Welcome to the website of Dr. Mujibur Khan’s research group at the Nanomaterials Research Laboratory. Our group is involved in research related to the synthesis and characterization of novel nanoscale functional materials. Our investigations are focused on harnessing the superior physical and transport properties of nanomaterials to produce advanced materials for biomedical, structural and energy applications. Some of the major research projects currently being undertaken by our group are:
Electrospinning of nanofibers for biomedical and structural applications
Electrospinning is a versatile process for fabricating nanoscale fibers from a jet of polymer solution drawn in the presence of a high voltage electrostatic field. Electrospun nanofibers can be customized for various applications in structural materials, filtration or separation membranes and also in biomedical applications such as drug delivery, wound dressings and tissue engineering.
The lab is equipped with a state-of-the-art MECC NF-500 Electrospinning Unit, which was acquired through funding provided by an NSF MRI grant. This is a semi-industrial scale unit capable of high volume production of micro- and nanofibers. It is a fully customizable unit capable of optimum control of processing parameters for continuous and high quality fiber production. Fibers of various morphologies and functionalities can be produced through selection of a variety of spinneret and collector configurations.
The goal of our research in this field is to develop a targeted and sustained release drug delivery system for cancer therapy. Relevant research activities which we are currently performing in this area are concerned with the production of biocompatible nanofibers with core-sheath morphological structures, which function as carriers or reservoirs for anti-cancer drugs.
We have electrospun nanofibers and microfibers of structural polymers such as poly(acrylonitrile) (PAN), poly(vinylidenefluoride) (PVDF), poly(vinylpyrrolidone) (PVP). We have also performed melt-electrospinning of Ultra high molecular weight polyethylene (UHMWPE).
Functionalized adsorbent membranes for CO2 capture
We have fabricated PAN nanofiber membranes functionalized/loaded with crystalline metal oxide MOF nanoparticles for implementation as a carbon dioxide (CO2) capture system. The produced membranes are being used to design and fabricate a prototype multi-canister CO2 filter to be tested for CO2 capture efficiency from flue gases.
Hybrid Polymer Nanocomposite Fibers
We have investigated the synthesis and fabrication of a hybrid nanocomposite fiber system based on a combination of Ultra-high molecular weight polyethylene (UHMWPE) with a secondary flexible polymer phase (Nylon-6), reinforced with carbon nanotubes. The goal of this work is to implement a high performance multi-phase fiber system possessing mutually exclusive properties of both high strength and toughness.
Spinning of fibers from Ultrahigh molecular weight polyethylene (UHMWPE) using conventional melt extrusion process is challenging due to its very high entanglement density and melt flow viscosity. We have implemented a production process for fabrication of hybrid nanocomposite fibers from a blend of UHMWPE, Nylon-6 and single-walled carbon nanotubes (SWCNT), using our lab-scale solution spinning line.
Thermopower of Extrinsically Doped SiC/SWCNT Composites
We have performed experimental investigations of the thermoelectric performance of composites of silicon carbide (SiC) and extrinsically doped semiconductive single-walled carbon nanotube (SWCNT) composites. A novel sol-gel based process combined with high-temperature sintering in a vacuum tube furnace was developed to synthesize these thermoelectric composites. The Seebeck coefficients of pristine SiC/SWCNT composites were compared with those of SiC/SWCNT doped with P-type (Boron) and N-type (Phosphorous) sol-gel diffusants. Our investigations showed a significant increase in the Seebeck coefficient upon doping of the thermoelectric SiC/SWCNT composites with B-P.