department of Chemical & Biomolecular Engineering at North Carolina State University. Research in the Khan Research Group focuses on soft-solids: gels, colloids and associative networks. Of particular interest is the relationship between material microstructure, chemistry, and macroscopic properties. The use of rheology with other techniques provides a powerful and unique combination to understand and describe the macroscopic behavior of structured systems in terms of their underlying chemistry and/or microstructure. This has resulted in focusing in many different areas over the years, including enzymatic modification of water-soluble polymer and gels, photo crosslinked polymers, self-assembled nanoparticulate silica and nanodiamond gels, associative polymer interactions with surfactants and cyclodextrins leading to applications in coatings, drug delivery, energy storage device and hydraulic fracturing, to name a few. More recently the group has made forays to other areas such as crop protection for enhanced food security as well as examining multifunctional systems composed of nanofibrous structures and aerogels. The group has had over 50 PhD (including current) students resulting in over 200 publications (h index 54 ws) and over 16 patents. Khan received his bachelor’s degree from Princeton University and his PhD from MIT, both in chemical engineering.
Lunch will be served at 11:30 am.
Hosted by Dr. Michael Rubinstein